The evolution of new organs usually builds on preexisting structures that are modified in form and sometimes function.The embryos of fish,amphibians,reptiles,birds,and mammals all have pharyngeal pouches or gill slits.These pouches develop into gills in adult fish and they are used to absorb oxygen from their watery environment.These same pouches become parts of the ________ in humans.

Question

Quizplus · Accepted Answer

The pharyngeal pouches in human embryos develop into parts of the ear and throat, specifically the middle ear, eustachian tubes, and tonsils. They do not develop into lungs, heart, eyes, or nose.

The Evolution of New Organs Usually Builds on Preexisting Structures