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[–] ditch-digger 0 points 2 points (+2|-0) ago 

The genetic difference between black and white is greater than the difference between black and chimpanzee.

Wish I had saved the source of that bit. But race is a specialized term for species, the only other word we use like it is breed.

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[–] jxfaith ago  (edited ago)

Breed is more accurate than species here. Best definition I can come up with for breed is a set of geographically concentrated traits, often distinguishable by visual qualities. Think dogs: coloration, face shape, hair color, stature.

The major scientific requirement for speciation is sexual isolation: distinct species cannot reproduce between their populations. Highly similar populations can often reproduce but yield sterile hybrids. Considering the viability of mixed-race offspring among humans, it's inappropriate to consider other races as different species.

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[–] ditch-digger 0 points 2 points (+2|-0) ago  (edited ago)

Incorrect.

http://rafonda.com/interbreeding_between_species.html

The biological species concept was developed by Ernst Mayr, in 1942. Here it is, as first formulated, and quoted in Douglas J. Futuyma's EVOLUTIONARY BIOLOGY (1998): "Species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups". The "reproductive isolation" can be genetic (non-fertility), geographic, or behavioral; there is NO criteria that says (as is commonly believed) that if two populations can interbreed they are the SAME species. There is NO criteria that says that two distinct species CAN'T interbreed. Consider the example of wolves, coyotes and dogs: three distinct species that can interbreed. In fact, all species of the genus Canis can mate and produce fertile offspring (Wayne et al., 1997, re: A. P. Gray, Mammalian Hybrids). This is so common, that biologists actually use a different formulation of Mayr's definition: they say, "If two populations can NOT interbreed, they are NOT the same species." That is a very different statement. Note that this is an empirical definition, and gives no guidance in regard to extinct taxons, but the bottom line is: nothing in the biological species concept contradicts the idea that erectus and sapiens could and DID interbreed

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[–] kittysaysmeownow ago 

explain the Liger then.