Q: I was looking at the photos of the blackfoot ferret and wondered if
   our ferret was domesticated from it?  They look a lot alike .
 
A: I have the same problem I look a lot like a dweeb, but I am not of the
   dweeb species.  I am a nerd and proud of it.
 
I ll give you the answer in two versions: short and long.  You may not
like it, but you probably don t like potato chips on bologna sandwiches
either, and I do.  ;-p
 
There are four species of polecats: the European polecat (Mustela
putorius), the steppe polecat (M. eversmannii), the black-footed ferret
(M. nigripes), and the domesticated ferret (M. furo).  Ok, maybe five:
modern studies suggest the European mink (M. lutreola) may be a polecat,
but we will ignore that issue for this discussion.  Together, they form
the subgenus Putorius within the Mustela.  At this point in time, the
four are considered distinct, extremely closely related species.  No one
knows for sure if the ferret was domesticated from the European or steppe
polecat or both, but it is fairly apparent the black-footed ferret was
not part of the process.  In short, the BBF and the ferret look a lot
alike because they are so closely related, however, the ferret was not
domesticated from the BBF.
 
Catch your breath, cause here is the longer version.  Current genetics
work cannot distinguish which polecat was the ancestor of the ferret.
Part of this is because of the habit of introgression, the hybridization
of ferrets with polecats to improve hunting or pelt qualities.  This has
been going on for centuries (maybe millennia), probably with both types
of polecats, and it has so confused the genetics that the true progenitor
may never be discovered.  It is possible the ferret was domesticated from
the steppe polecat, but years of introgression to the European polecat
have confused the issue.  It is possible the ferret was domesticated from
the European polecat, but introgression to the steppe polecat has
obscured things.  It is possible the ferret was domesticated from both
polecats, and when interbred at a later time the origins were befuddled.
It is also possible the steppe polecat had no involvement and it is just
the close relationship to the European polecat that is mystifying the
genetics.  We may never know the wild ancestor of the ferret, at least
with current technology.  This is why the correct scientific name for the
domesticated ferret is Mustela furo.
 
The ferret is certainly a polecat, but which one?  Which brings up
another point.  What is the correct number of species of polecat?  If you
exclude domesticated species, are there three polecats (BBF, European,
steppe)?  If you include the European mink, are there four?  If you
listen to listen to paleobiologists and geneticists who suggest the BBF
is only a subspecies of the steppe polecat, are there only two species,
three with the European mink?  The chromosomal differences (karyotype)
between the polecats are not in the genome (genetic differences), but in
the number of chromosomes; M. putorius and M. lutreola are 2n=40, M.
eversmannii and M. nigripes are 2n=38.  The difference in number is
caused by a single Robertsonian rearrangement, which (simplistically)
means the chromosomes have been shuffled a little, but there is no real
difference in the genetic information.  All these species can breed and
produce viable, fertile offspring.  What if the genetics work suggests
the European mink is a subspecies of the European polecat, the BBF is a
subspecies of the steppe polecat, and both polecats, despite a minor
difference in karyotype, are a single worldwide (Holarctic) species?
 
If that were actually the case, then the polecats would be a single
species and would collectively represent the ancestor of the domesticated
ferret.  If that scenario ever turns out to be true (and it might!), it
would be a nightmare for the CaCaLand Fishing Gestapo.  It would mean the
domesticated ferret and the black-footed ferret were the same species.
Can you imagine the residents of California suing the CFG to get federal
protection for their floor monkeys because of the endangered species act?
 
Bob C
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[Posted in FML issue 4566]