Tom asks:

>I have a rather simple question:
>
>Evolution shows a steady increase of complexity (or functionality).
>
>Where has evolution been observed to produce a new species
>that is "simpler" than its predecessor(s) and yet fit enough to
>survive/proliferate?

Examples abound in nature.  There are probably no more complex organs than eyes
and hands, yet these structures have been repeatedly lost during the course of
evolution when they prove to longer be functional or advantageous.

Every snake is a descendent of a lizard that lost its legs. If we could will
snakes off of the planet, in the manner of St. Patrick, "snakes"
(or snake-like
animals) would recur virtually instantly. Indeed, they're doing that now.
"Legless lizards" are common all over the world. See e.g.:

    http://www.lhs.berkeley.edu/Biolab/wlhleglesslizard.html

While they're not technically snakes (snakes have to meet a certain set of
morphological criteria before they are classified as snakes), they're the
ecological equivalent of snakes.

Of course, lizards aren't the only vertebrate to become "less complex" by
shedding their legs. Whales and dolphins have done the same thing. Of interest,
the pattern always seems to be the same. The rear legs are lost first, and then
the forelimbs, if they're to be lost at all.

Eyes are just as commonly lost in cave-dwelling crickets, fish and salamanders.
In the absence of light, there's just no reason for the continued maintenance
of these extremely expensive organs. But more than just that, I -- and
virtually every other biologist -- agree completely with August Weismann, who
wrote in 1893, "In my opinion every organ is kept at the peak of its
conformation only by continuous selection" 

Teeth have similarly been lost in birds. Only remnants of the code that once
encoded the giant, flesh-ripping serrated teeth of Tyrannosaurus rex still
exist in birds today. But that code can still be elicited and teeth buds can be
forced to reappear in developing bird embryoes even now.

"Complexity reduction" is not hard, either in evolved or
engineered structures.
All you have to do is simply stop expressing the code. That's often a change of
nothing more than a single base pair (although it's more generally a change in
some form of upper-level regulation). Rather it was building the complexity to
begin was the tough evolutionary slog.

As Mr. Spock said in one of the early Star Trek movies, "Destruction is simple.
It's creation that's difficult."

Wirt Atmar
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