|Darwin's sketch of part of the tree of life|
The point of taxonomy is to classify all organisms into a hierarchical system of relationships starting at the lowest level and working up through various levels of increasingly close relationships, ending with recognised and defined sub-species and varieties. These classifications are as man-made as are the political boundaries on maps. Simply drawing a line on a map does nothing to the land either side of that line. The geology itself is completely unaware of the line and feels no compulsion to conform to it.
Species are defined in broadly utilitarian terms and often it's a matter of differing opinion about whether this population or that is actually a distinct species, a sub-species, or a variety, and sometimes it's not clear even into which genus a species should be placed. This is even more complicated with plants where hybridization, environmental variants and polyploid varieties are common, especially in some families.
But the point is that it is humans who make these 'rules' of classification and create the groups into which we fit individual species.
Additionally, the rules were originally devised to classify living species. Life was seen as a hierarchy forming a tree-like structure with living species forming the terminal twigs of branches which were themselves branches of main boughs, all branching off a main trunk. In reality, of course, this tree is still growing and has always been growing.
Moreover, many branches don't arise abruptly but gradually diverge from each other, as we can see from the many examples of ring species and clines, so that, if we were to cut a cross-section of branch at any point in its development at different times and tried to classify it, we would see different degrees of divergence, decreasing as we go back in time and increasing as we come forward so that it would become increasingly difficult and meaningless to force any branch into one of the modern classifications. The only solution might be to create a new species into which to place it or give it a sub-specific or varietal status of its own.
If we could visualise the entire tree of life, we would see divergence occurring followed sometimes by re-uniting in some branches, or even one branch meeting and fusing with a near-neighbour. This could happen if populations of a species become isolated for a while and begin to diverge into different races, then come back into contact and interbreed freely to form a single race again, as is happening with homo sapiens today.
So, not only is classification a man-made concept with rules to which nature was not party and feels no obligation to conform but it becomes even more meaningless when used to classify earlier forms of an evolving species. Nature does not read the rule book!
This is why we can laugh at creationists when they come out with such ignorant statements about micro- and macro-evolution and get so confused about classification of ancestral forms of modern species and the supposed lack of transitional forms between a pair of randomly chosen modern species which no one in their right minds would ever expect to see because no one in their right mind would ever imagine evolved into one or the other, or between an ancestral form given the status of a distinct species and a modern form given a different one.
Of course, we can understand those under-educated simpletons who get so confused about this aspect of biology because they simply lack the ability to think for themselves. What is unforgivable is those educated pseudo-creationists (how do they know what to lie about if they don't know the truth?) who make a handsome living out of maintaining this ignorance in their target victims and supplying them with the necessary misinformation with which to pretend to know as much about biology as those who actually do, without going to the trouble of learning any.
Even more unforgivable are those who assiduously maintain their own ignorance by refusing to read anything, like this blog, which might cause them to abandon their cherished beliefs, for these are the people who are quite deliberately and consciously fooling themselves into believing what they know to be false. These will be the ones who are constantly asking what they like to think are the 'killer knock-down' questions of biologists and who then ignore the answers and ask the same questions again next week. You only need to read their sanctimonious condescension and pretence to have greater knowledge than the scientists who spend years learning and researching the subject, to see what they are getting out of their intellectual dishonesty.
I wonder if they really believe they are fooling their imaginary god by being dishonest even with themselves. No one who believes they are being watched over by an omniscient god of truth and honesty who knows our very thoughts, could conceivably believe it is being fooled by dishonesty. If this god really existed, it would be as ashamed of them as they should be of themselves.
I suppose the parasitic meme of theophobia can induce all sorts of strange irrationality in its sufferers. Once one sets off down the path of irrational belief, all manner of irrationality becomes possible, even essential, to maintain the delusion. Maybe we shouldn't expect anything better from it's victims.