According to the CK-12 Foundation:
Arguably, some of the best evidence of evolution comes from examining the molecules and DNA found in all living things.
Beginning in the 1940s, scientists studying molecules and DNA have confirmed conclusions about evolution drawn from other forms of evidence. Molecular clocks are used to determine how closely two species are related by calculating the number of differences between the species’ DNA sequences or amino acid sequences. These clocks are sometimes called gene clocks or evolutionary clocks. The fewer the differences, the less time since the species split from each other and began to evolve into different species. For example, a chicken and a gorilla will have more differences between their DNA and amino acid sequences than a gorilla and an orangutan. That means the chicken and gorilla had a common ancestor a very long time ago, while the gorilla and orangutan shared a more recent common ancestor.
But according to Stephen C. Meyer and co:
To invoke molecular analyses that presuppose a common ancestor as evidence for the existence of such an entity only begs the question. Perhaps the Precambrian rocks do not record transitional intermediates and ancestors for Cambrian animals because none existed. Citing sequence analyses that tacitly assume the existence of a common ancestor does not provide evidential support for the existence of such an ancestor. Certainly, it provides no reason for privileging molecular analyses over fossil evidence.
- CK-12 Foundation (2015). Molecular Evidence for Evolution. Available http://www.ck12.org/life-science/Molecular-Evidence-for-Evolution-in-Life-Science/lesson/Molecular-Evidence-for-Evolution/?referrer=concept_details. Last accessed 14th Mar 2015.
- Meyer, S.C. et al (2004). “The Cambrian Explosion: Biology’s Big Bang” in Campbell, J. (ed) Darwinism, Design and Public Education. Michigan State University Press, p. 366