>>14319833Hybridisation is another problem with the standard concept of a species, as would
>>14318899 be if that ever actually occurs. Also, you can point out that there are "mechanical" barriers to reproduction, e.g. peepee too big/small, yet artificial insemination is possible.
The concept of a species is really only useful when we talk about what happens in nature, not when humans fuck around as much as possible with organisms. What we mean by "species" is a population or set of populations of organisms which have similar characteristics and behaviours, can breed to produce fertile offspring, and actually tend to exist in stable niches with somewhat stable genomes. Because ligers and tigons can only breed with more lions/tigers, not with themselves, they don't really class as species, but as hybrids.
There really isn't a complete, concrete definition of "species" like there are definitions for mathematical or physical concepts, just good descriptions which cover almost all cases.
