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Evolution

Question
CBSEENBI12047062

The early stage human embryo distinctly possesses

  • gills

  • gill slits

  • external ear (pinna)

  • eye brows

Solution

B.

gill slits

Both chick and human embryos go through a stage where they have slits and arches in their necks like the gill slits and gill arches of fish. These structures are not gills and do not develop into gills in chicks and humans, but the fact that they are so similar to gill structures in fish at this point in development supports the idea that chicks and humans share a common ancestor with fish. Thus, developmental characters, along with other lines of evidence, can be used for constructing phylogenies.