ANDREA SPIEGLE <[EMAIL PROTECTED]> wrote
>You probably don't see those colors in the wild because any non-agouti
>colors that showed up would be more easily killed by predators, as they
>wouldn't blend in to the surrounding sand. It's the same thing with a
>lot of albino animals, they are either more easily noticed by their
>predators and are eaten, or they're seen by their prey and can't eat.
>
Gerbils in the wild vary a lot depending on the colour of the
predominant ground colour in their location. This is sometimes called
substrate evolution. This means that even within the same species of
gerbil, the colour can vary form dark brown to golden yellow. This
happens because as well as the major mutations between say a Golden
Agouti and Argente Golden, there is the ability to have small mutations
that modify the underlying colour. For example, Mongolian Gerbils only a
few generations from the wild are not the same colour as those bred in
captivity since the 1950's.
This means that gerbils that are more yellow will be ,more likely to
survive on yellowish soils, and browner gerbils will do better on
browner soils.
www.gerbils.co.uk/gerbils/wild.htm
shows gerbils that are different the gerbils most of us have because
they are still adapted for their wild environment.
It is true that mutations that make an animal very different will
usually mean they cannot survive in their environment, but a small
change can be a great advantage.
--
Julian
[EMAIL PROTECTED]
National Gerbil Society
http://www.gerbils.co.uk/
