Wednesday, August 24, 2011

Vestigial Organs

Vestigial organs are structures in the body that are no longer important to the organism. In other words, the body can function normally without them. This is why we can remove several things from the body such as the appendix, tonsils, adenoids, wisdom teeth and others without causing harm to the body. However, long ago these organs did have important functions to our ancestors. It would be useless to provide blood, space and nutrients to organs that no longer are important, so natural selection favors individuals with reduced versions of the organs and tends to phase out obsolete structures. Changes in patterns of gene expression while embryos involve structural changes. Changes in an organism's embryonic development from natural selection are represented by vestigial organs.

Depicted below is a vestigial organs called "Darwin's point of ear" on a human. Long ago these were used by our ancestors but now it does not hold an important function to us anymore.



Works Cited:
Campbell, Neil, Jane Reece, and Lawrence Mitchell. “Controlling the Internal Environment.” Biology. Fifth ed. Menlo Park: Jim Green Publishing, 1999. 866. Print.

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