The ideas of Ernst Haeckel, in his youth a hardline Darwinian materialist, were to evolve to a surprising degree.
The authors considered human evolution especially important, because they believed it supported their vision of racial inequality.
What about the objection that Darwinism, properly understood, doesn’t support scientific racism (much less Nazi racism)?
Common ancestry does not emerge from the inconsistent findings of molecular phylogenetics.
I’ve watched many Khan Academy videos over the years — sometimes just for fun, and sometimes to advise teachers on whether they are good tools to use.