In connection with the present cross, Nygren's data is of interest because the high rates of cervina and intermediate antlers in so-called moose populations suggests that hybridization between moose and elk/red deer is extensive.MADISON, Wis. However, it is inconsistent the supposition the other alternative because in the absence of hybridization the expectation is for the variation to be spatially uniform, that is, cervina antlers would be just as likely to occur in all geographic regions, whether elk were present or not. If the observed variation is due to hybridization this shift is expected because the chance of hybridizing with an elk increases toward the south as elk become more frequent. hybrid variation) in this case is Nygren’s finding that the frequency of cervina antlers increases toward the south. For example, hybrids between the polar bear and the brown bear are white at birth, but take on a yellowish-white or blue-brown coloration as they mature.Ī key fact discriminating between the two hypotheses (individual variation vs. As to the shift toward a higher frequency of cervina with age, anyone familiar with hybridization will know that, in many crosses, hybrids at a younger age more resemble one of their parents while coming to resemble the other at a later age. And they would also point out that the higher frequency of cervina antlers toward the south is an independent fact that is also consistent with that notion because elk occur at lower latitudes, on average, than moose, so southern moose populations would be more affected by hybridization with elk than norther populations. ![]() They would go on to point out that the facts that such individuals tend to be smaller is consistent with such a hypothesis because elk are smaller than moose. … The cervina type was most prevalent in the southern zone and the palmated type in the northern zone.īut how would anyone who did think in terms of hybridization interpret such results? Well, obviously, they would say that “moose” with cervina antlers are really moose-elk hybrids that tend more toward the elk end of the spectrum. At an older age, the cervina type increased and the other types decreased. At the prime age of 6.5–10.5 years, the prevalent types were intermediate and palmated. The youngest age groups were predominantly of cervina type. The cervina type had the smallest and the palmated the largest carcass weight, antler spread and tine numbers. ![]() So there is no discussion of possible hybridization. As she conceptualizes the population, it is composed of pure moose that somehow show a range of variation in their antlers from moose-like (palmate) to deer-like (cervina). alces” Nygren classified antlers into three categories palmate, cervina, and intermediate (between palmate and cervina). Palmate antlers are, at least in part, shaped like a hand, that is, there is a flat region like a palm, around the edges of which tines are attached like fingers. In Latin cervina means “of or pertaining to a deer or stag.” So describing antlers as “cervina” amounts to a fancy way of saying they look like deer antlers. ![]() Indeed, she uses the term “cervina” to designate the sort of antlers seen on the moose in the slide show at the top of this page. For example, in the present case Nygrén (2007) interpreted animals with moose-like bodies and deer-like antlers as pure moose with deer-like antlers. ![]() There is, however, a tendency among biologists to describe variation produced by hybridization as “individual variation.” Generally speaking, people who use this term leave hybridization out of account altogether, that is, they conceive of the population in question as pure (unaffected by hybridization) but variable. Ongoing hybridization, especially when the hybrids themselves are capable of producing offspring, creates highly variable populations, typically made up of individuals that are intermediate in various ways between the two parental forms that originally crossed to produce them. It is well known that hybridization produces variation. In Latin cervina means “of or pertaining to a deer or stag.” Some authors use the term cervina to refer to such antlers. The antlers of this animal are more similar to those of a mule deer ( Odocoileus hemionus) than to those of an elk ( Cervus elephas). An obvious moose-deer hybrid photographed near Red Feather Lakes, Colorado.
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