But where is the fossil evidence? Fossils are as common as mud, and the fossil record shows stasis in species, overwhelmingly.
The problem here is noting the differences between Darwin’s finches versus the stretch and improbability over time there are changes such as the natural selection of say, antibiotic-resistant bacteria, or Darwin’s finches, in which there is a speciation based on which of a population survive in a given niche, which narrows the gene pool of the population due to isolation or killing off of the others, resulting in one prevailing, but many leaps and forming new classes involves many more steps, and higher improbability. We haven’t found everything in fossils, either, so we need the best given explanation, which is that early life is largely archaebacteria similar to what we find in the Yellowstone hot springs that live off sulfur and extreme temperatures.