Storyteller: Alexander Riedel from the Karlsruhe State Museum of Natural History
In the absence of any other proof, the thumb alone would convince me of God's existence. (Isaac newton)
Sunday, June 8, 2014
Storyteller: Alexander Riedel from the Karlsruhe State Museum of Natural History
Story Teller : Zoologists Malcolm Burrows and Gregory Sutton at the University of Cambridge, UK
Tuesday, December 11, 2012
"First, and foremost, this finding helps us to understand the power that the modification of gene expression has on shaping our bodies," says Dr. José Luis Gómez-Skarmeta of the CSIC-Universidad Pablo de Olavide-Junta de Andalucía, in Seville, Spain. "Second, many genetic diseases are associated with a 'misshaping' of our organs during development.
In the case of genes involved in limb formation, their abnormal functionis associated with diseases such as synpolydactyly and hand-foot-genital syndrome."
In order to understand how fins may have evolved into limbs, researchers led by Dr. Gómez-Skarmeta and his colleague Dr. Fernando Casares introduced an extra gene known to play a role in distinguishing body parts, at the tip of a zebrafish embryo's fin. Surprisingly, this led to the generation of new cartilage tissue and the reduction of fin tissue -- changes that strikingly recapitulate key aspects of land-animal limb development. This result indicates that molecular machinery capable of activating this control element was also present in the last common ancestor of finned and legged animals and is proven by its remnants in zebrafish," says Dr. Casares
Wednesday, June 20, 2012
Monkeys smack their lips during friendly face-to-face encounters, and now a new study says that this seemingly simple behavior may be tied to human speech.
Previously experts thought the evolutionary origins of human speech came from primate vocalizations, such as chimpanzee hoots or monkey coos. But now scientists suspect that rapid, controlled movements of the tongue, lips and jaw were more important to the emergence of speech.
For the study,W. Tecumseh Fitch and colleagues used x-ray movies to investigate lip-smacking gestures in monkeys. Mother monkeys do this a lot with their infants, like humans going goo-goo-goo in a baby's face while playing. Fitch,and his team determined that lip-smacking is a complex behavior that requires rapid, coordinated movements of the lips, jaw, tongue and the hyoid bone.The smacks occur at a rate of about 5 cycles per second - the exact same rate as for average speed human speech. Put vocalizations and these lip smacks together and voila- the basis of speech. As our ancestors began to live closer together and to cooperate, perhaps the conditions were just right to promote this skill. It's a mystery, though, as to why monkeys never got our gift of gab. The "singing" component of speech, which requires voluntary control over the larynx, remains an evolutionary mystery too.
StoryTeller: W Tecumseh Fitch, Department of Cognitive Biology University of Vienna
Source: Discovery News Lip Smacks of Monkeys Prelude to Speech?
Story Research : The wrong way to understand the origin of human language
Wednesday, May 9, 2012
Bats and toothed whales had many opportunities to evolve echolocation techniques that differ from each other, since their nearest common ancestor was incapable of echolocation.
On a purely physical basis, you would predict that whales and bats would operate at different [echolocation] rates and frequencies," Madsen says. "But instead, they operate at the same rates and frequencies." The similarities support the idea that the acoustic behavior of bats and whales may be defined by the auditory processing limitations of the mammalian brain.
Storyteller: Peter Teglberg Madsen of Aarhus University, Denmark
Source: Bats, Whales, and Bio-Sonar: New Findings About Whales’ Foraging Behavior Reveal Surprising Evolutionary Convergence
Monday, March 26, 2012
The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource, usually because it may not occur in plentiful supply in their habitat, making it hard for them to predict when they will see it again. Standing on two legs allows them to carry much more at one time because it frees up their hands.
In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four.
Storyteller: Brian Richmond, George Washington University
Source: Humans Began Walking Upright to Carry Scarce Resources, Chimp Study Suggests
Story Research : Design perspectives and the physiology of walking, ARN
Wednesday, February 15, 2012
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 from Hungary and Sweden
Source: How the Zebra got its stripes
Saturday, August 27, 2011
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
Thursday, December 30, 2010
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".
Source: Rare Bees Make Flower-Mud "Sandwiches"
Sunday, December 5, 2010
Wednesday, November 3, 2010
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
Monday, September 6, 2010
Storyteller: Catania, K. Olfaction: Underwater 'sniffing' by semi-aquatic mammals.
Source: The star-nosed mole's amazing appendages
Sunday, July 4, 2010
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
Thursday, April 15, 2010
Storyteller: Parrish Brady, University of Texas
Source: Beetles stand out using Avatar tech
Wednesday, January 27, 2010
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
Monday, January 4, 2010
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
Sunday, November 29, 2009
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.
Wednesday, October 28, 2009
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
Thursday, September 24, 2009
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
Friday, August 14, 2009
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
Thursday, February 19, 2009
"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
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
Monday, January 19, 2009
, 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
Friday, October 10, 2008
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?
Tuesday, September 30, 2008
"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
Source: Tree of Life gets stung by JellyFish