Answer: vestigial.
- A vestigial
- B homologous
- C analogous
- D entirely new
Correct answer: A. vestigial
Explanation: A vestigial organ is a reduced remnant of a once-functional structure.
A simple phylogenetic tree: a common ancestor branches into several descendant lineages over time, with each branch point marking a speciation event.
Concept context
Origin of life, Darwin's theory, natural selection, speciation, and evidence for evolution.