Scientists compare the structures of a chicken embryo and a human embryo at the same stage of development. They find that both vertebrates have similar shapes and structures, including the presence of gill slits and tails. How is this comparison of the embryos used as supporting evidence of evolution? A. The similarities suggest that chickens and humans are the direct descendants of modern-day fish with tails and gill slits.
B. The similarities suggest that vertebrates pass through each of the adult stages of their evolutionary history as they develop.
C. The similarities suggest that vertebrates can undergo genetic changes during development that lead to the evolution of new species.
D. The similarities suggest that chickens and humans descend from ancestors with genes that code for the development of tails and gill slits.