Part 2) When Gould wrote this article in 1976, paleoanthropologists knew of only seven hominid species; Homo sapiens, Homo neanderthalensis, Homo erectus, Homo habilis, Australopithecus africanus, Australopithecus robustus, and Australopithecus boisei, and many assumed that these seven must all be lineall l (straight-line) ancestors of humans. Gould called this claim the “ladder” model, and criticized it because it was too simplistic. If you draw a line connecting humans to neandertals, to H. erectus, to H. habilis, to A. africanus, to A. boisei, to A. robustus, you will see a visual depiction of the supposed “ladder.” In light of the discoveries that have been made since Gould wrote, why do anthropologists no longer believe this ladder model is an accurate description of human evolution?
Part 3) Most of Gould’s predictions were pretty accurate (although older fossils of A. africanus and the even earlier A. afarensis show that the genus Homo did have Australopithecus predecessors). Now it is your turn to make a prediction. In the year 2040, will the phylogenetic tree you filled in for part 1 still be considered valid? Wiit still be considered complete? Why or why not?