<span>A
big variety of organisms’ genomes have genes that control the organisms’ development
at different stages. The remains of ancestral traits usually appear at
different stages of the embryological development. For example, hair growth and
loss, the development and deformation of the yolk sac or appearance and
disappearance of gill structures in the embryo development of vertebrates.</span>
Similar patterns of embryological development provide further evidence that organisms have descended from a common ancestor. All species share a common descent, a group of organisms share common descent if they have a common ancestor. There is strong quantitative support for the theory that all living organisms on Earth are descended from a common ancestor.
