Molecular Evolution: Introduction


Molecular evolution studies the mechanisms leading to present day deoxyribonucleic acid and protein sequences – it is a unifying force in biology. With the advent of the genomic era, it is expected to continue reducing the gap between molecular biology and the ecology of organisms. Some of the key advances are quantitative estimates of both the diversity in populations and of evolutionary relationships, as well as improvements in theoretical understanding. There is an improved understanding of the function of proteins and much better models of the common patterns of development. There are now powerful models for the origin of life, and at the other end of the scale, an important aspect has been the detailed models of the origin and distribution of modern humans.

Key Concepts:

  • Studies in Molecular Evolution developed very quickly once protein sequence (and then DNA sequence) information became available.

  • Molecular data inform every aspect of evolution, and similarly, molecular biology needs molecular evolution to understand it.

  • Evolutionary trees from molecular data have been, and continue to be, a major application of DNA sequences.

  • The neutral theory of evolution was an important early contribution, implying on‐going mutations occurred irrespective of any ‘need’ of the organism.

  • Gene duplication, and then divergence of the two copies, is an important source for the origin of New Information.

  • The origin of life can now be studied scientifically, and its main contribution is a proposed RNA‐world where RNA is involved in both information storage and catalysis.

  • Nothing in macroevolution has been found thus far that is not explained by normal microevolutionary molecular processes.

  • Molecular evolution shows a basic similarity of all living cells, reinforcing the common unity of all life on earth.

  • There are excellent data supporting an African origin of modern humans and spreading from there around the world (with a little introgression from earlier groups).

Keywords: complexity; continuity; DNA; evolution; evolutionary trees; human evolution; molecular biology; molecular evolution; neutralism; RNA world

Figure 1.

Repeating the duplication of the haemoglobin and divergence of the two copies gives the α and β proteins.

Figure 2.

The trichotomy problem.


Further Reading

Atkins JF, Gesteland RF and Cech TR (eds) (2011) RNA Worlds: From Life's Origins to Diversity in Gene Regulation. New York: Cold Spring Harbor Laboratory Press.

Cann RL, Stoneking M and Wilson AC (1987) Mitochondrial‐DNA and human‐evolution. Nature 325: 31–36.

Eigen M and Schuster P (1978) Hypercycle – principle of natural self‐organization. C: Realistic hypercycle. Naturwissenschaften 65: 341–369.

Golding GB and Dean AM (1998) The structural basis of molecular adaptation. Molecular Biology and Evolution 15: 355–369.

Holmes EC (2009) The Evolution and Emergence of RNA Viruses. Oxford: Oxford University Press.

Hordijk W, Mike Steel M and Kauffman S (2012) The structure of autocatalytic sets: evolvability, enablement, and emergence. Acta Biotheoretica 60: 379–392.

Jain R, Rivera MC and Lake JA (1999) Horizontal gene transfer among genomes: the complexity hypothesis. Proceedings of the National Academy of Sciences of the USA 96: 3801–3806.

Kawecki TJ, Lenski RE, Ebert D et al. (2012) Experimental evolution. Trends in Ecology and Evolution 27: 547–560.

Kehrer‐Sawatzki H and Cooper DN (2007) Understanding the recent evolution of the human genome: insights from human–chimpanzee comparisons. Human Mutation 28: 99–130.

Kimura M (1983) The Neutral Theory of Molecular Evolution. Cambridge: Cambridge University Press.

Li W‐H (1997) Molecular Evolution. Sunderland, MA: Sinauer.

Meyer M, Kircher M, Gansauge MT et al. (2012) A high‐coverage genome sequence from an archaic Denisovan individual. Science 338: 222–226.

Mossel E and Steel MA (2004) A phase transition for a random cluster model on phylogenetic trees. Mathematical Biosciences 187: 189–203.

Murray‐McIntosh RP, Scrimshaw BJ, Hatfield PJ and Penny D (1998) Testing migration patterns and estimating founding population size in Polynesia by using human mtDNA sequences. Proceedings of the National Academy of Sciences of the USA 95: 9047–9052.

Page RDM and Holmes E (1998) Molecular Evolution: A Phylogenetic Approach. Oxford: Blackwell Science.

Penny D (2005) An interpretive review of the origin of life research. Biology and Philosophy 20: 633–671.

Penny D, Foulds LR and Hendy MD (1982) Testing the theory of evolution by comparing phylogenetic trees constructed from five different protein sequences. Nature 297: 197–200.

Woese CR and Fox GE (1977) Phylogenetic structure of prokaryotic domain – primary kingdoms. Proceedings of the National Academy of Sciences of the USA 74: 5088–5090.

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Penny, David(Apr 2013) Molecular Evolution: Introduction. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0001701.pub3]