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A bit of history. The idea No.1 was to classify the species into the "kinds", like Russian dolls. But, when it was done, we understood that actually, all the species were on the same tree. 200 years latter creationists are wondering about the kinds... But immediately after it was shown that there is no clear number of classes of animals. So instead of species, genus, family... we ended up with all imaginable sub-, between-, uber- classes. Next problem emerged when we understood that some species got the genes not "vertically" from the parents but also "horizontally" from other unrelated species. We currently have about 5.000 genomes of eukaryotes. It is still expensive to do for every species but the prices are falling fast. For the individual species, like the dogs, there are developed kits, but for some obscure animals - there is not. https://steemit.com/science/@alexs1320/family-tree-of-the-dogs-from-2017 And the biggest problem is that, believe it or not, there is no clear definition of the species.