Genetics and Molecular Biology

How can molecular biology be used to trace the process of evolution?

The most troublesome “missing information” for Darwin had to do with heredity. Darwin had no idea how heredity worked, and he was deeply worried that this lack of knowledge might prove fatal to his theory. As it happens, some of the strongest evidence supporting evolutionary theory comes from genetics. A long series of discoveries, from Mendel to Watson and Crick to genomics, helps explain how evolution works. At the molecular level, the universal genetic code and homologous molecules provide evidence of common descent. Also, we now understand how mutation and the reshuffling of genes during sexual reproduction produce the heritable variation on which natural selection operates.

Life's Common Genetic Code One dramatic example of molecular evidence for evolution is so basic that by this point in your study of biology you might take it for granted. All living cells use information coded in DNA and RNA to carry information from one generation to the next and to direct protein synthesis. This genetic code is nearly identical in almost all organisms, including bacteria, yeasts, plants, fungi, and animals. This is powerful evidence that all organisms evolved from common ancestors that shared this code.

Table of Contents