Re: [asa] Back to Darwin

From: David Campbell <>
Date: Fri Apr 11 2008 - 16:33:02 EDT

> Drive to complexity seen in animal evolution
> This news item points to a trajectory to increasing complexity as being the
> norm, rather than devolution, with specific instances of the latter being
> deucedly difficult to find.

Complications: how is complexity measured? What if one aspect gets
more complex and another gets less so?

Some things have gotten more complex over time; others seem to have
stayed fairly simple. Can you get much less complex than a simple
bacterium and still function? If not, then random variation in
complexity coupled with an absolute lower limit would produce a net
increase in complexity over time.

Loss of a particular complex feature is common enough-snakes, whales,
caecilians, legless lizards, etc. have lost limbs; bivalves have
largely lost their heads; rapidly reproducing taxa often have reduced

Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
To unsubscribe, send a message to with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Fri Apr 11 17:02:21 2008

This archive was generated by hypermail 2.1.8 : Fri Apr 11 2008 - 17:02:21 EDT