name_and_address_supplied{at}hotmail.com (Name And Address Supplied) wrote
in news:cl65t6$bde$1{at}darwin.ediacara.org: 

> "John Edser"  wrote in message
> news:... 
>> Name And Address Supplied wrote:
> 
>> > NAS:-
>> > The trade-off described by "Disposable soma", as
you have described
>> > it, is equivalent to general "Antagonistic
pleiotropy". In both
>> > cases, variants arise which either promote functioning early or
>> > late, and early is favoured as here reproductive value is highest.
>> 
>> JE:-
>> The phrase: "reproductive value is highest" lacks
>> rigor, yet the entire argument depends on it.
> 
> Apologies for not defining every single term that I use. I have
> assumed some basic familiarity with evolutionary concepts.
> Reproductive value is well defined, and is a key player in the
> evolution of senescence, so I thought it unnecessary to go into more
> detail.
> 
> I am astonished that, amidst all the wooly group selectionist thinking
> which is flying around this thread, I am being accused of lack of
> rigour. I do not deny that group selection could have selected for
> individuals to die so as to not cause a drain of resources for the
> community, however I do know that such careless appeals to group
> selection can be extremely misleading.

Yeah, well, look at who is doing the accusing - John has a strong 
tendency towards demanding absolutes  even where they are inappropriate.

Early reproductive value is obviously important, and may contribute to 
menopause, but it seems an unlikely cause for senescence, at least in 
iteroparous species. I think the existence of long-lived species argues 
strongly against the idea of senescence as a group selected trait - 
especially since many long lived species are social animals. I agree with 
you that I would not say it can't happen - evolution will use whatever 
leverage it can get in a particular situation - but the best explanation 
for senescence is that something like advanced age can't be selected for 
unless it is useful, and even if individuals do survive for long periods 
reproduction at an early age will outweigh later reproduction unless 
there are other advantages (e.g. larger size, greater knowledge, more 
accumulated wealth) which accrue to delayed reproduction.  

Yours,

Bill Morse
---
þ RIMEGate(tm)/RGXPost V1.14 at BBSWORLD * Info{at}bbsworld.com

---
 * RIMEGate(tm)V10.2áÿ* RelayNet(tm) NNTP Gateway * MoonDog BBS
 * RgateImp.MoonDog.BBS at 10/23/04 4:42:34 PM