Darwin says "just so..."

How ZEBRA got her stripes

2012-02-15T05:02:00.004-08:00

According to Gábor Horváth and his team in their recent publication in the Journal of Experimental Biology, the zebra stripe hide pattern is the least attractive to voracious horsefiles.

According to Horváth, these insects are attracted to horizontally polarized light because reflections from water are horizontally polarized and aquatic insects use this phenomenon to identify stretches of water where they can mate and lay eggs. Blood-sucking female tabanids are also guided to victims by linearly polarized light reflected from their hides.

The team measured the stripe widths and polarization patterns of light reflected from real zebra hides and they found that the zebra's pattern correlated well with the patterns that were least attractive to horseflies.

Horváth concluded that zebras evolveded a coat pattern in which the stripes are narrow enough to ensure minimum attractiveness to tabanid flies : "The selection pressure for striped coat patterns as a response to blood-sucking dipteran parasites is probably high in this Africa."

Story Teller: Scientist Gábor Horváth and team, Hangary, Sweden
Source: How the Zebra got its stripes

How WHALE got his big mouth

2011-08-27T09:05:00.000-07:00

According to the researchers an ancient jawbone showed that nature's largest mouths probably evolved to suck in large prey rather than to engulf plankton-filled water. The prehistoric jaw, was very different from modern baleen whales where the lower jaw does not fuse at the "chin". Instead there is a specialised jaw joint that allows each side of the jaw to rotate. By having two curved lower jaw bones that rotate in this way, baleen whales are able to produce huge gapes to take in massive quantities of water and prey.

Lead researcher, Erich Fitzgerald said: "This is compelling evidence that these archaic baleen whales could not expand and rotate their lower jaws, which enables living baleen whales to engulf and expel huge volumes of seawater when filter feeding on krill and other tiny animals."

Crucially though, the fossilised whale, named Janjucetus hunderi, did have a very wide upper jaw. Dr Fitzgerald says that this widening was the earliest step in the evolution of today's whales' gigantic mouths "I was able to discover the sequence of jaw evolution from the earliest whales to the modern giants of the sea," he said. "The loose lower jaw joint that enables living baleen whales to greatly expand their mouths when filter feeding evolved later."

Storyteller : Erich Fitzgerald from the Museum Victoria in Melbourne
Source: Fossil shows huge mouth evolution

Story Researcher: Richard Sternberg
Source: Whale Evolution Vs. Population Genetics - Richard Sternberg

How BEE designed her nest

2010-12-30T12:11:00.000-08:00

Females from a newly discovered "solitary" species build the perfect environment for their eggs according to scientist Jerome Rozen.

This bee makes a "petal sandwich" out of two layers of flower petals inside a small burrow it digs in the ground, cementing them together with clay or mud. When the physical structure is ready it gather provisions of a sticky mix of nectar and pollen and places it on the chamber's floor. An egg is deposited on its surface, and the chamber is closed by carefully folding the petals at the top. The nest is capped with a plug of mud, sealing the young bee in a humid chamber that becomes rigid and protects the larvae as it eats its rations, spins a cocoon, and falls into a 10-month sleep until spring.

"They've found a way of protecting this immature stage by creating an environment with fairly high humidity," Rozen said. "The humidity is high because the chamber is constructed with two layers of petals with mud in between, which means the food will not dry out when the larvae feeds. Meanwhile the outside becomes very hard like a nut. This makes it very comfortable and very safe because nothing's going to come down and crush them. Anything that wants to eat them from above is going to have a hard time. We are most intrigued by its beauty and as an evolutionary mechanism for protecting offspring".

Storyteller: Jerome Rozen, Curator , American Museum of Natural History.

Source: Rare Bees Make Flower-Mud "Sandwiches"

How SNAKE got GROOVY

2010-12-05T00:38:00.000-08:00

According to Jon Mitchell from the University of Chicago, "A SET of 200-million-year-old teeth from a beast related to dinosaurs and crocodiles has shed light on how snake fangs evolved. They support the idea that venom canals inside fangs evolved from grooves on the tooth surface." Jon and his colleagues discovered 26 Uatchitodon teeth that shows how grooves initially formed at the surface and gradually lengthened and deepened until they became enclosed canals. Bryan Grieg Fry from the University of Melbourne, Australia, is convinced this is the case, and says the fossil series is "fantastic".

Storyteller: Jon Mitchell, University of Chicago and Bryan Grieg Fry, University of Melbourne

Source Snake fangs evolved from groovy teeth

Also see: How SNAKE got his fangs

How LEOPARD got her spots

2010-11-03T01:57:00.000-07:00

A new study carried out by researchers at the University of Bristol studied 35 species of wild cats and concluded : "These very complex and irregular models on their fur have probably evolved to help the cats have a good camouflage. This link between environment and fur patterns is quite strong but after looking at the evolutionary history, we can see that these patterns can evolve but also disappear quite fast."

Some exceptions were however highlighted: Some cheetahs have spots even though they live in open spaces, while the bay cat and the flat-headed cat, who prefer closed habitats have plain coats. Also, out of the 35 species, only one cat has vertically elongated patterns, that have nothing to do with grasslands: the tiger. On the other hand, tigers seem to camouflage really good so why don't other animals have vertical stripes too?

This would confirm Rudyard Kipling's explanation of leopard's spots: the environment “full of trees and bushes and stripy, speckly, patchy-blatchy shadows”.

Storyteller: Will Allen, Unversity of Bristol School of Experimental Psychology

Source: How did leopards get their spots

How MOLE became a star

2010-09-06T08:03:00.000-07:00

This weird and wonderful creature is the star-nosed mole. It relies heavily on its remarkable star-shaped nose. This organ enables the star-nosed mole to decide whether something is edible with astonishing speed. The star-shaped nose is a highly specialized sensory-motor organ, which consists of 11 pairs of fleshy finger-like 'tendrils'. The star is divided into a high resolution central fovea region and less sensitive peripheral areas. its surface is covered with 25,000 mechanoreceptors called Eimer's organs. This makes the star ultrasensitive - it is, in fact, the most sensitive organ in the entire animal kingdom.

The star-nosed mole evolved to inhabit a wetland habitat, and so was placed under selective pressure to exploit the dense populations of small insects it found in its new environment.

Storyteller: Catania, K. Olfaction: Underwater 'sniffing' by semi-aquatic mammals.
Source: The star-nosed mole's amazing appendages

How the PELICAN got his beak

2010-07-04T10:57:00.000-07:00

The identification of an extremely well preserved 30-million-year old fossilised beak raises interesting questions over why evolution has left the birds so little changed over such a long period.
The nearly complete beak of the 30-million-year old fossil, found in the Luberon area of south-eastern France, resembles those of the seven modern pelican species so closely that it falls within the genus Pelecanus.

Pelican beaks are the longest of any living birds. Beneath the beak is a flexible pouch that allows the birds to capture their prey in the water, then spit out the water before swallowing their meal. Like other bird beaks, they are rarely preserved as fossils, so little had been known about their early evolution.

Storyteller: Antoine Louchart of the University of Lyon, France.
Source: Pelican fossil poses evolutionary puzzle

How BEETLE got his jewels

2010-04-15T08:29:00.000-07:00

According to researchers from the University of Texas, the jewel scarab species Chrysina gloriosa can distinguish between circularly polarized and unpolarized light. That ability could provide the beetles with a tremendous advantage, the researchers say, because most of the light reflected off these beetles’ colorful bodies happens to be circularly polarized. Because ability to see CP light is very rare in nature, it’s not likely that any of the beetles’ predators can see it. So the ability to both see and reflect CP light probably evolved to allow jewel scarabs to communicate with each other while staying hidden from predators

Storyteller: Parrish Brady, University of Texas
Source: Beetles stand out using Avatar tech

How DOLPHIN learnt to hear

2010-01-27T22:52:00.000-08:00

Two new studies in the January 26th issue of Current Biology, a Cell Press publication, show that bats' and whales' remarkable ability and the high-frequency hearing it depends on are shared at a much deeper level than anyone would have anticipated -- all the way down to the molecular level.

If you draw a phylogenetic tree of bats, whales, and a few other mammals based on similarities in the prestin sequence alone, the echolocating bats and whales come out together rather than with their rightful evolutionary cousins.

"We were surprised by the strength of support for convergence between these two groups of mammals and, related to this, by the sheer number of convergent changes in the coding DNA that we found," Rossiter said.

Storyteller: Stephen Rossiter of the University of London
Source: In Bats and Whales, Convergence in Echolocation Ability Runs Deep

How BIRD lost his teeth

2010-01-04T02:28:00.000-08:00

According to scientists at the Chinese Acadamy of sciences in Beijing, the earliest birds went to extreme measures to address weight issues: they lost their teeth.

The team compared the body structure of a number of early birds and found that some toothed species were more adapted for flight. They think natural selection may have put pressure on weaker fliers to lose their teeth in a bid to improve their skills by losing excess weight. "It would be especially advantageous to reduce the weight of the head because [it] is further from the centre of gravity," they write.

That theory is "as good as any other", says Mike Benton at the University of Bristol, UK, though he remains sceptical. "Losing teeth wouldn't make a huge difference to balance in the air."

StoryTeller: Zhonghe Zhou at the Chinese Academy of Sciences in Beijing
Source: Early birds may have dropped teeth to get airborne

How SHARK got his hammer

2009-11-29T02:15:00.000-08:00

According to New Scientist, "It's one of evolution's most eccentric creations: a head shaped like a hammer. Now, a study suggests that the hammerhead shark may have evolved its oddly shaped snout to boost the animal's vision and hunting prowess."

For over a century, scientists have speculated why hammerheads evolved such an odd shape and whether having eyes so far apart would enhance their vision. In 1942 a leading authority on sharks, Gordon Walls, suggested the position of the shark's eyes prevented it from having binocular vision. But others have argued exactly the opposite, saying the animals must have enhanced eyesight.

Now, hammerhead sharks have had their first eye examination, and it has laid the debate to rest. Sharks with wider heads have better binocular vision – all the better to track fast-moving prey like squid with far more accuracy than sharks with close-set eyes.
The research also shows that hammerheads – among other sharks – have a 360-degree view of the world in the vertical plane, allowing them to simultaneously see prey above and below them.

Story teller: Michelle McComb of Florida Atlantic University

Source: Why the Hammer head shark got its hammer

How MOLE RAT got naked

2009-10-28T08:18:00.000-07:00

ScienceDaily - Naked mole rats are strange, ugly, nearly hairless mouse-like creatures that live in underground communities. Unlike any other mammal, these communities consist of queens and workers more reminiscent of bees than rodents
They are 3-6 inches long, have pink furless skin, tiny eyes which never see the light of day, and long front teeth for digging.

Scientists call it "eusocial" in that the young are cared for by the group, individuals in the group give up their ability to reproduce in order to do other jobs, and there are at least two generations that overlap to do the family's work, Honeycutt noted.

"Biological evolution is generally seen as a competition, a contest among individuals struggling to survive and reproduce," said Dr Rodney Honeycutt.

"It runs counter to everything we know about evolution," Honeycutt said. "In fact, (Charles) Darwin himself said social animals represent a real challenge to his theory (of natural selection and individual fitness)."

Storyteller : Dr. Rodney Honeycutt, Texas A&M Univeristy
Source: Desparate Mole-Rats

How HUMAN controlled his urge

2009-09-24T13:29:00.000-07:00

Lust is a universal preoccupation, one of the most compelling of the Seven Deadly Sins, new studies confirm. Whereas not only humans, but also birds and mammals, regularly engage in promiscuous, lecherous behaviour, researchers report that only people are capable of controlling such urges.

Studies at Northwestern University indicate that lust and cuckoldry are almost "compulsive" as a direct result of their impact on the brain's reward centres, which are foci of sensual interpretation. Erotic stimuli create a neurological frenzy.

Studies at Rutgers University, the State University of New York and elsewhere show infidelity and lewd behaviour in mammals and birds result from a "constellation of neural correlates." Researchers agree that lust probably evolved to generate mating behaviour among any appropriate partners.

Storyteller: Helen E. Fisher anthropology professor and human behavior researcher, Rutgers University

Humans alone can control lust, but most don't

How SPLEEN got some respect

2009-08-14T08:04:00.000-07:00

Scientists have discovered that the spleen, long consigned to the B-list of abdominal organs and known as much for its metaphoric as its physiological value, plays a more important role in the body’s defense system than anyone suspected.

Reporting in the current issue of the journal Science, researchers describe studies showing that the spleen is a reservoir for huge numbers of immune cells called monocytes, and that in the event of a serious trauma to the body like a heart attack, gashing wound or microbial invasion, the spleen will disgorge those monocyte multitudes into the bloodstream to tackle the crisis. “The parallel in military terms is a standing army,” said an author of the report. “You don’t want to have to recruit an entire fighting force from the ground up every time you need it.”“Often, if you come across something in the body that seems like a big deal, you think, ‘Why didn’t anybody check this before?’ ” Dr. Nahrendorf said.

“But the more you learn, the more you realize that we’re just scratching on the surface of life. We don’t know the whole story about anything.”

Storyteller: Dr Matthias Nahrendorf, Massachusetts General Hospital and Harvard Medical School

Source : Finally, the Spleen Gets Some Respect

Vestigial Organs not so useless after all, Studies find

How PTEROSAUR learnt to FLY

2009-02-19T10:55:00.000-08:00

A new study published February 17 in the journal PLoS One by researchers from Ohio University, College of the Holy Cross and the University of Leicester explains how balloon-like air sacs, which extended from the lungs to inside the skeleton of pterosaurs, provided an efficient breathing system for the ancient beasts. The system reduced the density of the body in pterosaurs, which in turn allowed for the evolution of the largest flying vertebrates.
"We offer a reconstruction of the breathing system in pterosaurs, one that proposes the existence of a mechanism with the same essential structure to that of modern birds — except 70 million years earlier," said study co-author Leon Claessens, an assistant professor of biology at the College of the Holy Cross

Storyteller: Leon Claessens, assistant professor of biology at the College of the Holy Cross
Source: Air-filled Bones Extended Lung Capacity And Helped Prehistoric Reptiles Take First Flight

How BEETLE got thirsty

2009-02-19T10:33:00.000-08:00

A new study reports that seed beetles may be seeking out intimate moments not to increase their chances of becoming fertilized, but for hydration. "We were curious about the behavior of these females—males are known to inflict damage during mating, and yet the females keep going back for more," said study lead author Claudia Ursprung.

We wanted to find out whether females were getting food or drinks from the ejaculated fluid," said Ursprung, whose research appears in a recent issue of the journal Behavioral Ecology and Sociobiology. Ursprung and her colleagues kept 79 female seed beetles in enclosures for eight days. Some were given food and water, some just food, and some just water. In the absence of water but not food, females were much more likely to try breeding. Being given water, however, left the females with little appetite for sex.

The beetles probably evolved this bizarre tactic because the species lives in a dry environment, the researchers suspect. "It is kind of like a bribe for mating, a way of ensuring that the female will produce offspring," said co-author Darryl Gwynne, also at the University of Toronto.

Storyteller: Claudia Ursprung of the University of Toronto Mississauga.
Source: Love Thirsty Beetles

How the MOCKINGBIRD became a songwriter

2009-02-10T02:45:00.000-08:00

Mockingbirds are the quintessential example of Darwinian evolution and were in fact Charles Darwin’s primary inspiration that led to his studies of evolution.
Evolutionary theory for some time seemed to point to the fact that mockingbird songs worked to attract mates, similar to the way a peacock’s feathers attract peahens. Mockingbirds, however, are monogamous birds, unlike peacocks, and both males and females sing the varied songs of their neighbors.
Different species of mockingbirds have purportedly mimicked everything from the songs of other birds, to machines, and even songs written by humans. Evidently, this proves that mockingbirds aren’t creatures of habit, even though the mimicry would seem to prove otherwise.
Evidently, songbirds learn their styles much in the same way a human child learns language. First, babbling, then practicing, until they are able to formulate their own songs. Most song birds stop, however, once they have perfected their song.
Mockingbirds, on the other hand, continue to learn and develop new sounds and songs through the duration of their lives, which seems to make the mockingbird a lover of learning new things. This skill makes it able to continuously adapt to its surroundings as well, which is another case of survival skills being put to the ultimate test.

Story Teller: The Berkley Daily Planet.
Source: “Mockingbird Jazz: The Evolutionary Roots of Bird Song,”

Story Researcher: This post was contributed by Holly McCarthy, who writes on the subject of an online university. She invites your feedback at hollymccarthy12 at gmail dot com

How NEANDERTHAL got his big nose

2009-01-19T07:54:00.000-08:00

LONDON: Anthropologists have suggested that Neanderthals had big noses because of the degree to which their face used to jut forward, indicating that the odd feature was a fluke of evolution, not some grand adaptation. The Neanderthal nose has been a matter of befuddlement for anthropologists, who point out that modern cold-adapted humans have narrow noses to moisten and warm air as it enters the lung, and reduce water and heat loss during exhalation. Big noses tend to be found in people whose ancestors evolved in tropical climates
, where a large nasal opening helps cool the body. But Neanderthals go against this trend, according to Tim Weaver, a palaeoanthropologist at the University of California, Davis. "They were living in the glacial environment of Europe, colder than it is today, for most of the time," he said. "So, it's sort of been an anomaly. Why do they have these wide nasal apertures?," he wondered.

Storyteller: Tim Weaver, Palaeoanthropologist, University of California,
Source: Why Neanderthals had big noses

How TURTLE got her shell

2008-10-10T03:50:00.000-07:00

A newly identified fossil could explain one of evolution's biggest mysteries – the origin of the turtle's shell. Bone fragments from a 210-million year-old, land-dwelling reptile from New Mexico suggest that the earliest turtles didn't have much of a shell at all. Over millions of years, rows of protective armour plates gradually fused together and to the reptile's vertebrae, eventually creating a complete shell. "Turtles ultimately originated from something that looked like an armadillo," says lead author Walter Joyce.

Exactly why turtles evolved their shell remains a mystery, Joyce says. A full shell might offer added protection and stability. And the proof could be in the pudding – their body plan is the world's oldest, changing little over 200 million years. "For some reason just being a turtle is an idea that came along and just really works," he says.

Storyteller: Walter Joyce, a palaeontologist, Peabody Museum of Natural History, Connecticut
Source: Fossil reveals how the turtle got its shell

Story research: Creation evolution headlines
Source: A turtle missing Link - Are we missing something?

How JELLYFISH got her sting

2008-09-30T00:42:00.000-07:00

Jellyfish may owe thanks to a humble bacterium for their ability to sting prey. Scientists have found that one of the genes necessary for them to sting is similar to a gene in bacteria, suggesting the ancestors of jellyfish picked up the gene from microbes. The research is published this week in Current Biology.

"The result was a great surprise," says developmental biologist Nicolas Rabet of the Pierre and Marie Curie University in Paris, France, who led the team. "[This kind of] horizontal gene transfer is often neglected, and could sometimes be more important than we thought." Unlike vertical gene transfer from parent to offspring, the horizontal variety happens between organisms, or even between different species.

According to Casey Dunn , an evolutionary biologist who studies phylogenetic problems "There are other explanations for the incongruencies they see in the tree such as coevolution", but Rabet points out that that since the PGA synthase gene is approximately 1000 bases long, it is statistically unlikely to be the product of multiple distinct genes converging on the same sequence.

Storyteller: Nicolas Rabet of the Pierre and Marie Curie University in Paris, France
Source: How the Jellyfish got its sting

Story Researcher: Dave Scot, Uncommon Descent
Source: Tree of Life gets stung by JellyFish

How HUMAN got pregnant

2008-09-23T05:20:00.001-07:00

Yale researchers have shown that the origin and evolution of the placenta and uterus in mammals is associated with evolutionary changes in a single regulatory protein, according to a report in Proceedings of the National Academy of Sciences.

Pregnancy is a biologically unusual situation where one organism lives and develops inside another that is genetically different. Ordinarily, the immune system identifies and destroys the dissimilar tissue as if it were a parasite. But in some early mammals, changes 'turned down' the immune system, allowing the developing embryo to grow and thrive unchallenged by the maternal immune response.

"New functions arise by using an existing tool from the gene regulatory 'toolbox' in a new or different place.

According to Yale graduate student Vincent Lynch, lead author of the study, "We are writing a different chapter. In this case the function of a major regulatory tool was altered — it is like we found a redesigned hammer."

Storyteller: Vincent Lynch, Yale graduate student

Source:Redesigned hammer that forged evolution of pregnancy in mammals found

How SNAKE got his fangs

2008-08-08T01:39:00.000-07:00

"Many advanced snakes use fangs—specialized teeth associated with a venom gland to introduce venom into prey or attacker. Various front- and rear-fanged groups are recognized, according to whether their fangs are positioned anterior (for example cobras and vipers) or posterior (for example grass snakes) in the upper jaw A fundamental controversy in snake evolution is whether or not front and rear fangs share the same evolutionary and developmental origin".

"Our results suggest a new model for the evolution of snake fangs. A posterior subregion of the ancestral tooth-forming epithelium became developmentally uncoupled from the remaining dentition, resulting in posterior and anterior dental laminae that are developmentally independent."

Says PZ Meyers of Pharyngula "The key innovation in snake evolution was a subtle one, an uncoupling of two tooth-generating regions that opened the door to more flexibility in the modification of the jaws. The fang/venom gland complex probably evolved once in the common ancestor of these groups, but the elapids and vipers independently stumbled on a secondary change, the suppression of the anterior region, that allowed the posterior fangs to move forward to make a more effective poison delivery system.

Story Reteller: PZ Meyers of Pharyngula
Evolving snake fangs
Evolutionary origin and development of snake fangs

How VENUS got her trap

2008-07-30T02:35:00.000-07:00

"The idea that plants – being the quintessence of peaceful
organisms standing at the basis of the food chain of life –
could themselves catch and eat animals, appeared so improbable to most botanists and other researchers that from the first descriptions in the fifteenth and sixteenth centuries
it took several hundred years for the carnivorous nature of these plants to be generally recognized ... The evolution of leaves with trap systems from noncarnivorous ones is mysterious, and there are no widely accepted hypotheses. Nachtwey concluded in 1959 concerning the origin of Utricularia’s trap that none of the contemporary evolutionary theories were able to answer these questions, and proposed that the answer might lie outside of the present scientific paradigms.

Story Researchers: Wolf-Ekkehard Lo¨nnig, and Heinz-Albert Becker, Max-Planck-Institute for Plant Breeding Research, Cologne, Germany
Source: Carnivorous plants

Story Researchers: Uncommon Descent
Source: Loennig and Becker on the origin of carnivorous plants

P.S. Since we have not yet found a story teller who has come up with even a slightly entertaining Darwinian Just So Story for the Venus Fly trap, we were forced to publish an article by two story researchers. Story Teller contributions are welcome. Love Dolly

How FISH learnt to grunt

2008-07-19T07:11:00.000-07:00

"Next time you're at a loud singles bar, thank a fish for inspiration." Here's why: When a male midshipman fish eyes a competitor swimming too close, he chases off the interloper with an audible grunt. To attract a mate, he hums loudly for hours on end. Now these cries have attracted researchers seeking to figure out whether noisy animals, from fish to mammals, have a common ancestor that gave them the ability to vocalize. Researchers studied the larvae of three closely related species of bony fish—the midshipman fish, Gulf toadfish and oyster toadfish—that make sounds by squeezing their swim bladders up to 200 times per second. They report in Science that the parts of the brain and spinal cord that control the rhythm of those muscles develop in a pattern similar to that of other vocalizing animals, which suggests a common origin. Of course, the instruments being played by these brain cells—swim bladders in fish; the larynx in mammals—probably evolved independently. Think of that next time you're listening to a tall fishing story.

Storyteller: Andrew H. Bass, Department of Neurobiology and Behavior, Cornell University,

Evolutionary Origins for Social Vocalization in a Vertebrate Hindbrain–Spinal Compartment
Grunting, humming fish joins ancient chorus

How BIRD learnt to sing

2008-07-12T06:11:00.000-07:00

The fastest muscles known lie within the throats of songbirds, according to new research on how birds vibrate their vocal cords. Superfast muscles were previously known only from the sound-producing organs of rattlesnakes, several fish and the ringdove. We now have shown that songbirds also evolved this extreme performance muscle type, suggesting these muscles -- once thought extraordinary -- are more common than previously believed."

Daniel Mennill, an avian biologist at the University of Windsor in Canada, noted that fieldwork has shown songbird vocalizations to be among the most precisely timed behaviors in the animal kingdom. "The synchronized duets and choruses of wrens, for example, are the most highly coordinated animal behaviors ever recorded," he said. "By having these extraordinary muscles, birds have a more precise control of their voice and can actively change the volume and frequency of their song faster than previously thought physically possible," Elemans says.

Storytellers: Coen Elemans, University of Utah
Superfast Vocal Muscles In Songbirds: Hundred Times Faster Than Blink Of An Eye

Song Function and the Evolution of Female Preferences: Why Birds Sing, Why Brains Matter

Story Research: Publication bias in the study of bird song

The Origin of Human Speech: an "all or nothing" jump!

How PLANT dressed up

2008-07-05T01:34:00.000-07:00

Angiospermae: They're all around us. Look out almost any window and you'll see hundreds of them - the grass, the trees, the scraggly little weeds that force their way up between pavers. Our lives are shaped by them. In fact, we would never exist without them. They feed us, clothe us, inspire us. But where did they come from? At one point, researchers thought they had a pretty good idea of the origins of flowering plants, but in the past two decades molecular data have cruelly conspired to make our understanding far more shaky than it once was. They may rule the planet now, but they might as well have come from outer space. Where to next?

"Insect-attracting strobili such as found in Bennettitales could have quite easily given rise to the first flowers. Developmental genetics has confirmed the theory put forward many years previously that petals and sepals represent modified leaves, and by affecting the expression of the genes involved it has proved possible to make leaves grow instead of petals, and petals grow instead of leaves (Goto et al., 2001). So while we have still not entirely solved what Darwin so overquotedly referred to as the 'abominable mystery', the answer has drawn tantalisingly close." The Origin of flowers

Storyteller: Christoper Taylor
Storyreteller: Larry Moran, Department of Biochemistry, University of Toronto

The Evolution of flowering plants

How FROG got her claws out

2008-06-26T00:35:00.000-07:00

Biologists at Harvard University have determined that some African frogs carry concealed weapons: When threatened, these species puncture their own skin with sharp bones in their toes, using the bones as claws capable of wounding predators.

"It's surprising enough to find a frog with claws," says Blackburn, a doctoral student in Harvard's Department of Organismic and Evolutionary Biology. "The fact that those claws work by cutting through the skin of the frogs' feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality."

"Most vertebrates do a much better job of keeping their skeletons inside," he adds.

Vertebrate claws are used in a variety of important behaviours and are typically composed of a keratinous sheath overlying the terminal phalanx of a digit. Keratinous claws, however, are rare in living amphibians; their microstructure and other features indicate that they probably originated independently from those in amniotes. Here we show that certain African frogs have a different type of claw, used in defence, that is unique in design among living vertebrates and lacks a keratinous covering.

Storytellers: David C. Blackburn, James Hanken, Farish A. Jenkins - Dept. Organismic and Evolutionary Biology Harvard University

When Threatened, A Few African Frogs Can Morph Toes Into Claws

How ADAM met STEVE

2008-06-20T07:17:00.000-07:00

An Italian research team claims that the evolutionary origin and maintenance of male homosexuality in human populations could be explained by a model of sexually antagonistic selection.

"Male homosexuality is difficult to explain under Darwinian evolutionary models, because carriers of genes predisposing towards male homosexuality would be likely to reproduce less than average, suggesting that alleles (variations of the same gene) influencing homosexuality should progressively disappear from a population.

The model show the interaction of male homosexuality with increased female fecundity (fruitfulness) within human populations, in a complex dynamic, resulting in the maintenance of male homosexuality at stable and relatively low frequencies, and highlighting the effects of heredity through the maternal line.

"Our findings provide new insights into male homosexuality in humans. In particular, they promote a focus shift in which homosexuality should not be viewed as a detrimental trait (due to the reduced male fecundity it entails, but, rather, should be considered within the wider evolutionary framework of a characteristic with gender-specific benefits, and which promotes female fecundity. This may well be the evolutionary origin of this genetic trait in human beings."

Storytellers: Andrea Camperio Ciani and Giovanni Zanzotto at the University of Padova and Paolo Cermelli at the University of Torino

Male Homosexuality Can Be Explained Through A Specific Model Of Darwinian Evolution, Study Shows

How HUMAN caught the joke

2008-06-16T08:50:00.000-07:00

The Pattern Recognition Theory of Humour by Alastair Clarke is an evolutionary and cognitive explanation of how and why an individual finds something funny. Effectively it explains that humour occurs when the brain recognizes a pattern that surprises it, and that this recognition is rewarded with the experience of the humorous response.” says Clarke.
Humour is not about comedy it is about a fundamental cognitive function. Clarke explains: “An ability to recognize patterns instantly and unconsciously has proved a fundamental weapon in the cognitive arsenal of human beings.” Recognising patterns enables us to quickly understand our environment and function effectively within it: language, which is unique to humans, is based on patterns.
Storyteller: Alastair Clarke
Humor Shown To Be Fundamental To Our Success As A Species

How BEE learned to dance

2008-06-12T02:38:00.000-07:00

ScienceDaily (Jun. 10, 2008) — Asian and European honeybees can learn to understand one another's dance languages despite having evolved different forms of communication, an international research team has shown for the first time.

The nine species of honeybees found worldwide separated about 30 to 50 million years ago, and subsequently developed different dance 'languages'. The content of the messages is the same, but the precise encoding of these languages differs between species.
Now researchers from Australia, China and Germany have discovered that the two most geographically distant bee species -- the European honeybee Apis mellifera and the Asian honeybee Apis cerana -- can share information and cooperate to exploit new food sources.
Storytellers: Dr Shenglu Chen and Songkun Su from Zhejiang University in China and Dr Jürgen Tautz from Würzburg University in Germany
Honeybee Dance Breaks Down Cultural Barrier

How KOALA got it backwards

2008-05-22T00:50:00.000-07:00

"Type 6 pouches (a bag with an opening oriented to the rear) are understandably linked with burrowing in wombats, bandicoots, and the marsupial mole, but are also found in the aquatic Chironectes. However, there is a ringer: the koala possesses a backwards-opening pouch, despite the fact that it is almost strictly arboreal (lives in trees) and certainly never burrows!

We are tempted to regard this instance of an inappropriate container for the neonate as an instance of maladaptive radiation, but perhaps it is just a palimpsest (a manuscript which has been re-used by scraping off the original text and writing over the top) of the koala's shared phylogenetic history with wombats. However, M. Renfree makes the interesting suggestion that the koala's Type 6 pouch may facilitate coprophagy (eating feces) by the young, which is necessary to develop the gut flora associated with digestion of Eucalyptus leaves.

Deep pouches evolved in arboreal or saltatory taxa; backward- oriented pouches arose in burrowing forms and an aquatic species, and were retained (perhaps to encourage coprophagy and transfer of intestinal flora) in the arboreal folivorous koala."

Storytellers: Thomas J. Givnish and Kenneth J. Sytsma
Molecular Evolution and Adaptive Radiation

Story Research : Geoffrey Simmons
Billions of Missing Links: Wombat Pouches

How SHRIMP saw the light

2008-05-15T07:12:00.000-07:00

Dr Sonja Kleinlogel and Professor Andrew White have shown that mantis shrimp not only have the ability to see colours from the ultraviolet through to the infrared, but have optimal polarisation vision -- a first for any animal and a capability that humanity has only achieved in the last decade using fast computer technology.

"It is this unique talent which presents a completely new concept of polarisation vision," Dr Kleinlogel continues. "There wouldn't be much point in only being able to see circular polarisation as it is extremely rare in nature.

"We doubt that circular polarisation is used exclusively as a secret shrimp sex signal! It makes more sense that mantis shrimp evolved both circular and linear polarisation receptors to work together so they can detect tiniest changes in any polarisation."

Prof. White notes, "Some of the animals they like to eat are transparent, and quite hard to see in sea-water - except they're packed full of polarising sugars - I suspect they light up like Christmas trees as far as these shrimp are concerned." "And of course," Dr Kleinlogel concludes, "they can still flirt with each other using fancy polarisation cues!"

Storytellers: Dr Kleinlogel, is based at the Max Planck Institute for Biophysics in Frankfurt

Weird Shrimp has astounding vision

How FROG lost her lungs

2008-04-10T09:50:00.000-07:00

A rare and primitive frog discovered in Borneo has no lungs and seems to have evolved backwards, scientists say. The animal apparently absorbs oxygen through its skin - meaning it has re-acquired a trait thought to have existed in animals millions of years ago. No other known frog breathes that way.

Biologist, David Bickford, said studying the animal could help shed light on how lungs evolved in the first place.

"The evolution of lunglessness in tetrapods (amphibians, reptiles, birds, and mammals) is exceedingly rare, previously known only from amphibians - two families of salamanders and a single species of caecilian (blindworm)," they wrote.

"Here we report the first case of complete lunglessness in a frog, Barbourula kalimantanensis, from the Indonesian portion of Borneo."

StoryTeller: David Bickford, National University of Singapore
Gasp! Scientists find first lungless frog

How HUMAN became promiscuous

2008-03-22T02:26:00.000-07:00

Evolutionary psychologists have suggested that men are more likely to have extramarital sex, partially due to the male urge to "spread genes" by broadcasting sperm. Both males and females, these scientists say, try to up their evolutionary progress by seeking out high-quality mates, albeit in different ways.

The committed partnership between a man and a woman evolved, some say, for the well-being of children.

"The human species has evolved to make commitments between males and females in regards to raising their offspring, so this is a bond," said Jane Lancaster.

"I don't think we are a monogamous animal," said Pepper Schwartz, "A really monogamous animal is a goose – which never mates again even if its mate is killed ... Monogamy is invented for order and investment – but not necessarily because it's 'natural.'"

Storyteller: Jane Lancaster, evolutionary anthropologist, University of New Mexico.
Storyteller: Professor of sociology at the University of Washington in Seattle.
Are Humans Meant to be Monogamous?

How HOBBIT became human

2008-03-15T08:51:00.000-07:00

Researchers now believe that the fossils' little primordial features, which other scientists previously reckoned belonged to a more primitive species, could in fact be humans affected by a well known and documented medical condition.

They added that, "this extreme form of cretinism is the result of severe iodine deficiency in pregnancy in combination with a number of other environmental factors."

Although majority of the people who've taken a glance at the fossils have been trying to understand it from an evolutionary perspective, these two propose that this was an "environmentally caused problem."

Story Untellers: Dr Peter Obendorf and Dr Ben Kefford, from RMIT's School of Applied Sciences
Hobbits declared human

Storytellers : Friends of Darwin Web Site
Let's not call them Hobbits

How ANT learnt to cheat

2008-03-15T07:59:00.000-07:00

Social groups are vulnerable to cheating because the reproductive interests of group members are rarely identical. All cooperative systems are therefore predicted to involve a mix of cooperative and cheating genotypes, with the frequency of the latter being constrained by the suppressive abilities of the former. The most significant potential conflict in social insect colonies is over which individuals become reproductive queens rather than sterile workers. Here, we show that one-fifth of leaf-cutting ant patrilines cheat their nestmates by biasing their larval development toward becoming queens rather than workers. Just as evolutionary theory predicts... The rarity of royal cheats is best explained as an evolutionary strategy to avoid suppression by cooperative genotypes, the efficiency of which is frequency-dependent. The results demonstrate that cheating can be widespread in even the most cooperative of societies and illustrate that identical principles govern social evolution in highly diverse systems.

Storyteller: Dr Bill Hughes from Leeds’ Faculty of Biological Sciences
Genetic royal cheats in leaf-cutting ant societies
Royal Corruption Is Rife In The Ant World

How HUMAN got hiccups

2008-02-25T10:35:00.000-08:00

Our tendency to develop hiccups is another influence of our past. There are two issues to think about. The first is what causes the spasm of nerves that initiates the hiccup. The second is what controls that distinctive hic, the abrupt inhalation–glottis closure. The nerve spasm is a product of our fish history, while the hic is an outcome of the history we share with animals such as tadpoles.

The problem is that the brain stem originally controlled breathing in fish; it has been jerry-rigged to work in mammals. Sharks and bony fish all have a portion of the brain stem that regulates the rhythmic firing of muscles in the throat and around the gills. The nerves that control these areas all originate in a well-defined portion of the brain stem. We can even see this nerve arrangement in some of the most primitive fish in the fossil record. Ancient ostracoderms, from rocks over 400 million years old, preserve casts of the brain and cranial nerves. Just as in living fish, the nerves that control breathing extend from the brain stem.

Story-reteller : PvM of Panda's Thumb
Your Inner Fish - Hiccups
Fish out of water

How BAT learned to Glide

2008-02-18T23:27:00.000-08:00

A fossil discovered in Wyoming seems more like a glider than a flier. Charles Darwin worried about bats, wondering whether his scientific successors would ever figure out how they evolved.

Until now, all fossil bats looked just like today's bats, says paleontologist Kevin Seymour of the Royal Ontario Museum. Last week, he and colleagues announced a missing bat link - a 52-million-year-old skeleton pulled from an outcrop in southern Wyoming. The creature had a shorter wingspan and longer legs than other bats, more similar to the tree-climbing or scurrying mammals that must have been its ancestors.
Seymour said this new transitional bat probably evolved from some clawed, tree-climbing animal that learned to glide. Gliding is a surprisingly common adaptation, he said. There are gliding lemurs, gliding frogs, and even gliding lizards. Eventually some of those proto-bats developed the ability to flutter as well as glide - a pattern seen today in the mouse-tailed bat.

Storyteller : Paleontologist Kevin Seymour of the Royal Ontario Museum.

Found: An ancient bat in transition

How GECKO got Stuck (and unstuck)

2008-02-12T09:12:00.000-08:00

"Unlike most creatures, geckos don't use sticky secretions to help them hang on, it's all due to the structure of their amazing skin," says professor Anthony Russell, one of the world's leading experts on the gecko family of lizards. "Figuring out how they are able to run across ceilings and walk up windows is remarkably complex but it is getting a lot of attention because of the possible technology it could yield."

Russell says learning from how species are designed by nature to deal with environmental challenges provides key lessons for human innovations."This nano-technology has been around for over 50 million years and we are only just beginning to understand how it works," he said.

Storyteller: Anthony (Tony) Russell - University of Calgary professor of zoology

Sticky Questions Tackled In Gecko Research

How ANT became a ripe, red berry

2008-01-24T04:56:00.001-08:00

ScienceDaily (Jan. 21, 2008) — A newly discovered parasite so dramatically transforms its host, an ant, that the ant comes to resemble a juicy red berry, ripe for picking, according to a report accepted for publication in The American Naturalist. This is the first example of fruit mimicry caused by a parasite, the co-authors say.

Birds apparently are merely a way to spread the parasite's eggs more broadly, since the eggs pass directly through into the feces. Ants become infected when they feed to ant larvae the bird feces containing parasite eggs.

"It's just crazy that something as dumb as a nematode can manipulate its host's exterior morphology and behavior in ways sufficient to convince a clever bird to facilitate transmission of the nematode," says Robert Dudley, a professor of integrative biology at the University of California, Berkeley.

"This is a really great example of the kinds of complex host-parasite interactions that can co-evolve, and also of the role of serendipity in tropical biology," Dudley said.

Story Teller: Robert Dudley, a professor of integrative biology at the University of California, Berkeley.

Ant Parasite Turns Host Into Ripe Red Berry

How Bambi evolved into Moby-Dick

2008-01-03T06:04:00.000-08:00

A small deer-like animal that evaded predators by hiding underwater may have evolved into today's whales.

The landmark finding represents a long-sought "missing link" in the 10m-year journey that saw ancient land mammals evolve into modern cetaceans, a group that includes whales, dolphins and porpoises.

Scientists have long known that whales are mammals whose ancient ancestors walked on land, but only in the past 15 years have they unearthed fossils that shed light on the creatures' dramatic evolutionary history. The latest discovery, named Indohyus, is the first whale ancestor known to have lived on land.

A near-complete skeleton of the animal was constructed, close in size to a domestic cat, dating from 48m years ago.

Storyteller : Hans Thewissen at the Northeastern Ohio Universities College of Medicine
How Bambi evolved into Mobi-Dick

Story Research : How Bambi gave rise to Mobi-Dick.

How Fish found his legs

2007-12-01T13:03:00.000-08:00

"In 2004, a field crew digging in the Canadian Arctic unearthed the fossil remains of a half-fish, half-amphibian that would all but confirm paleontologists' theories about how land-dwelling tetrapods (four-limbed animals, including us) evolved from their fish ancestors. The animal was a so-called lobe-finned fish that lived about 375 million years ago. Named Tiktaalik rosae by its discoverers, it is a classic example of a transitional form, one that bridges the evolutionary gap between two quite different types of animal." Rima Chaddha

Storyteller: NOVA Fossil Evidence
Story Research : Uncommon Descent
Possible Link Between Fish and Land Animals Discovered

How Appendix got a job

2007-10-23T05:17:00.000-07:00

WASHINGTON - Some scientists think they have figured out the real job of the troublesome and seemingly useless appendix: It produces and protects good germs for your gut.

That's the theory from surgeons and immunologists at Duke University Medical School, published online in a scientific journal this week.

For generations, the appendix has been dismissed as superfluous. Doctors figured it had no function. Surgeons removed them routinely. People live fine without them.

And, when infected, the appendix can turn deadly. It gets inflamed quickly, and some people die if it isn't removed in time. Two years ago, 321,000 Americans were hospitalized with appendicitis, according to the Centers for Disease Control and Prevention.

The function of the appendix seems related to the large amount of bacteria populating the human digestive system, according to the study in the Journal of Theoretical Biology. There are more bacteria than human cells in the typical body. Most of it is good and helps digest food.

Storyunteller: Surgery professor Bill Parker, Duke University Medical School
Appendix is a refuge for good germs, study says
Story research: David Tyler
The human appendix - from rags to riches

How coelacanth couldnt (walk)

2007-09-30T09:25:00.001-07:00

Though he may have only been angling for dinner, the Indonesian fisher who caught a rare coelacanth

has instead snagged a barrage of worldwide media attention.

Scientists were shocked when a coelacanth (pronounced SEE-la-kanth) was found off Africa's coast in 1938. They had believed the fish went extinct 65 million years ago, as did a related lineage of prehistoric fishes.
The fish has been a source of fascination ever since. Several other coelacanths have been caught in recent decades, including another in the species-rich waters of Sulawesi in 1998.

Storyunteller: National Geographic, May 22, 2007

http://news.nationalgeographic.com/news/2007/05/070522-coel

How CHIMPANZEE got so kind

2007-06-28T09:33:00.000-07:00

Chimpanzees have shown they can help strangers at personal cost without apparent expectation of personal gain, a level of selfless behavior often claimed as unique to humans.
These new findings could shed light on the evolution of such altruism, researchers said.
Scientists think altruism evolved to help either kin or those willing and able of returning the favor — to help either one's genetic heritage or oneself. Humans, on the other hand, occasionally help strangers without apparent benefit for themselves, sometimes at great cost.

There is a biological predisposition to altruistic tendencies that we share with our common ancestor, and culture cultivates rather than implants the roots of altruism in the human psyche from primordial forms to more mature ones," Warneken told LiveScience.

Storyteller: Felix Warneken psychologist, Max Planck Institute for Evolutionary Anthropology at Leipzig, Germany.

How JUNK DNA became GOS

2007-06-20T12:49:00.000-07:00

THE first concerted effort to understand the inner workings of the DNA molecule is overturning a host of long-held assumptions about the nature of genes and their role in human health and evolution. The new perspective reveals DNA to be a dauntingly complex operating system (GOS*) that processes many more kinds of information than previously appreciated.

"There now appear to be thousands of places in the genome that were long thought to be useless or meaningless, but which we now see to have a functional role," ENCODE researcher Thomas Tullius of Boston University told the Boston Globe. "But we don't really understand what that role is."

"Most of the time, the human genome is operating on the 'first and second floor,' with 5 percent of the genome doing what needs to be done on a daily basis," Francis Collins, director of the National Human Genome Research Institute said at the news conference. "But over evolutionary time, a much larger part of the genome, the stuff in the attic, becomes important. It's waiting for natural selection to call for it."

Storyunteller: ENCODE researcher Thomas Tullius of Boston University
New findings challenge beliefs about DNA
Intricate Toiling Found In Nooks of DNA Once Believed to Stand Idle
Wikapedia - What is Junk DNA?

Story Research: Casey Luskin, Discovery Institute
Intelligent Design and the Death of the "Junk-DNA" Neo-Darwinian Paradigm

* Inserted (God's operating System)

How SCARAB got his Armour

2007-05-27T04:56:00.000-07:00

These animals have intense mating competitions in which the males guard their mates to prevent them from breeding with competitors, and they have evolved extravagant weapons for use in battles between males. They have long horns that they use for blocking tunnels to underground dens and for wrestling with competitors, and different species have followed different strategies. Some have a horn at the front of the head and look rhinocerous-like; others sprout a pair of horns, like those of a triceratops, at the back of the head; still others have a long protuberance from their thorax that can make up as much of 40 percent of their body length.

The competition between developing weapons and testes is the most obvious aspect of the evolution of these beetles, but the quieter underlying competition between reliability/canalization and flexibility/plasticity may well be the more significant force in evolution: It constrains the range of morphology that is possible in development.

Storyteller: PZ Myers, professor at the University of Minnesota

http://www.seedmagazine.com/news/2007/05/on_extravagant_proportions.php?page=1

How NATURE got "so clever"

2007-05-08T09:02:00.000-07:00

It is an old question: how does light make its way through all the retinal layers to finally strike the light sensitive cells at the back of the eye? A group of researchers at the Paul-Flechsig-Institute of Brain Research, Universität Leipzig in Germany, thinks it has the answer. They have demonstrated that light is collected and funnelled through long cells called Müller cells. These work almost exactly like a fibre optic plate: a "zero-length window" that optical engineers can use to transmit an image without using a lens.

"Nature is so clever," Reichenbach says. "This means there is enough room in the eye for all the neurons and synapses and so on, but still the müller cells can capture and transmit as much light as possible."

Storyteller: Andreas Reichenbach, Universität Leipzig in Germany

http://www.theregister.co.uk/2007/05/01/eye_eye/

Storyteller Master: Ian Musgrave, Pandas Thumb

http://www.pandasthumb.org/archives/2006/11/denton_vs_squid.html

Story research: The vertebrate eye does not have a compromised design

How HUMAN lost her gills

2007-05-07T22:44:00.000-07:00

'The parathyroid gland and the gills of fish are related structures and likely share a common evolutionary history,' said Professor Graham. 'Our work will have great resonance to all those people who have seen Haeckels' pictures, which show that we all go through a fish stage in our development. This new research suggests that in fact, our gills are still sitting in our throats - disguised as our parathyroid glands.'

Writing in the latest edition of Proceedings of the National Academy of Sciences, Professor Anthony Graham and Dr Masataka Okabe suggest that the gills of ancestral marine creatures, which were used to regulate calcium levels, were internalised rather than lost when land-living, four-limbed animals - the tetrapods - evolved.

Storyteller: Anthony Graham, professor of Developmental Biology at the MRC Centre for Developmental Neurobiology, King's College London

http://www.medicalnewstoday.com/medicalnews.php?newsid=17415

Story Research: Haeckel's Embryos & Evolution

How DUCK got the twist

2007-05-03T11:22:00.002-07:00

SYDNEY: Female ducks have evolved "maze-like" genitals with many twists, pouches and dead ends, in a bid to prevent rape and retain control of who fathers their offspring – while male ducks have evolved equally convoluted penises to keep up.
Patricia Brennan, an American reproductive biologist at Yale University in Connecticut, found that some ducks and geese have co-evolved elaborate genitals in an "evolutionary arms race" between the sexes.
Ducks, especially mallards, are one of the few species of birds in which males will often rape females, in a violent act which can result in injuries or death by drowning. The females fight back by preventing successful fertilisation, said Brennan. In fact, of the 40 per cent of matings which are a result of forced copulations, only around four per cent are successful.

Storyteller: Patricia Brennan, Reproductive biologist, Yale University, Connecticut.

http://www.cosmosmagazine.com/node/1277

Coevolution of Male and Female Genital Morphology in Waterfowl

How JUNK DNA became respectable

2007-04-27T11:35:00.000-07:00

Science Daily — Large swaths of garbled human DNA once dismissed as junk appear to contain some valuable sections, according to a new study by researchers at the Stanford University School of Medicine and the University of California-Santa Cruz. The scientists propose that this redeemed DNA plays a role in controlling when genes turn on and off.

Gill Bejerano, PhD, assistant professor of developmental biology and of computer science at Stanford, found more than 10,000 nearly identical genetic snippets dotting the human chromosomes. Many of those snippets were located in gene-free chromosomal expanses once described by geneticists as "gene deserts." These sections are, in fact, so clogged with useful DNA bits - including the ones Bejerano and his colleagues describe - that they've been renamed "regulatory jungles."

Story unTeller: Gill Bejerano, PhD, assistant professor, Stanford
http://www.sciencedaily.com/releases/2007/04/070423185538.htm
and
http://www.sciencedaily.com/releases/2007/06/070615091210.htm

Story Research: Junk DNA not so "junkie"

How FLOWER got her gown

2007-04-27T09:18:00.000-07:00

The varying shapes of flowers found in tropical forests, from broadly blooming to delicately narrow, may have to do with what has stuck its nose in there to pollinate in past evolutionary eras.
Different species of birds and bats may have encouraged flowers to evolve to fit the shape of their snouts or beaks, new findings suggest.
Flowers seem to respond to whatever is available and doing the best job of spreading pollen, said study leader Nathan Muchhala, a University of Miami biologist. Birds and bats have also changed their body shapes over time to adapt to available food sources and flower and plant shapes, but flowers have done so more aggressively, he said.

"Basically, the flowers are making an evolutionary decision," he told LiveScience. "Organisms can specialize in something (like having wide or narrow openings), but they have to make the tradeoff to be good at one or the other. This is a common misconception—that is, that each flower has its bat/bird specialist, and they are tightly interdependent, the one exception is a bat with an extremely long tongue (140 percent of body length!) from Ecuador—a flower with a matching tube length is exclusively specialized to this bat," he said.

Storyteller: Nathan Muchhala, a University of Miami biologist.

http://www.msnbc.msn.com/id/18279819/

How HUMAN got his NERVE

2007-04-21T00:37:00.000-07:00

"The origin of brain lies in a worm! Researchers discover that the centralised nervous system of vertebrates is much older than expected. Vertebrates, insects and worms evolved from the same ancestor, but their central nervous systems are different and were thought to have evolved only after their lineages had split during evolution. While vertebrates have a nervous system in the shape of a spinal cord running along their backs, insects and annelid worms like the earthworm have a rope-ladder-like chain of nerve cell clusters on their belly side.

"Such a complex arrangement could not have been invented twice throughout evolution, it must be the same system," adds Gáspár Jékely, a researcher from Arendt's lab, who contributed essentially to the study. "It looks like Platynereis and vertebrates have inherited the organisation of their central nervous systems from their remote common ancestors."

".... and vertebrates have turned themselves upside down throughout the course of evolution.

Storyteller: Detlev Arendt and his group study at EMBL
http://www.huliq.com/19209/the-origin-of-brain-lies-in-a-worm

How HOBBIT got his name

2007-04-19T23:39:00.000-07:00

A study released today backs up evidence that Homo floresiensis was a dwarf race that may have evolved from our own species through a natural evolutionary tendency for island species to get smaller.

The tiny hominids - dubbed after the diminutive hobbits imagined by J.R.R. Tolkien - were found on the Indonesian island of Flores in 2003, measuring just a metre tall, lived around 18,000 to 80,000 years ago and appear to have been skillful toolmakers. A separate species of human that descended from the extinct Homo erectus, who are also presumed to be the ancestors of modern man.

Evolutionary zoologists at Imperial College in London, U.K., argue that the hobbits could easily have evolved from a larger human species, such as ourselves, via a well-recognised evolutionary tendency, called the 'island rule'. Because food on a small island is limited, smaller species out-compete bigger species.

Storytellers: Dr Lindell Bromham, Department of Zoology and Entomology, University of Queensland and Marcel Cardillo, Imperial College, London.

Hobbit hominids lived the island life

Story Researchers : Dr Peter Obendorf and Dr Ben Kefford, from RMIT's School of Applied Sciences

Hobbits declared human

How PANDA got his thumb

2007-04-12T13:36:00.000-07:00

Stephen Jay Gould was amazed by the Panda's dexterity. "They held the stalks of bamboo in their paws and stripped off the leaves by passing the stalks between an apparently flexible thumb and the remaining fingers. But the thumb is not a finger at all. It is made from a wrist bone and equipped with muscles to sustain its agility.

If a man were to make a machine for some special purpose, but were to use old wheels. springs, and pulleys, only slightly altered, the whole machine, with all its parts, might be said to be specially contrived for that purpose.

We may not be flattered by the metaphor of refurbished wheels and pulleys, but consider how well we work. Nature is, in biologist Francois Jacob's words, an excellent tinkerer, not a divine artificer. And who shall sit in judgment between these exemplary skills?"

Storyteller: Stephen Jay Gould, Harvard University.
The Panda's Thumb by Stephen Jay Gould

How CHAMELEON got crosseyed

2007-04-08T13:22:00.000-07:00

Both sandlance and chameleon strikes are rapid (being completed in 100–200 msec) and error-free, never missing the prey under ordinary circumstances. To an unaided human eye, the strikes of a sandlance, from a camouflaged position in the sand to zooplankton moving in the water column, look quite similar to the dart of the chameleon’s tongue. Both the sandlance and the chameleon have highly independent eye movements

Predation on chameleons and sandlance is only rarely observed in the wild. Nevertheless, we feel that visually directed predation, both by and on the sandlance and the chameleon, provide the most likely context in which to understand the selection pressures that have brought about this remarkable convergence. We think that the selection pressure operates in two directions. Firstly, to provide an eye movement regime and an optical strategy that can localise and acquire prey accurately for a fast strike. Secondly, to reduce the conspicuousness of the efforts being made by the visual and oculomotor systems to localise prey. Therefore, the skin covering the eyes in both the sandlance and the chameleon even further reduces the eye’s conspicuousness. (sandlance videoclip : I spy with my little ..)

Storyteller: JD Pettigrew, Department of Physiology and Pharmacology, University of Queensland, Brisbane.
Convergence of specialised behaviour, eye movements and visual optics in the sandlance (Teleostei) and the chameleon (Reptilia)

Story Research: Convergent Evolution Examples- Ecological Equivalents
Marsupials and Placentals: a case of front-loaded, pre-programmed, designed evolution?

How FROG got her poison

2007-04-07T00:49:00.000-07:00

The golden poison frog has enough venom in its skin to kill 12 people.
Why else would a creature coveted by everything from snakes and birds to Jacques Pépin evolve an extravagantly colored skin, except to warn any would-be predators of bitter toxins embedded therein?
Now it turns out that it is no mean feat for a frog to earn its mean feet, and that one of the surest routes to optimal toxicity is through a highly specialized form of ant eating.

Writing in the current issue of The Proceedings of the National Academy of Sciences, researchers report that poison frogs in Africa and the Neotropics of Central and South America appear to have converged on the same difficult method of harvesting the toxic chemicals they need to defend themselves against predators. Both the famed poison-dart frogs of the New World and the Mantella poison frogs of Madagascar dine largely though not exclusively on ants, and many of those ants, the researchers have determined, contain toxic chemicals called alkaloids.

Through entirely independent pathways, it seems, the two unrelated groups of frogs evolved a similar capacity to store, or sequester, the ingested alkaloids in their skin sacs without being harmed by the pungent substances themselves. And once the unrelated amphibian clans had succeeded in caching the ant bane in their glands, they autonomously evolved bright coloration to broadcast to potential frog-eaters their possession of distasteful alkaloids. The evolution of chemical protection and concomitant advertising gave the poison frogs a considerable leg up on the competition. Whereas most frogs dare only emerge at night to feed and will skitter for cover at the slightest breeze, a majority of poison frogs are diurnal, brazenly hopping around the sunlit forest floor like scattered gems on pogo sticks.

Storyteller: Natalie Angier, science journalist for the New York Times.
http://chemicalecology.psu.edu/news/Frogs.pdf

How LIFE began

2007-03-31T03:58:00.000-07:00

“When the earth formed some 4.6 billion years ago, it was a lifeless, inhospitable place. A billion years later it was teeming with organisms resembling blue-green algae. How did they get there? How, in short, did life begin? This long-standing question continues to generate fascinating conjectures and ingenious experiments, many of which center on the possibility that the advent of self-replicating RNA was a critical milestone on the road to life. “

Leslie Orgel of the research professor at the Salk Institute for Biological Studies in San Diego explains ...

“….all these problems are worrisome, but they do not completely rule out the possibility that RNA was initially synthesized and replicated by relatively uncomplicated processes. Perhaps minerals did indeed catalyze both the synthesis of properly structured nucleotides and their polymerization to a random family of oligonucleotides. Then copying without replication would have produced a pair of complementary strands. If, as Szostak has posited, one of the strands happened to be a ribozyme that could copy its complement and thus duplicate itself, the conditions needed for exponential replication of the two strands would have been established. This scenario is certainly very optimistic, but it could be correct. “

Storyteller: Leslie E. Orgel, senior fellow and research professor at the Salk Institute for Biological Studies in San Diego
http://www.geocities.com/capecanaveral/lab/2948/orgel.html

Story Research: Why is origin of life such a difficult problem?

How PLATYPUS stayed the same

2007-03-21T06:48:00.000-07:00

The duck-billed platypus takes true honors although the species has only been around about 100,000 years. This creature's basic design, however, has endured for about 110 million years — one of the longest-lived successful body plans, say Ondine Evans and Anne Musser of The Australian Museum The champs with this good survival strategy are the egg-laying monotremes, a group that evolved about 110 million years ago in the mid Cretaceous period. (See chart.)

The duckbill platypus is a current member of the ancient monotreme group. Indeed she harkens back to an even earlier design — that of the mammal-like reptiles that predated the dinosaurs by 80 million years and lived in the late Carboniferous period, about 300 million years ago.

The platypus is an unusual mammal. She lays eggs. She waddles like a reptile with legs to the side rather underneath her body. She has a single orifice for all systems: urinary, excretory, and reproductive. That's the origin of the word "monotreme": Mono – Greek for "one," trema – Greek for "hole." A simple, successful design.

Storytellers: Ondine Evans and Anne Musser of The Australian Museum
http://www.usatoday.com/tech/columnist/aprilholladay/2005-01-14-wonderquest_x.htm
Story Reteller: April Holladay, Wonderquest, USA today

Story Research: Duck-billed platypus: Primitive or not?
11/23/07 -The "implausible" platypus continues to surprise

How the BACTERIUM got her Flagellum

2007-03-20T10:33:00.000-07:00

The bacterial flagellum is a complex molecular system with multiple components required for functional motility. Such systems are sometimes proposed as puzzles for evolutionary theory on the assumption that selection would have no function to act on until all components are in place. However, published attempts to explain flagellar origins suffer from vagueness and are inconsistent with recent discoveries and the constraints imposed by Brownian motion. A new model is proposed based on two major arguments. First that even very crude motility can be beneficial for large bacteria. Second, homologies between flagellar and nonflagellar proteins suggest ancestral systems with functions other than motility. Therefore, like the eye contemplated by Darwin, careful analysis shows that there are no major obstacles to gradual evolution of the flagellum.

Storyteller: Nicholas Matzke, Public Information Project Director, M.A., Geography, U.C. Santa BarbaraB.S., Biology, B.S., Chemistry, Valparaiso University

http://www.talkdesign.org/faqs/flagellum.html

Story Research: Darwinism gone wild

How BAT got his wings

2007-03-20T09:46:00.000-07:00

Karen Sears, at the University of Colorado Health Sciences Center in Denver, has discovered why intermediate forms may be missing in the fossil record.

A change to a single gene allowed bats to grow wings and take to the air, a development that may explain why bats appeared so suddenly in the fossil record some 50 million years ago.
Bats have been an evolutionary enigma. That’s because the oldest fossil bats look remarkably like modern ones, each having wings formed from membranes stretched between long fingers, and ear structures designed for echolocation. No fossils of an animal intermediate between bats and their non-flying mammal ancestors have been found. We’ve never had an adequate explanation” for the sudden appearance of bats, Nancy Simmons of the American Museum of Natural History in New York told New Scientist. “This sounds like a remarkable discovery.”
The lack of transitional forms has also led to speculation about the origin of bats, with some believing that primates are their closest relatives. Genetic studies now show they are closest to ferungulates, which include horses and pigs, or to the shrews and moles.

Storyteller : Karen Sears, at the University of Colorado Health Sciences Center in Denver
http://www.newscientist.com/article.ns?id=dn6647

Story Reteller : Dave Thomas of Panda's thumb http://www.pandasthumb.org/archives/2004/11/a_quantum_leap.html

Storyteller 2 : Jennifer S. Holland, National geograghic
Sixty million years ago, on a planet crawling with mammals, one tree dweller rose above the crowd on paper-thin wings

How SHARK got his jaws

2007-03-17T07:31:00.000-07:00

Paleontologists believed that, over millions of years, lamprey-like creatures evolved into jawed, bony fish. Picture a leech longer than your forearm with a rasp-like mouth that flares open at the end of its body. It turns out lampreys, long thought to have taken a different evolutionary road than almost all other backboned animals, may not be so different after all, especially in terms of the genetics that govern their skeletal development, according to findings to be published online this week in the Proceedings of the National Academy of Sciences. "The lamprey is like the great-, great-, great-aunt descended from the earliest backboned animal," said Michael Miyamoto, Ph.D., a professor and associate chairman of UF's zoology department.

Storyteller: Michael Miyamoto, Ph.D., a professor and associate chairman of UF's zoology department.

http://www.underwatertimes.com/news.php?article_id=53910782640

See also: How SALAMANDER found his feet

How SALAMANDER found his legs

2007-03-16T23:25:00.000-07:00

The first animal to crawl onto land from the ocean probably looked a bit like today's salamander and researchers have wondered how it was able to switch from swimming to walking. Now, European scientists have built a robot with a primitive electric nervous system that they say mimics that change in motion.

So they first designed a basic nervous system modeled on that of the lamprey, a long, primitive eel-like fish. Then that design was modified to show how it could evolve into a nervous system that also could control walking.

Its swimming motion uses undulations like the lamprey, while on land the robot uses a slow stepping gait with diagonally opposed limbs moving together while the body forms an S-shape.

"We were trying to understand what really happened during the transition from primitive fishes to amphibians, like the salamander," said "We were trying to understand what really happened during the transition from primitive fishes to amphibians, like the salamander," said physicist Auke Ijspeert.

Storyteller: Auke Ijspeert, a physicist of the Swiss Federal Institute of Technology in Lausanne.

Story reteller: Jeanna Bryner http://www.foxnews.com/story/0,2933,257938,00.html

Story reteller: Randolph E. Schmid http://www.enn.com/today.html?id=12363

How Beetle got the bomb

2007-03-09T09:31:00.000-08:00

"The bombardier beetle shoots its enemies with a boiling hot chemical weapon that evolved millions of years before its modern analog in human technology: automatic valves in the pulse-jet engine of the German V-1 flying bomb the terrifying 'buzz bomb' of World War II that rained indiscriminate death on England."

Three Cornell University biologists, working with the late Professor Harold (Doc) Edgerton of MIT, have discovered this surprising anticipation of technology by nature. Writing in a recent issue of Science, Cornell scientists Jeffrey Dean, Associate Professor Daniel J. Aneshansley, and Professor Thomas Eisner explain their remarkable discovery, which required co-author Doc Edgerton's high-speed photography to catch the beetle in action.

Dr. Eisner explained the cycle that apparently occurs within the beetle an average of about 500 times per second: "The bombardier beetle uses what is essentially a binary weapon. It stores the two ingredients of an explosive chemical process hydroquinones and hydrogen peroxide in a pair of reservoirs, and the catalysts for the reaction...in [another] pair of reaction chambers."When the beetle is disturbed, muscles around the reservoirs contract just enough to force a little of the hydroquinones and hydrogen peroxide through one-way valves that are normally closed. As the catalysts start the reaction, heat and pressure of the oxygen [liberated from the hydrogen peroxide] quickly close the valves. Pressure continues to build until the reaction chambers vent through the tip of the abdomen with a high velocity pulse of quinones." Then the reaction chamber pressure drops enough to reopen the biological valves, and the process repeats itself automatically at a rate hundreds of times per second.

Storytellers : Cornell scientists Jeffrey Dean, Associate Professor Daniel J. Aneshansley, and Professor Thomas Eisner

Story reteller : Roger Segelken
Doc's Parting Shot; A Shooting Beetle

See also:
Insect Inspiration

Story reteller: T. Ryan Gregory, Evolutionary biologist , University of Guelph, Canada.
Evolution of the Bombardier Beetle
and Bombardier Beetles and Climbing Mount Improbable

How human got so brainy

2007-03-03T22:36:00.000-08:00

Forget the textbook story about tool use and language sparking the dramatic evolutionary growth of the human brain. Instead, imagine ancient hominid children chasing frogs. Not for fun, but for food. According to Dr. Stephen Cunnane it was a rich and secure shore-based diet that fueled and provided the essential nutrients to make our brains what they are today. Controversially, according to Dr. Cunnane our initial brain boost didn't happen by adaptation, but by exaptation, or chance."Anthropologists and evolutionary biologists usually point to things like the rise of language and tool making to explain the massive expansion of early hominid brains. But this is a Catch-22. Something had to start the process of brain expansion and I think it was early humans eating clams, frogs, bird eggs and fish from shoreline environments. This is what created the necessary physiological conditions for explosive brain growth," says Dr. Cunnane, a metabolic physiologist at the University of Sherbrooke in Sherbrooke, Quebec.

Storyteller: Dr Cunnane, University of Sherbrooke in Sherbrooke, Quebec.
http://evolutionlist.blogspot.com/2006/02/theres-something-fishy-about-human.html
Reteller : Allen MacNeill, Biology and evolution Teacher at Cornell University in Ithaca, NY.

How Woodpecker used his head

2007-03-02T09:09:00.000-08:00

According to Ivan R Schwab of the University of California, to equip the bird for its ecological niche, evolution has provided the woodpecker with a thick bony skull with relatively spongy bone, especially at the occiput, and cartilage at the base of the mandible to partially cushion the incessant blows. This woodpecker has evolved several unique mechanisms to prevent brain damage, retinal haemorrhages, and retinal detachment. The woodpecker has other unique adaptations that deserve recognition and may contribute to the protection from intracranial injuries. The tongue is most unusual as it originates on the dorsum of the maxilla, passes through the right nostril, between the eyes, divides into two, arches over the superior portion of the skull and around the occiput passing on either side of the neck, coming forward through the lower mandible, and uniting into a single tongue in the oropharyngeal cavity. The muscles encase the bony hyoid throughout this muscular course into the oropharynx and are additionally secured in the floor of the mouth creating an apparatus that allows for extraordinary protrusion of the tongue of up to 4 inches beyond the tip of the bill! These musculotendinous bands create a curious sling-like structure that probably functions as an isometric shock absorber if contracted before each strike. This sling would also serve to distribute the potential shearing forces. Such length is useful for penetrating insect nests beneath the bark of trees. The sharp tongue (literally) is coated with sticky saliva for smaller insects such as ants and has backward pointing barbs that are useful in impaling larger insects and grubs. For added emphasis, the tongue is equipped with excellent tactile abilities to allow for recognition of smaller insects, such as ants. The chisel tipped mandibles are constructed of individual fused plates of keratin called rhamphotheca, and the longitudinal trabeculae are reinforced with calcium.

Storyteller : Ivan R Schwab University of California, Davis, Department of Ophthalmology

http://bjo.bmj.com/cgi/content/full/86/8/843

How Angler fish got his tackle

2007-03-01T13:14:00.000-08:00

An anglerfish, looking for all the world like a rock or shell, waves before its maw a piece of bait resembling small fish found in this region. The bait, which is part of the anglerfish's body, has fins, a tail, and black spots for eyes. The waving about of the bait attracts predatory fish close enough for the anglerfish to snap them up. The authors surmise that the anglerfish evolved this realistic bait (and rod and reel) in order to save energy in acquiring food.

Storyteller: Pietsch, Theodore W., and Grobecker, David B.; "The Complete Angler: Aggressive Mimicry in an Antennariid Anglerfish," Science, 201:369

Acknowledgements: http://www.science-frontiers.com/sf005/sf005p09.htm

How Mantis copied orchid

2007-02-24T09:09:00.000-08:00

It sits quietly on a flower and waits for its preyIts white pink pattern matches common flowers in tropical rainforests but is not similar to any flower in particular.There is a small green band across the thorax, useful decoy to break up the mantid outline in and making it resemble two separate flowers.Between the eyes there is a small horn, simulating a flower reproductive apparatus.There is a dark spot in the last part of the abdomen, near the anus which attracts small flies, into mistaking the spot for another fly foraging on flower.There are many longitudinal brown stripes along the upper side of the abdomen. These are very similar to orchids “honey guides” and are directed toward the mantis thorax. Some insects are attracted this way but usually dorsal abdomen is not visible in rest position.When moving slowly it uses a swinging movement, similar to a plant moved by a breeze.

The Discovery Channel describes the orchid as one of the “marvels of nature” and says for the mantis’ camouflage: “When the survival of the species is at stake it is only normal for this kind of disguise to evolve.”

Storyteller : The Discovery Channel

How Squirrel secured his nuts

2007-02-21T11:00:00.000-08:00

A team of scientists, led by Dr. Stan Boutin from the U of A’s Faculty of Science, has discovered that red squirrels are able to counter the trees’ "swamp and starve" strategy of boom and bust seed production by producing an extra litter of babies in anticipation of a lush season of tree seeds. In an evolutionary game of tug-of-war, red squirrels have gained the upper hand over the cunning spruce trees, says new University of Alberta research that suggests the clever animals are staying one step ahead of its food source.

In a paper published in "Science," Boutin and his international team of researchers, describe how they have studied the relationship between the American and Eurasian red squirrel and the trees they feast on. Over the 20 years Boutin has spent studying this chess match, he has noticed a surprising pattern. Red squirrels are somehow able to predict years when a bountiful crop is about to occur and remarkably produce a second litter of babies to take advantage of the onslaught of food about to arrive

Story Teller: Dr. Stan Boutin from the U of A’s Faculty of Science http://www.physorg.com/news85937631.html

Aknowledgements : John Scott

How human stood up

2007-02-21T02:10:00.000-08:00

"Even if this is an exaggeration, it should at least encourage us to look elsewhere for possible benefits of our unusual gait. It arouses the suspicion that, whatever non-locomotor benefits of bipedality we might propose as drivers of its evolution, they probably did not have to fight against strong locomotor costs.
"What might a non-locomotor benefit look like? A stimulating suggestion is the sexual selection theory of Maxine Sheets-Johnstone, of the University of Oregon. She thinks we rose on our hind legs as a means of showing off our penises. Those of us that have penises, that is. Females, in her view, were doing it for the opposite reason: concealing their genitals which, in primates, are more prominently displayed on all fours. This is an appealing idea but I don't carry a torch for it. I mention it only as an example of the kind of thing I mean by a non-locomotor theory. As with so many of these theories, we are left wondering why it would apply to our lineage and not to other apes or monkeys." Taken from :The Ancestor's Tale: A Pilgrimage to the Dawn of Evolution By Richard Dawkins :91.

Original Storyteller : Maxine Sheets-Johnstone, of the University of Oregon
Re-storyteller : Richard Dawkins www.orionbooks.co.uk/extras/richarddawkins_theancestorstale.pdf

Storyteller: Prof Robin Crompton, Biomedical Sciences, Liverpool University.
Early humans 'learnt to walk in the trees

Story Research: http://mynym.blogspot.com/2006/02/nomogenesis.html

How Jonny rejected vegetables

2007-02-17T23:58:00.000-08:00

"DARWIN'S FUSSY EATERS. The next time the kids are fussing about eating anything other than Mac and cheese, bear in mind that they may be hardwired to be picky. British scientists recently theorized that young children shun many vegetables and strange meats because of an evolutionary safeguard that protected them from toxic plants and food poisoning. Knowing this won't convince them to eat broccoli, but you can at least take comfort in the fact that it's not your cooking

Denyse O'Leary at Post- Darwinist found this very nice story. See her article at "Just-so stories from evolutionary psychology: Why kids don’t eat their vegetables"

Story Teller: Better Homes & Gardens ( January 2004, 111)

Story Research: http://post-darwinist.blogspot.com/2005/09/just-so-stories-from-evolutionary.html

How Lizard got his Horns

2007-02-16T23:56:00.000-08:00

When a loggerhead shrike catches a lizard, the bird often impales it on a thorn or a spur of barbed wire and then leaves the carcass hanging, explains evolutionary biologist Edmund D. Brodie III of Indiana University in Bloomington. He and his colleagues compared the length of the horns on dangling remains of horned lizards with horn lengths of lizards still alive. The living lizards typically had slightly longer horns, the researchers report in the April 2 Science.

This lizard's multiple pairs of horns, facing backward and sideways from its skull, are "as hard and as sharp as you think they are," says Brodie. When a predator pounces to grab the lizard's body, the reptile rears back its head to stab the attacker.

The team found that, on average, the living lizards had longer horns than the dead ones. The difference was tiny—2 millimeters for one horn pair and 1 millimeter for another. Brodie points out that this difference represents 10 percent of the horn length.
That's enough for natural selection, he says. The team calculated that the horns' length, under the pressure of bird attacks, could change in as few as 21 generations. Brodie cautions that the research shows only a current selection pressure, not what might have driven earlier evolution.

Storyteller: Edmund D. Brodie III of Indiana University in Bloomington.
http://www.phschool.com/science/science_news/articles/long_horns_win.html

Story Research: http://creationsafaris.com

How Peacock got his Tail

2007-02-16T23:34:00.000-08:00

Anders Moller of the Laboratoire d'Ecologie at the French national research center in Paris has been interested in why males should have multiple ornaments. For instance, male peacocks not only have a long tail, but they are brightly colored and have eye spots, a crest on their head, spurs on their feet, and a mating call.
Moller's theory was that these ornaments signal different aspects of the male's quality to a female.

"Our main finding is that females are looking at different aspects of a male's immune competence," said Moller. Males, in effect, are walking billboards advertising their health and status.
And these things matter. Previous research has shown that in chickens and quail, at least, the immune system is under genetic control so offspring will inherit their parents' ability to fight parasites.
Thus, it pays for females to be choosy because their chicks, in turn, will survive better and mate with other, equally picky females.

Storyteller: Anders Moller, Laboratoire d'Ecologie, French national research center
Source: http://news.nationalgeographic.com/news/2002/09/0909_peacock.html
Aknowledgements : http://creationsafaris.com/

StoryUnteller: Female Peacocks Not Impressed by Male Feathers

How Sole's eye wandered

2007-02-16T22:23:00.000-08:00

Richard Dawkins explains the flatfish's evolutionary history as:

"... bony fish as a rule have a marked tendency to be flattened in a vertical direction.... It was natural, therefore, that when the ancestors of [flatfish] took to the sea bottom, they should have lain on one side.... But this raised the problem that one eye was always looking down into the sand and was effectively useless. In evolution this problem was solved by the lower eye 'moving' round to the upper side."

Storyteller: Richard Dawkins in the Blind Watchmaker
http://en.wikipedia.org/wiki/Flatfish

Story Research: National Geographic Finds Opportunity to Conflate Intelligent Design with Creationism while Misreporting Fish Fossil

Flatfish Evolution revealed

How Giraffe Got his long Neck

2007-02-16T22:21:00.000-08:00

Darwin was the first to propose that long necks evolved in giraffes because they enabled the animals to eat foliage beyond the reach of shorter browsers. That seemingly sensible explanation has held up for over a century, but it is probably wrong, says Robert Simmons. Simmons, a behavioral ecologist at the Ministry of Environment and Tourism in Windhoek, Namibia, believes giraffes developed long necks not to compete for food but to win mates. Simmons was studying eagles in Sabi Sand Reserve in South Africa when he happened to come upon a pair of male giraffes locked in combat. Male giraffes battle for mates by swinging their powerful necks--which can be over six feet long and weigh more than 200 pounds. The momentum generated allows them to slam their heads into their opponents with vertebrae-shattering--and occasionally lethal--force. In these contests, males with the longest, thickest necks usually prevail. As Simmons watched the fight, he became convinced that this competition for mates, not stretching for treetop food, was what drove the evolution of the neck. If competition for food had spurred the elongation, says Simmons, then you would expect giraffes to graze mainly from tall acacia trees beyond the reach of other savanna inhabitants. But giraffes feed mostly with their necks bent, along low bushes. Moreover, their short, stubby horns probably evolved to better concentrate the force of their head blows.

Storyteller: Robert Simmons. Simmons, a behavioral ecologist, Windhoek, Namibia
Source: DISCOVER 1997 How the Giraffe Got Its Neck

Story Researcher : The Evolution of the Long-Necked Giraffe — A Preview
See Also: The Evolution of the Long-Necked Giraffe

How Butterfly Got her Spots

2007-02-16T09:58:00.000-08:00

In the big scheme of animal evolution, according to Keys, a graduate student in Carroll's lab, the decoration of a butterfly's wing is a much more recent invention than the building of the wing itself: "Evolution, somewhere along the line, took this system and came up with a way to reuse it in an entirely new context while maintaining its original function."

"To our thinking, the reuse of genes makes innovation easier," said Carroll, a biologist whose work has helped resolve the role genes play in making such things as arms, legs and wings.
"Evolution," he said, "is working by integrating sets of things it already has. You're using a circuit over and over again."
How butterflies co-opt existing genetic programs to create eyespot patterns that help them fool predators, said Carroll, may in fact be a general mechanism animals use to create "luxury items -- teeth, antlers, shells, hair, coloration -- in the course of evolution."
These luxuries can be further tinkered with at the genetic level to create new variants, such as the enormous diversity of pattern and color in butterflies, or the array of antlers sported by different members of the deer family such as elk and moose.
"Once you make a new connection, it can independently evolve" through the interplay of development and genetic change, Carroll said. "Evolution can muck with that by changing things in the circuit."
"One of the amazing things about butterflies is that these genetic programs result in a tremendous variety of color patterns, not structures," said Lewis.
"Few would have guessed," said Keys, "that those beautiful color patterns evolved from the same genetic processes which all insects use to shape their wings."

Storyteller: Sean B. Carroll of the University of Wisconsin
Source : How the Butterfly Got its Spots, and Other Mysteries

Story Research: The Design of Life
Source: Did the eyespots of butterflies and moths evolve to deter predators?

How Elephant Got his Trunk

2007-02-16T09:53:00.000-08:00

On Monday 9 August 2004, BBC Radio 4 broadcast the first of a series on “Real Just So Stories”. Stimulated by Rudyard Kipling’s stories for children, the programme presenter, Alistair McGowan, asks: “What really happened?” This episode was entitled “How the Elephant Got Its Trunk”
Adrian Lister, Professor of Palaeobiology at University College London, explained that the trunk leaves no fossils. However, the skull can be studied for evidence of muscle attachment points. He said that all the potential ancestors for the elephant were small, possibly amphibious, and rather like a hippo in not having a trunk. However, as the animals grew in size, they would have found it difficult to get supplies of water. They could not stoop to drink because of their short necks and stocky legs. A trunk would allow them to get water without stooping. The ancestral elephants were “blessed by evolution with this wonderful structure”.

Storyteller : Adrian Lister, Professor of Palaeobiology at University College London

Story Research: http://www.biblicalcreation.org.uk/scientific_issues/bcs143.html

How Whale Learned to Swim

2007-02-16T09:35:00.001-08:00

"In North America the black bear was seen . . . swimming for hours with widely open mouth, thus catching, like a whale, insects in the water. Even in so extreme a case as this, if the supply of insects were constant, and if better adapted competitors did not already exist in the country, I can see no difficulty in a race of bears being rendered . . . more and more aquatic in their structure and habits, with larger and larger mouths, till a creature was produced as monstrous as a whale"

Storyteller: Charles Darwin, Origin of Species, First edition (Not in the 6th edition)

Story Research: Two Just So Stories
Research intelligent design Just-so_stories