Homology (biology)

In biology, two or more structures are said to be homologous if they are alike because of shared ancestry. This could be evolutionary ancestry, meaning that the structures evolved from some structure in a common ancestor (the wings of bats and the arms of humans are homologous in this sense), or developmental ancestry, meaning that the structures arose from the same tissue in embryonal development (the ovaries of female humans and the testicles of male humans are homologous in this sense).

Related Topics:
Biology - Evolution - Bat - Human - Embryo - Ovaries - Testicle

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Homology has to be distinguished from analogy; for instance, the wings of insects and the wings of birds are analogous but not homologous. These similar structures most likely evolved through different pathways, a process known as convergent evolution.

Related Topics:
Analogy - Insect - Bird - Convergent evolution

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