greg@garnet.berkeley.edu (Greg Kuperberg) (12/23/90)
What is the parent species of the domestic dog? If I understand correctly, Canis Familiaris is designated a separate species because it has a separate habitat, not because it is separated from the rest of Canis by a genetic inability to breed. Thus, there should be at least one other species with which the domestic dog can intermingle freely. Is the gray wolf such a species? Is it the sole genetic brother of the dog, or can the dog also intermingle with some other species of wolf or fox? When and where did Homo Sapiens first domesticate dogs? Please send a copy of your reply by e-mail. Thanks in advance. ---- Greg Kuperberg greg@math.berkeley.edu
szabo@crg5.UUCP (Nick Szabo) (01/06/91)
In article <1990Dec23.055209.7722@agate.berkeley.edu> greg@math.berkeley.edu writes: >What is the parent species of the domestic dog? If I understand correctly, >Canis Familiaris is designated a separate species because it has a separate >habitat, not because it is separated from the rest of Canis by a genetic >inability to breed. Is the definition of species "genetic inability to breed" or "practical inability to breed"? I doubt a chihuahua (assuming it could survive in the wild) would mate with a wolf, regardless of genetic or developmental compatability. -- Nick Szabo szabo@sequent.com "If you want oil, drill lots of wells" -- J. Paul Getty The above opinions are my own and not related to those of any organization I may be affiliated with.
alanm@hpindda.cup.hp.com (Alan McGowen) (01/11/91)
>Is the definition of species "genetic inability to breed" or "practical >inability to breed"? Mayr defines the "biological species concept" as follows: _Species are groups of interbreeding natural populations that are reproductively isolated from other such groups._ (Ernest Mayr, _Populations, Species and Evolution_, Harvard 1970) Closely related species may be interfertile to some degree. The key point is that they do not in fact interbreed in the wild -- no gene flow occurs between the groups -- regardless of what might be accomplished by way of laboratory crosses. If a population is reproductively isolated for a long enough time, enough genetic differences will accumulate for it to be considered at least a separate subspecies. This is so even if there are no obvious morphological differences (as is the case e.g. in the Mount Graham red squirrel). If after the reproductive barrier is removed the group no longer interbreeds with the parent group you have a new species. Usually the cause of the reproductive barrier is a geographical separation from the parent group. Speciation by this route is called _allopatric speciation_. _Sympatric speciation_, in which the new species develops in the same geographic area as the parent group, is more rare. In practice species and subspecies designations are often based on morphology rather than on genetics. This is why it can happen that two designated species (designated on morphological grounds) are discovered to interbreed in nature, so that in fact there is one polymorphic species. Conversely, geographically separated subspecies may be elevated to species status if evidence accumulates that the genetic difference between them is large enough to warrant it. >Nick Szabo szabo@sequent.com ---- Alan McGowen alanm@hpindbu.cup.hp.com