Re: Evolutionary advantages

[IDMiamiBob@aol.com]

Dominic writes:

> As to the evolutionary value of eating your young, (after watching my
>  roommate's dempseys demolish their 150+ fry in a 90 gal filled with
>  other dempseys and giant danios), I suppose that, as
>  a parent fish, if you had put time and effort (body-mass, really) into
>  generating small reproductions of yourself, if you were convinced that they
>  were not going to survive - for whatever reason - it would make sense to
>  re-enlist the resources you had squandered (eat 'em!) so as to prepare for
>  another, hopefully more successful attempt at reproduction.
>  
>  I don't know if i have figured anything out here - does it make any sense?
>  
That is the conventional argument.  If you follow it through, that implies 
that the folks figure the kids can't make it.  Now- Why not?  Water quality 
or food availablity are the only two factors I can think of in a tank where 
predators have been eliminated or controlled, and disease is pretty much 
eliminated.  So- whatcha gonna do about it?

But then, the other camp argues (whether they realize it or not) that the 
parents don't recognize the fry as their own progeny, or they see the fry as 
genetic competitors.  When a male lion takes over a pride, he kills all the 
cubs in the pride.  Why?  Two reasons have been presented- It brings the 
females into estres, and it dedicates the entire pride to promoting the 
survival of his DNA intead of his predecessor's.

Bob Dixon


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