" We are skeptical of claims for the ability of random mutation and natural selection to account for the complexity of life. Careful examination of the evidence for Darwinian theory should be encouraged." - Dissent from Darwin

Natural selection [is used] carelessly as a mantra, as in the evidence-free “just-so stories” concocted out of thin air by mentally lazy adaptationists. (Stephen Jay Gould)

In the absence of any other proof, the thumb alone would convince me of God's existence. (Isaac newton)

Monday, February 25, 2008

How HUMAN got hiccups

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