That's a bit of a human trait, categorizing things. It's not like evolution decides to suddenly have a new species, it's by definition liquid, generation for ge

That's a bit of a human trait, categorizing things. It's not like evolution decides to suddenly have a new species, it's by definition liquid, generation for generation. The fact that there are many more clearly defined species is because "fitness" (which sometimes includes very random events happening) results in many "species" (or sub-species or variants or groups of mutants) to die out eventually and one lucky/fit group to survive. With homo sapiens, like with many other only recently established species that didn't really happen. Or well, it did and that's why we have that taxonomy problem. But you can draw all sorts of lines. Of course the whole race topic comes in there too and what about people who are able to drink milk after a certain age and those who don't. Species are sometimes distinct by very minor traits like that and not always by being able to have offspring. So decisions are either made by people who establish species or by a majority of scientists agreeing, so more or less through a political rather than a scientific process. Of course that means it comes to a lot of bike shedding on these topics. It's more a discussion about what the definition of the word species is than anything else.