"Tim Tyler"  wrote in message 
news:ck2bt9$1t2q$1{at}darwin.ediacara.org...
> Lennart Kiil  wrote or quoted:
>> "Tim Tyler"  wrote in message
>> > Michael Ragland  wrote or quoted:
>> >> Michael Ragland  wrote or quoted:
>
>> >> MAYR: There's absolutely no chance of the human species evolving. 
>> >> First
>> >> of all, we can never speciate. We cover every niche,
every spot on the
>> >> earth, so there's no opportunity for isolation. Moreover, I do not 
>> >> feel
>> >> there's any natural selection in any positive sense going on right 
>> >> now.
>> >> Of course, there are those who have talked about
eugenics, but we all
>> >> know that eugenics is impossible for many reasons. I can't see the
>> >> development of man into superman or anything like that.
Theoretically 
>> >> we
>> >> could have cultural evolution and develop higher and
better concepts.
>> >> But if you have no basis for a change in genes, then
unfortunately you
>> >> can only develop through cultural evolution.
>> >>
>> >> Tim:
>> >> Ernst Mayr doesn't have a clue about human evolution :-(
>> >>
>> >> MR:
>> >> How so? I think Mayr was referring to Darwinian evolution.
>> >
>> > "There's absolutely no chance of the human species evolving."
>> >
>> > The statement is idiotic.  Does Mayr think all humans have
>> > equal numbers of children?  Has he forgotten about the
>> > existence of sexual selection?  What on earth is he thinking of?
>>
>> Not so fast. That fact that not all people have equal numbers of children
>> does not necessarily warrant evolution, especially not in any directional
>> sense. Such a claim relies on the premise that on average there is some 
>> kind
>> of correlation that connects the people having more children with a 
>> certain
>> genetic makeup.
>>
>> The same basically goes for sexual selection.
>
> That doesn't make the statement that we are not evolving any less
> stupid.

I agree that Mayr far overstated the case when saying
"There's absolutely no chance of the human species evolving."
This statement borders on the absurd.

What I was objecting to was your inference from differential reproductive 
output to evolution.
Here is why, imagine we now live in an environment where number of offspring 
relies more heavily on choice and not so much on natural capability. This 
would reduce the correlation between reproductive succes and genetic 
evolution because there might not necessarily be any segmented genetic 
composition to the people choosing to have more children.

For example I live in Denmark where we have the socalled wellfare state. 
This basically means that the burden of having children has been distributed 
over society at large. This means that anyone, regardless of their natural 
potentials can have a lot of children. This renders the whole idea of 
selection obsolete. Natural selection because natural potentialities are 
leveled out by governmental redistribution. Sexual selection because the 
obligation to help women support children has been tranfered from the 
individual man to the state. In short contingency and randomness is becoming 
relative more important than more deterministic forces now than earlier in 
history. Thus I do not agree that evolution (in a directional sense) occurs 
faster in humans now than earlier, quite the opposite.

>
> There's a reasonable book-length treatment putting the case for humans
> evolving in modern times faster - if anything - than before - due
> to being in an environment which is different from the one they
> evolved in - and because the difference in reproductive success
> between the most successful reproductives and the least in modern
> times is likely greater than at any point in history - i.e.
> the Guinness record holders for offspring lived rather recently.
>
> The book is: "Children of Promethius" - by Christopher Wills.

As noted above, it does not sufice that the environment is merely different 
to indicate more evolution, the environment has to be conducive of 
directional evolution for this argument to hold. That is, it has to be an 
environment that makes genes visible to selection. Modern society more than 
anything obscures the genetic component.

>
>> > As for speciation, it seems *highly* likely that strains of
>> > asexual human clones will arise in the near future. [...]
>>
>> what is your concept of 'near future'?
>
> The first human clones?
>
> Cloneaid says they have 13 cloned human babies so far
> [on http://www.clonaid.com/news.php].
>
> I don't know if that is true - but at least that number of
> human clones will probably exist by this time next year.

Ahh ok, by asexual clones I thought you meant clones that could actually 
reproduce asexually like parthenogenetic strains in some animals, this is an 
entirely different matter.
And it is going to be a while before clones start to matter in the global 
household, compare:
13 : 6,400,000,000

>
> Some celebrities are already thinking about it:
>
> ``"[...] in reality I think it'd be great if cloning would
exist," said
>  Schwarzenegger. "I would clone four or five of me: one to take care of
>  the family, one to take care of the filming, one to go out and direct
>  movies, one to go into politics, one to go and play golf all day
>  without feeling guilty."''

Well, maybe then we can finally get our pizza on time!

>
> - http://tinyurl.com/66o2m ;-)
> -- 
> __________
> |im |yler  http://timtyler.org/  tim{at}tt1lock.org  Remove lock to reply.
>

Best regards,
Lennart Kiil
www.zensci.com
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