XXVII.2.1 Paleontological finds show that individual monophyletic taxa have appeared gradually on the Earth, in the order that corresponds to their relationship deduced on the grounds of similarity
Paleontology, the study of fossils, provides us with a great deal of evidence for the simple fact of evolution.However, the existence of fossils is not, in itself, evidence for evolution.Nonetheless, because of the possibility of dating fossils using a number of physical methods, at the very least it reliably overturns the ideas of some opponents of evolution about the recent emergence of animals, plants and humans on the Earth approximately 6000 years ago.While there are not now a great many proponents of the “Young Earth” theory, relying on a literal interpretation of the Bible, they are disproportionately vociferous.However, the results of stratigraphic analysis document the evolution of organisms from a common ancestor, showing that the individual organisms do not appear in the paleontological record at random, but rather in the order that corresponds to their mutual similarity and thus assumed relatedness.On the basis of the similarity of the members of the main taxa of vertebrates – fish, amphibians, reptiles and mammals – it can be concluded that they were most probably formed one from another in this order.Theoretically, it would also be possible that they would be formed from one another in the opposite order, i.e. that first mammals would be formed, from them reptiles, then amphibians and finally fish.However, this possibility can be refuted by comparison of fish and mammals with invertebrate fauna, which certainly have far more common traits with fish than with mammals.Perusal of the paleontological record reveals that, of these groups, fish actually did appear first on the Earth, followed by amphibians, reptiles and finally mammals.The same analysis can be performed in any monophyletic taxon, i.e. within a group of organisms for which it can be assumed, on the basis of independent data, that they evolved from a common ancestor.In every case, we obtain results that are in full agreement with the predictions made on the basis of the theory of evolution.This indicates that the individual groups of organisms emerged gradually over time through divergence from a common ancestor.