As I’ve said before, scientists commonly assert that evolution is not progressive and that organisms occupying lower branches on the evolutionary tree are not anymore primitive or ancestral than organism’s occupying higher branches, because all extant life are, as journalist Peter Knudtson stated, “equivalent cases of time-tested evolutionary success”.
For example, Harvard biologist Stephen Jay Gould wrote “evolution forms a conspicuously branching bush, not a unilinear progressive sequence…earth worms and crabs are not our ancestors; they are not even ‘lower’ or less complicated than humans in any meaningful sense.”
This web page even displays a helpful diagram of an evolutionary tree to debunk the idea of evolutionary rank:
The purpose of this post is not to convince you that evolution is progressive but rather to make a more basic point: A on the above tree should better resemble the common ancestor of A, B, C, and D, then B which should better resemble it than C or D. Many scientists disagree arguing that all four have been evolving for the same amount of time, thus all four are equally distant from the common ancestor. “Pumpkin doesn’t understand that A, B, C and D are all cousins, so one can not be ancestral to the other,” is what they’d think.
Yes they’re all cousins and not ancestors vs descendants, but precisely because C and D are cousins, you don’t know whether the common ancestor of them both better resembled C or D, and thus your best guess of what it was like is a hybrid: 50% C and 50% D.
Now what was the common ancestor of B, C and D like? Well, we already guessed that the common ancestor of C and D would be 50% C and 50% D, and so the common ancestor that this common ancestor shares with B would be a hybrid of itself and B, and thus appear 50% B, and 25% C and 25% D. Now you might say the common ancestor of B, C and D could resemble a perfect three way split between all three which is possible, but since C and D provide competing information on what their common ancestor was like, but B has a monopoly on what its ancestor was like, our best guess for what the common ancestor of all three will be skewed towards B.
Applying the same logic to the common ancestor of A, B, C and D, our best guess for what the common ancestor of all four was like, is 50% A, 25% B, 12.5% C, and 12.5% D. That doesn’t mean that really is what the common ancestor of A, B, C and D, was like, but if all we had to go by was the evolutionary tree itself, that’d be our best guess.
So as you can see, the earlier your ancestors branched off the evolutionary tree (and stopped branching), the more similar they’re likely to be to the tree’s root.
Now we don’t have to use provocative language like A is likely “less evolved” and “more primitive” than B which “less evolved” than C and D, we can merely state that A is likely “most like the common ancestor”; “most basal” and “least derived”.
Why do so many brilliant minds deny even this? I think it’s because it’s what the man on the street thinks, but he thinks it based on gut feeling, so those with better understanding enjoy explaining that “no humans didn’t evolve from apes, apes and humans are cousins.” They never bother to ask whether the layman might be right, despite his lack of understanding. It’s also part of the broader postmodern relativism that is learned in university and serves as a form of status signaling.