Re: Herbivore protection

[Jeffrey Martz <martz@holly.ColoState.EDU>]

John Bois wrote...
> I don't think so.  Surviving offspring can be achieved by having smaller
> clutch size too.  It is more Darwinianly fit to have one egg survive
> (because, perhaps, of your parental investment) than a thousand perish!

     Both strategies are equally valid and employed successfully by
animals today.  High "K" strategists take really good care of a few
offspring, and high "r" strategists produce a whole lot of sacrificial 
eggs, but both get the "one egg" out. I might also point out that "r"
strategies are more common then "K" strategies, and produce the most
prolific animal species alive.   

> I don't understand this.  Surely it would be better to deprive predators
> of your offspring altogether.  To hell with 'em!  This reminds me of H.
> G. Wells' _The Time Machine_ where the placid peoples march into the
> caverns
> to be eaten.  As long as a few sacrifice themselves the rest live an
> idylic life.

      It works, doesn't it?  As I just noted this is exactly what most
living animals do.  Evolutionary survival depends on the propogation of
your genetic code.  If you have to sacrifice 1,000 offspring to do it, you
still win if you get one survivor that is capable of repeating the whole
process over again.  Some species (high K) say "to hell with em", some
(high r) feed the Morlocks, but both survive.       

> Organisms that have no protection against predation may have
> selection to either increase clutch size _or_ reduce predation.  I
> maintain that a clutch size of 18??? or so for a hadrosaur cannot be
> interpreted as a hedge against predation at the nest.  Certainly, if these
> creatures all had that many offspring survive the cretaceous would have
> been chock-a-block with them.  But whether these numbers were culled at
> the nest or beyond is speculation.

    Then wait a minute; if they weren't culled at the nest OR beyond, 
where did they go?  Are you proposing other mortality factors like disease
were more prevalant in the Cretaceous then predation?      

> The only decent arguement for this is the
> possibility that colonizers are better able to synchronize incubation.
> But at an incubation time of at least one month (does anyone argue this)
> how critical can timing be?

    Many colonial nesting bird species synchronize themselves (within a
few days, if I'm not mistaken) in this way.  Exactly HOW they do it, I'm
not sure. 

LN Jeff
O-
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