ARDS What happened during the Cambrian explosion? A Dinosaurs went extinct. a B Many animals first appeared. c Single-celled life first appeared. D Humans first appeared.

Scientific thinking: what clues about biology might road kill provide?

The wings of insects, birds, and bats evolved independently but carry out similar functions. this is an example of a. analogous structures. b. embryonic structures. c. vestigial structures. d. homologous structures.

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.