Has microevolution actually been observed?

Yes, it has. It has been observed both in the lab and in nature. It would be impossible to list all confirmed examples of microevolution, but here are a few.

1. Bacteria have acquired resistance to viruses [Luria, S. and Delbruck, M. (1943) "Mutations of bacteria from virus sensitivity to virus resistance." Genetics 28: 491-511.].

2. Bacteria have developed resistance to antibiotics as well [Lederberg, J. and Lederberg, E. M. (1952) "Replica plating and indirect selection of bacterial mutants." Journal of Bacteriology 63: 399-406.].

3. Bacteria have also developed the ability to synthesize new amino acids and DNA bases [Futuyma, D. (1998) Evolutionary Biology. Third edition. Sunderland, MA, Sinauer Associates, p. 274].

4. Bacteria have also developed the ability to grow at temperatures that initially killed the population [Bennett, A. F., R. E. Lenski, et al. (1992) "Evolutionary adaptation to temperature. I. Fitness responses of Escherichia coli to changes in its thermal environment." Evolution 46: 16-30.].

5. In E. coli, we have observed by artificial selection the development of an entirely novel metabolic system including the ability to metabolize a new carbon source, the regulation of this ability by new regulatory genes, and the evolution of the ability to transport this new carbon source across the cell membrane [Hall, B. G. (1982) "Evolution on a petri dish: The evolved b- galactosidase system as a model for studying acquisitive evolution in the laboratory." Evolutionary Biology 15: 85-150.].


6. Protistans have developed the ability to use nylon and pentachlorophenol (which are both unnatural manmade chemicals) as their sole carbon sources [Okada, H., S. Negoro, et al. (1983) "Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers." Nature 306: 203-206. ; Orser, C. S. and Lange, C. C. (1994) "Molecular analysis of pentachlorophenol degradation." Biodegradation 5: 277-288.].

7. Insects have been observed to become resistant to insecticides [Ffrench-Constant, R. H., N. Anthony, et al. (2000) "Cyclodiene insecticide resistance: from molecular to population genetics." Annual Review of Entymology 45: 449-466.].

8. Animals and plants have been observed to acquire disease resistance [Carpenter, M. A. and O'Brien, S. J. (1995) "Coadaptation and immunodeficiency virus: lessons from the Felidae." Current Opinion in Genetics and Development 5: 739-745.; Richter, T. E. and Ronald, P. C. (2000) "The evolution of disease resistance genes." Plant Molecular Biology 42: 195-204].

9. Crustaceans developed new defenses to predators [Hairston, N. G., Jr. (1990) "Fluctuating selection and response in a population of freshwater copepods." Evolution 44: 1796-1805.].

10. Amphibians develop tolerance to habitat acidification [Andren, C., M. Marden, et al. (1989) "Tolerance to low pH in a population of moor frogs, Rana arvalis from an acid and a neutral environment : a possible test case of rapid evolutionary response to acidification." Oikos 56: 215-223.].

11. Mammals acquire immunity to poisons [Bishop, J. A. (1981) "A neo-Darwinian approach to resistance: Examples from mammals." In Genetic Consequences of Man Made Change. J. A. Bishop and L. M. Cook. London, Academic Press.].

These kinds of experimental observations show us that species can adapt and change readily to variations in their environment, which is a testament to the design ingenuity of the Almighty. What ALL of these changes have in common is that they are changes WITHIN a given genetic code. So far, there has been no observation of changes OUTSIDE of a genetic code.

Tags: Biology
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2019-02-05 21:42
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