One the key pieces of evidence for the "fact" of common descent of species through natural selection (plus some other assortment of mechanisms).
So, how accurate was our picture of the relationship of animal kinds based on morphology (looking at bones, organs, and tissues)? The degree to which the fact of evolution is supported is supposedly measured by similarity of the tree of life before the flood of genomic DNA data to the tree of life based on genetics (i.e. a "parsimonious" tree of life that poses the fewest problems for a common descent narrative).
Here is one such comparison:
Tree changes: Cnidarians (jellyfish) are actually more genetically similar to the more complex animals than ctenophores (comb jellies) even though they appear simpler (fewer morphological innovations). Therefore, because of molecular studies, they are now assumed to have arrived later than jellyfish. At least two groups of morphological deuterostomes are now thought to have much closer relationship to the other protostomes than to the chordates (vertebrates, tunicates) and starfish. All the explanatory help of lumping the arthropods with the segmentally organized annelids (earthworms) is gone; instead, insects are closer to the simpler nematodes, and earthworms are more like molluscs (snails, squids) genetically. Platyhelminthes (flatworms) are a significantly later development than previously thought. Rotifers are closer to flatworms now than to roundworms, and the same goes for earthworms.
The only way that this confirms the tree story is that, loosely speaking, there is a correlation of morphological similarity and genetic similarity, which would be expected they are alike because of shared design or because of "descent with modification." Only we weren't expected so much reworking of the trees assuming descent with modification.
What about more recent evolutionary developments, such as mammal evolution? Does it fare any better? Here is a picture from a site specifically attempting a knockdown presentation of the "fact" of common descent:
These trees don't even come close to showing all the disparities. Three groups previously thought to be various types of insectivores have been transported to remote parts of the mammal tree. Bu you can still see that carnivores have been radically re-filed, and so have pangolins. Cetaceans do not even appear in the 2nd tree (disappeared along with the bats--once thought more similar to primates--and hyraxes, which remained close to the elephant), so we don't see how things have changed there--they didn't move next to the anteater as did the elephant. The kind of shrew insectivore pictured in the trees has moved from away from the carnivores and next to the primates!
Really, folks, just some minor tweaks to the ol' tree!!! Somehow it is claimed that the "basic structure of the two trees . . .[a]re not actually that different"! Basically, to disprove common descent, there would have to be almost no correlation at all between morphological similarity and genetic similarity. Surely, a supernatural Designer would not have allowed any general correlation between morphological similarity and genetic similarity if he expected us to draw some conclusion other than common descent? Such has been the "one long argument" since 1859.
Yet another example of the predictive success of evolutionary theory:
Evolutionary theory has CRUSHED IT again! Woot! Woot!
Because it's a theory as "well supported as the theory of gravity." Yup.
In the evolution post, the title of part 7 unintentionally provides an amusing caption for the tree figures: