>>12934889>Two organisms with sufficiently different characteristics that are observable are different species.Retard-tier take. This is a vague definition. Organisms of the same species can respond very differently to identical stimuli. I mean that's literally why different phenotypes exist within a single species. Some differences between organisms will be relevant for differentiating between species, and other features wont be. Unless you've provided some explicit criterion to distinguish between relevant differences and irrelevant differences, then you're definition is useless.
More generally speaking, your claim is a tautology. It says nothing. Whenever we distinguish two subgroups of a population, where we are talking about domains, kingdoms, phyla, clades, genuses, species, subspecies, or even simply SNPs, we're distinguishing between both groups on the basis of some observable difference, whether it be genotypic or phenotypic. Actually, the same can be applied to literally anything. House are different from car, are different from volcanoes, which are different from galaxies all because of the observable differences between them, but that doesn't tell us anything helpful or useful about these categories of objects. So obviously, different species of bacteria are going to be identified as different, in virtue of the fact that they display some detectable difference, but if you can clearly articulate what sort of difference would be relevant, then you haven't told us anything. People, for instance, differ in height, blood type, and many other features, but we're all member of the same species. Simply being "different" is not a sufficient condition for two organisms to belong to different species. Using the phrase "sufficiently different" does not solve the problem, because "sufficiently different" doesn't actually specify an unambiguous criterion for us to use.
