The diagram shows embryo development of four different animals. how is this evidence used to suggest that life changes over time? a. lack of homologous structures in later stages of embryonic development indicate that each species is unique, and a common ancestor is unlikely. b. similarities in embryonic development prove that vestigial structures are common to all species, and life has changed very little over time. c. when there are physical similarities in the early stages of embryonic development, it suggests that each of the modern organisms once had a common ancestor. d. the genetic inheritance of each of these species is exactly the same in the early stages of development but then changes as the embryo grows and develops over time.