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Re: Mammalian success and egg predation,



On Thu, 13 Jun 1996, John Bois wrote:

> > BUT live-bearing is by far not the only difference between mammals and 
> > the rest of the world, so this seems to me to be a very weak statement. 
> > Any flaw in this line of thinking?
> 
> Yes.  It is a critical difference.  Listen to John McLaughlin from 
> _Synapsida_ (he's actually talking about escape from egg-laying for 
> mammals--but I believe it applies to all egg layers): "Eggs are highly 
> fragile objects, the most vulnerable interval in an egg-layer's life style." 

Being as I am quoted here, I want to clarify: I think that eggs were the 
most vulnerable interval particularly in the life-cycle of tiny 
ground-dwelling vertebrates like early mammals that likely nourished 
their young with milk.  For dinosaurs, while eggs may have been 
vulnerable, I rather doubt that the parents put up with overmuch guff in 
the egg-stealing department.  I think that the long dominion and sheer 
variety of dinosaurian evolution suggests that dinosaurs early worked out 
any problems they may have had with eggs, and that anything that mucked 
about with their eggs was a fair candidate for leaving fewer genes in the 
future.  

John C. McLoughlin