The common ancestor of humans and the other "great apes" walked on all fours, while humans are bipeds. Bipedalism is thus the _______ trait.
A) ancestral
B) homoplasic
C) synapomorphic
D) derived
E) monophyletic

Question

Quizplus · Accepted Answer

Bipedalism is a derived trait that is unique to the human lineage and was not present in our common ancestor with the other great apes. An ancestral trait is one that was present in the common ancestor of a group of organisms, while a synapomorphic trait is a shared derived trait that evolved in the common ancestor of a group of organisms and is present in all of its descendants. Homoplasic traits are those that evolved independently in different lineages, often due to convergent evolution. Monophyletic refers to a group of organisms that includes an ancestor and all of its descendants.

The Common Ancestor of Humans and the Other "Great Apes