I had a wildlife biologist tell me today that black squirrels are a result of inbreeding. We seem to have pockets of black squirrels here in the southern Adirondacks, but no great numbers of them. I read in the archives that Michigan is loaded with them, so the melanistic explanation might not be true for places like that. Another person said that he saw black squirrels around parks and not in the woods. Maybe inbreeding would be more likely to take place where squirrels are confined. Does anyone else have an opinion on this phenomenon? The biologist also showed me how to age a deer, which was quite interesting.
Return to Lifesize Mammal Taxidermy Category Menu
I think your bioligist is not to smart.
There are many sites on the internet about this.
The black gene is a dominate gene. Horse cattle, hogs even down to cats and dogs, rats and mice. Having at one time raised all of the above and bred for color and trainability.
Take a black cow breed to a hereford bull, the results is 98% that you will have a calf that is a black baldy, i.e. white face with black body.
Same with many horses, its called Homozygous, many spotted stallions will throw spotted foals even when bred to a solid linage of sorrel mares.
I have raised cats and dogs the same way.
Also at one time have raised snakes, I had several breeding pairs of rats and mice, it works the same as larger animals.
Do a bit of research and take it back to the bio. and have some questions ready for him!
They are quite proud of their pretty black squirrels that reside in town.
Homozygous does NOT equal dominant.
Homozygous means "purely inheriting". This means the gene is inherited in pure form, i.e. not "split" for anything.
Dominant means that the gene will express itself "first" or "above" other mutations. You can not be "split" for a dominant mutation.
Heterozygosity is the state of being split for something.
A recessive gene can lie hidden for aeons because it is always masked by a dominant gene.
The biologist MAY be correct in that local populations of animals with small territories may breed together without an outcross for a long time. That is more due to sheer size of animals and territory size or movements of the population, than strict "by choice inbreeding". Think of Darwin's finches. If the population becomes genetically isolated "like on an island", then the mutations (either dominant or recessive) may begin to show up.
The definitive test is to catch a bunch of the squirrels and have all their DNA analyzed for relatedness. That will determine inbreeding coefficient, moreso than any biologist or crack dog breeder's opinion.
Gray squirrels all carry the recessive gene for the 'grey' colour and they also carry the dominant "black" colour gene. When you have inbreeding in small isolated populations you can do get a population showing primarily the dominant trait...or you can get the opposite and have a bunch of grey coloured gray squirrels (think also of mainland Black bears and Kermode bears). All you have to do is add an unrelated individual into the gene pool to mix things up again until once again the gene traits settle out and you get a single-colour-dominated population.
In the case of gene mixing, because the black colour is dominant, you will only get about 1 in 4 grey coloured gray squirrels (in a perfect world with both breeders have similar genetic patterns). In this case you will get 1 black homozygous, 2 black heterozygous and 1 grey homozygous offspring...wahla...you are both bang on with your posts...isn't it nice when we all get along...LOL...
we have quite a few of those black squirrels in higginsville MO. only on my side of town though. they have been around for many years here. an old man brought one in and they bread from there. now i see them daily. i have some in my freezer and some on the wall from road kill
Genes in a strand are in pairs. Homozygous, Means that both genes in the pair are Identical. For example A Homozygous paint stallion will have both color genes in the string for the paint gene. Since the Tobiano gene is a dominant gene. the get from such a stallion will Always be painted. Because even if he receives a non painted gene in his color string from the dam. the paint gene will show dominants. However a non Homozygous stallion may pass on the recessive non paint gene from his color string. thus when bred to a solid color mare the Paint pattern may not appear. Since the foal receives one gene from each parent. Thus If a foal shows no Tobiano paint pattern. even if its parents were painted. He, or she will never produce painted offspring, unless bred to a painted partner. Now since Black is also a dominant gene. Any animal possessing a black gene will be black. However a black parent bread to a gray partner may produce a gray offspring. Unless the black parent is Homozygous. It is even possible for two black parents to produce a gray offspring. If neither is Homozygous.
Now if we look at most black Squirrel populations closely we will see that they are not truly black. But a variation in some form of dark gray. Usually containing red and white hair. Understanding that forms of gray are recessives we can see that Isolated populations of black squirrels, dose come from in breeding in a since but the scope of the inbreeding that consolidates the black trait. may take generations to encompass an existing population. Research At Kent State university In the 30s indicates that the black, or dark gray trait in squirrels appears to take dominants over the gray trait. So a single squirrel with a Mutated black trait. Could over a period of time have an impact on the entire population in an area. this seems to indicate that one day. The gray squirrel as we presently know it. will no longer exist in North America.
Homo= same As in homosexual (same sex)
Hetero= different As in heterosexual (different sex)