Re: [asa] Origins: Francis Collins and ID

This just in:

  *University of Queensland research has found the "missing link" in the
evolution of the eye. *
Professor Shaun Collin, from UQ's School of Biomedical Sciences, together
with colleagues from the Australian National University and the University
of Pennsylvania, have identified animals that have eyes that bridge the
evolutionary link between those designed to simply differentiate light from
dark to those that possess a camera-like eye.

Professor Collin said his research gathered evidence from multiple branches
of biology, in support of a gradual evolution of the eye, and it proposes an
explicit scenario to explain how it was that our eye emerged.

"Charles Darwin wasn't able to reconcile the evolution of the eye given its
complexities and diversity of eye designs," Professor Collin said.

"So it was a major surprise for us that we have found what appears to be a
clear progression from a simple eye to a complex eye, which occurred over a
relatively short period (30 million years) in evolutionary history."

Professor Collin said the researchers studied a very primitive fish, the
hagfish, to discover the missing link.

"This animal diverged from our own line somewhere around 530 million years
ago," he said.

"Hagfish are simple, eel-shaped jawless and ugly animals, that inhabit the
oceans at great depth, and that are renowned for the revolting 'slime' they
exude when disturbed.

"They behave as if blind, though they have a primitive eye-like structure
beneath an opaque eye-patch on either side of the head. Previously it had
widely been thought that the hagfish eye had degenerated from a lamprey-like
precursor.

"But our research suggests hagfish did not degenerate from lamprey-like
ancestors, but are instead the remnants of an earlier sister group."

Professor Collin's research with Professor Trevor Lamb from the Australian
National University and Professor Ed Pugh from the University of
Pennsylvania, was recently published in *Nature Reviews Neuroscience*.

Source: University of Queensland

On 12/3/07, David Campbell <pleuronaia@gmail.com> wrote:
>
> Evolution is highly directional, constrained by natural selection.
> That's also the answer to "where does the information come from?"-the
> environment provides the information; evolution represents attempts to
> produce adequate matches to the information given by the environment.
>
> The eye is a popular but bad example of a challenge for evolution.
> This is because even a rudimentary eye is useful. For example, many
> single-celled organisms are able to detect and respond to light.
> Within animals, there is the range from no apparent light sensitivity
> through mere light detection, basic capability to detect motion, shape
> recognition, etc. to well-developed lenses and various systems of
> color recognition. Parallel development of lensed eyes in mollusks
> (actually multiple versions), vertebrates, cnidarians, and annelids,
> along with the somewhat different compound eye approach in many
> arthropods, illustrates the evolutionary sequence well. Eyes can be
> far from perfect and still functional. I need things to be within 20
> cm to be fully in focus, but would still easily be able to detect a
> large animal moving towards me while it was still a ways off. We
> manage with a lot fewer colors than some birds.
>
> --
> Dr. David Campbell
> 425 Scientific Collections
> University of Alabama
> "I think of my happy condition, surrounded by acres of clams"
>
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Received on Mon Dec 3 17:48:46 2007