Powstawanie, rodzaje i rola zmienności w ewolucji
Variation - sources, types and role in evolution
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Genetic variation among individuals within a population concerns both quantitative and discrete traits and manifests at a variety of organizational levels, from whole organisms down to chemical constituents of cells. The results of DNA sequencing revealed even more variation than was detected by earlier comparisons of proteins by gel electrophoresis. The observation of unexpectedly high levels of genetic variation in both coding and the non-coding regions of DNA led to development of the neutral theory which holds that most variation at the molecular level does not affect fitness and can be accounted for by stochastic processes. A relatively constant rate of molecular evolution - the molecular clock - provided it is properly calibrated, became a useful method of estimating the time of events in evolutionary history. While mutations are the ultimate source of genetic variation, the major source of differences among sexually reproducing individuals in populations results from meiotic crossing over, recombination of chromosomes and random fertilization. Since recently, high throughput sequencing methods provide new insights into the evolution of genomes revealing major contributions from gene and whole genome duplications, large deletions and horizontal transfer of genes. The uncovering of the mechanisms responsible for epigenetic phenomena in plants and animals and the observations of transgenerational epigenetic inheritance (i.e. inheritance not dependent on changes in the sequence of DNA) opens the way to study the importance of multigenerational epigenetics for evolution and adaptation.
- Ayala F. J., Kiger J. A., 1984. Modern Genetics. Benjamin/Cummings Publishing Co. Menlo Park, CA.
- Hahn M. W., Demuth J. P., Han S. -G., 2007. Accelerated rate of gene gain and loss in primates. Genetics 177, 1941-1949.
- Jablonka E., Lamb M. J., 2005. Evolution in four dimensions. MIT Press. Boston MA.
- Jablonka E., Raz G., 2009. Transgenerational Epigenetic Inheritance: prevalence, mechanisms and implications for the study of heredity and evolution. Quart. Rev. Biol. 84, 131-176.
- Kimura M., 1968. The neutral theory of molecular evolution. Nature 217, 624-626.
- Kimura M., 1991. Recent development in the neutral theory viewed from the Wrightian tradition of theoretical population genetics. Proc. Natl. Acad. Sci. USA 88, 5969-5973.
- Koonin, E. V., 2009. Darwinian evolution in the light of genomics. Nucl. Acids Res. 37, 1011-1034.
- Lynch M., 2007. The origin of genome architecture. Sinauer Associates, Sunderland, MA.
- Ohno S., 1970. Evolution by gene duplication. Springer-Verlag, Berlin.
- Prabhakar S., Visel A., Akiyama J. A., Shoukry M., Lewis K. D. i współaut., 2008. Human-specific gain of function in a developmental enhancer. Science 321, 1346-1350.
- Zuckerkandl E., Pauling L., 1965. Evolutionary divergence and convergence in proteins. [W:] Evolving Genes and Proteins. Bryson V., Vogel H. J. (red.). Academic Press, New York, 97-166.
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