Intelligence is likewise profoundly impacted by the degree of enrichment
experienced by the individual, and numerous studies have shown that an
early life in barren environments can produce significant reductions in
overall intelligence (among other things).  Play, complex surroundings,
intellectual tests, problem solving, sensory stimulation, memory
challenges, novelty, and even grooming can stimulate the growth of,
conserve the existence of, and strengthen the interconnections of neurons
within the brain structure, as well as their interconnections.  Both are
strongly correlated to intelligence.
 
To better understand why ferrets are they way they are, it is extremely
helpful to understand how they got here.  Part of that requires knowledge
of why they were domesticated in the first place.  In the case of
ferrets, it wasn't to go after rabbits; ferrets were probably
domesticated in southern Europe, ranging from the Iberian Peninsula
towards Turkey, possibly centered in the northern Greece and Macedonia
regions.  At the time of ferret domestication (450 BCE), rabbits were
confined to the west and central portions of the Iberian Peninsula,
making ferreting them in Greece (the location of the earliest possible
mention of the ferret) somewhat difficult.  This leaves two possibilities
for the domestication of the ferret; pest control and hunting small game
other than rabbits.  Both possibilities are probably true.  Unlike the
Egyptians who had cats to control pests attacking grain stores, southern
Europeans might have used the polecat for the same purpose, ultimately
domesticating it in time for the writings of Aristophanes, Aesop, and
Aristotle.  Also, wild hamsters and sousliks (a type of ground squirrel)
were dietary items of the time, and polecats may have been used to drive
them from their burrows.  In either case, intelligent, curious animals
would have been required, not "dumbed-down" ones.  Even if some breeders
bred for dumbness, it is unlikely that such traits would have been
preserved considering the commonality of breeding ferrets back to
polecats to improve their hunting instincts.  Such occurrences are
common enough in the literature of the last few hundred years to make
any suggestion that ferrets were dumbed-down moot; even if they were,
breeding back would have reversed the trend.  Birks, Davison et al, and
other genetics scientists have been studying the polecat genome, and have
been unable to determine the progenitor species of the ferret.  This
heavily supports the idea that ferrets have been repeatedly bred back to
polecats.  It is highly likely that the ferret is a hybrid of both the
European and steppe polecats- -at least to some degree- -and a progenitor
cannot be named.
 
"Dumbing-down" also implies some sort of genetic narrowing has taken
place.  When you bred for any specific trait, even behavioral ones, you
tend to narrow the genetic diversity of the species.  If ferrets were
dumbed-down to any real scale, there should be some degree of genetic
narrowing, but ferrets have an extremely wide range of genetic diversity.
For example, there is currently no such thing as "breeds" when it comes
to ferrets.  We may label them by their coat color, but such labels are
arbitrary and do not define a breed, such as a St.  Bernard, or a
Persian.  That means the single "breed" of ferret contains ALL the
possible variations of the species as a whole.  That is hardly indicative
of a genetic narrowing.  Therefore, because of the wide range of
variation, the lack of a logical reason why ferrets should be dumbed-down
in the first place, and the many times the species was hybridized to both
wild polecats, it is highly unlikely ferrets were bred to be less
intelligent.
 
All that said there is still the very real observation that at least the
average polecat is smarter than the average ferret.  This is a common
observation, and I believe a correct one.  However, in light of the above
discussions, the question is begged, "Are we observing differences of
nature or of nurture?" In light of the above discussion and the lack of
physically demonstrable evidence, I think it is the later.  I am
convinced that if ferrets were raised under the same conditions as wild
polecats experience (in terms of enrichment, nurturing, mother and litter
socialization, etc.), they would be just as intelligent.
 
Bob C
[Posted in FML issue 4314]