Giraffes May Be Six Separate Species

The BBC reports on research, published in BMC Biology, pointing to the possibility that there may be at least six species of giraffe in Africa. Quoting: "'Using molecular techniques we found that giraffes can be classified into six groups that are reproductively isolated and not interbreeding,' David Brown, the lead author of the study and a geneticist at... UCLA told BBC News. 'The results were a surprise because although the giraffes look different, if you put them in zoos, they breed freely.'"

Comments

Breeding?

[FroBugg]

Although the giraffes look different, if you put them in zoos, they breed freely.

Assuming they produce viable offspring, isn't that one of the primary definitions for a single species?

Re:Breeding?

[shellbeach]

wouldn't it be better to say 6 subspecies of giraffe? IAAB, and yes, that's absolutely correct. They're subspecies.

You get the same thing with the house mouse, mus musculus -- subspecies that are genetically distinct and geographically isolated, but which will interbreed in captivity (and in bordering zones in the wild). It's presumed that a lower fitness in the offspring of cross-subspecies matings in bordering zones keeps the subspecies separate.

Re:Contradiction?

[ferd_farkle]

Reproductive isolation is a major characteristic of speciation. Lions and tigers, horses and donkeys, etc are different species, but under unnatural conditions may mate and even produce offspring. Depending on how unrelated the species are, the offspring may or may not be viable.

Speciation is not as cut-and-dried as you might think. Reproductively isolated populations diverge more and more over time, and the speciation becomes more and more pronounced.