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Re: Evolutionary advantages



When I was teachng High School Agriculture ( now I'm back teaching what I'm
trained to  - High School Biology ) I use to do an activity with the kids to
select the best cattle for breeding programs from stud brochures based on
things called EBVs ( estimated breeding value ). These were a selection of
characteristics that were determined to be inheritable characteristics.
Among the traits was mothering ability. It seems that the ability of a
female cow to instinctively look after a calf, behaviourally ( protection
etc ) and physically ( milk production etc ), is determined in some way by
her genetic constitution. It was also shown that parenting was a feature
among cattle that would deteriorate if successive generations were removed
from their mother at a very early age ( as they are with dairy cows to
maintain lactation ). So it seems that in the animal world the instinctive
behaviour associated with parenting is both learned and inherited to some
extent. It stands to reason that some of this may also apply to our fish.
Why shouldn't it when their [ cichlid ] reproductive behaviour is so
complex. I'm not saying that there aren't dietary and environmental aspects
to this puzzle but maybe the reason that our fish eat their fry when all
other selective pressures, such as predators and disease, have been reomoved
is because they may not have the genetic constitution to endere themselves
to raising fry or maybe they themselves, and many generations before them,
have been removed from their parents so the learnt aspect of parenting is
not present. Hmmmm - all this is just speculation but maybe we should be
taking more care when breeding our fish to; 1. select the parents more
carefully based on features other than pretty looks, and 2. leave the fry
with the parents as long as we can.

This doesn't explain why wild caught fish do the same thing though inicating
there is more to this than genetics or education. Who knows huh !

Regards,

Simon Voorwinde

=========================================================
svavev@hunterlink.net.au
http://thecichlidtank.cjb.net
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