Molecular Evolution

Molecular evolution is the area of evolutionary biology that studies evolutionary change at the level of the DNA sequence. It includes the study of rates of sequence change, relative importance of adaptive and neutral changes, and changes in genome structure. For evolutionists the revolution in DNA technology has been a major advance. The reason is that the very nature of DNA allows it to be used as a “document” of evolutionary history: comparisons of the DNA sequences of various genes between different organisms can tell us a lot about the relationships of organisms that cannot be correctly inferred from morphology. One definite problem is that the DNA itself is a scattered and fragmentary “document” of history and we have to beware of the effects of changes in the genome that can bias our picture of organismal evolution.