Anthony Cerrato  wrote in news:bnve1j$2sn6$1
{at}darwin.ediacara.org:

> 
> "William Morse"  wrote in message
> news:bnsd04$1srl$1{at}darwin.ediacara.org...
>> Anthony Cerrato  wrote in
> news:bnn5fr$eit$1
>> {at}darwin.ediacara.org:
>>
>> > One thing which is obvious in my non-expert observation
> of
>> > sexual vs nonsexual creatures: only sexual creatures
> fall
>> > into the class of what I'd call "complex" life 


>> If memory serves me both dandelions and rotifers reproduce
> exclusively
>> asexually.


> Hi Bill. I'm sorry that I didn't explain what I really meant
> more clearly. I put "complex" life in quotes initially since
> I didn't mean it in the usual biological technical sense (I
> guess--I'm a chemist not biologist :).) What I meant was
> complex in the very subjective sense of larger animals for
> example; e.g., increased complexity being from
> bacteria/prokaryotes, to your dandelions and rotifers, to
> fish, reptiles/small mammals, to horses, monkeys, and
> finally, man.
 
> While evolution isn't necessarily directed, there has been a
> persistent increase in complexity with time in my,
> admitedly, loose view of complexity (unfortunately, I am not
> familiar enough with more precise current non-traditional
> definitions of this kind of complexity tho.) Do you agree
> that in my above "list" that the higher degree of some loose
> form of complexity demands (bi)sexuality, or, would it ever
> be possible to reach animals as complex as horses, monkeys
> and humans through evolution without sex?


The subject of a persistent increase in complexity with time has a 
somewhat tangled history in evolution. Gould wrote a book - "Full 
House" - arguing that the increase in complexity was not a result of 
direction, but simply the net result of a drunkard's walk away from zero 
complexity. I agree with you and  disagree with Gould on this point, and 
in fact there was a recent reference in Science that seemed to verify an 
overall increase in diversity since the Cretaceous. But that may be 
different from your overall point, which is whether complexity can be 
achieved without sex.

A similar question was in fact very recently discussed on this newsgroup. 
I and others argued that whether evolution could proceed without sex, sex 
would be an inevitable result of evolution. This point was very well 
fleshed out by Wirt Atmar in a follow in early October on a thread about 
"Levels of Selection". So even if you _could_ reach complex animals 
without sex, you _wouldn't_ reach complex animals without also reaching 
sex. 

Yours,

Bill Morse




Reference previous discussion on gender by Wirt
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