do all homologous structures have common ancestor?explain i think the answer is no.because birds have emerged from dinosaurs and humans from ape,so they don`t have common ancestors.forelimbs is their homologous structure. my answer right or wrong?

Asked by my3shyll | 3rd Feb, 2017, 07:44: PM

Expert Answer:

Homologous structures are very similar in skeletal structure. More significantly, they are derived from the same structures in the embryo. Structures that are embryologically similar, but have different functions, are called homologous structures. Though these animals look different, a comparison of homologous structures indicates that they are quite similar. This suggests that these animals evolved from a common ancestor.
It is important to note that defining two structures as homologous depends on what ancestor is being described as the common ancestor. If we go all the way back to the beginning of life, all structures are homologous!

Answered by Sivanand Patnaik | 4th Feb, 2017, 05:52: PM

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