Swim Bladders and Snake Venom

While the ID folks continue to blather about the impossibility of complex systems evolving naturalistically, real scientists are busy unravelling the steps by which such evolution actually occurred.

The March 18 issue of Science contains <a href=http://www.sciencemag.org/cgi/content/full/307/5716/1705a>this research report</a> and accompanying <A href=http://www.sciencemag.org/cgi/content/full/307/5716/1752>technical article</a> (only available by subscription, apparently), about recent work on the evolution of swim bladders in fish. Meanwhile, Bryan Fry of the University of Melbourne in Australia has published <a href=http://www.genome.org/cgi/content/full/15/3/403>this article</a> in which he unravles some of the mysteries of snake venom evolution. This work is described in layman's terms by Carl Zimmer in <a href=http://www.nytimes.com/2005/04/05/science/05veno.html?pagewanted=1>this article</a> from The New York Times.

From the Science article:

Scuba divers wear air-filled dive vests to move up and down in the water column. Researchers have now used the fish family tree to piece together how the piscine equivalent, an internal air sac called a swim bladder, evolved a complex capillary network and special hemoglobin molecule to inflate it with oxygen. Moreover, according to the proposal presented on page 1752 by Michael Berenbrink of the University of Liverpool, United Kingdom, and his colleagues, these innovations helped fish expand their species diversity. “The scenario developed presents a fascinating picture of the evolution and radiation of fish,” says Bernd Pelster, an animal physiologist at the University of Innsbruck, Austria.

And from Zimmer's NY Times article:

Ultimately, this rush is not what drives Dr. Fry, who is 34. His goal is to decipher the evolution of snake venoms over the past 60 million years. Reconstructing their history will help lead to medical breakthroughs, Dr. Fry believes. For the past 35 years, scientists have been turning snake venoms into drugs. Just this February, Dr. Fry and his colleagues filed a patent for a molecule found in the venom of the inland taipan that may help treat congestive heart failure.

Understanding the evolution of snake venoms will speed up these discoveries immensely, Dr. Fry predicted. “You need a good road map to get your research going,” he said.

I've posted further excerpts and additional commentary on these articles over at <a href=http://evolutionblog.blogspot.com>EvolutionBlog</a>: Swim bladders <a href=http://evolutionblog.blogspot.com/2005/04/evolution-of-swim-bladders.html>here</a>, Snake venom <a href=http://evolutionblog.blogspot.com/2005/04/evolution-of-snake-venom.html>here</a>. Enjoy!