Clair writes
>We have taste buds for sugar.  We like sugar.  It is thought that
>our tasting of, and craving for, sugar is an evolutionary adaptation
>to erratic food supplies. <snip>  Other animals, such as dogs, do not
>taste or crave sugar.  There is apparently no evolutionary advantage
>to them for that trait.
>
>Ferrets like sugar.  This, to me, suggests that they have an
>evolutionary prediliction towards seeking out sweet food
 
Actually, virtually ALL mammals can taste sugar, including dogs.  The
major exceptions are domestic cats and their wild relatives.
See for example
<http://www.nature.com/news/2005/050718/full/050718-16.html>  and
<http://www.washingtonpost.com/wp-dyn/content/article/2005/07/24/
AR2005072401107.html>
 
This suggests that the predilection for sugar was an early evolutionary
trait in mammals that was lost by a common cat ancestor.  The loss
of this taste for sugar had no adverse affect on the feline, who had
evolved to become an obligate carnivore.  This is in contrast to the
more omnivorous canine species, many of which will happily munch at
ripe berries when available.
 
Ferrets, like dogs, have kept the ability to taste sugar, but
behaviorally have evolved into obligate carnivores.  You don't see wild
polecats or black-footed ferrets eating fruit.  These species may very
well have lost the ability to effectively process sugar in their diets.
 
In truth, we don't know how much sugar and other carbohydrates a ferret
can safely consume, but we do know they will do just fine with none.
 
Linda Iroff
 
International Ferret Congress
http://www.ferretcongress.org
[Posted in FML issue 5249]