Joined: Oct. 2005
| 2. A mechanism that is likely to be particularly common for adding information is gene duplication, in which a long stretch of DNA is copied, followed by point mutations that change one or both of the copies. Genetic sequencing has revealed several instances in which this is likely the origin of some proteins. For example:|
* Two enzymes in the histidine biosynthesis pathway that are barrel-shaped, structural and sequence evidence suggests, were formed via gene duplication and fusion of two half-barrel ancestors (Lang et al. 2000).
* RNASE1, a gene for a pancreatic enzyme, was duplicated, and in langur monkeys one of the copies mutated into RNASE1B, which works better in the more acidic small intestine of the langur. (Zhang et al. 2002)
* Yeast was put in a medium with very little sugar. After 450 generations, hexose transport genes had duplicated several times, and some of the duplicated versions had mutated further. (Brown et al. 1998)
The biological literature is full of additional examples. A PubMed search (at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) on "gene duplication" gives more than 3000 references.
3. According to Shannon-Weaver information theory, random noise maximizes information. This is not just playing word games. The random variation that mutations add to populations is the variation on which selection acts. Mutation alone will not cause adaptive evolution, but by eliminating nonadaptive variation, natural selection communicates information about the environment to the organism so that the organism becomes better adapted to it. Natural selection is the process by which information about the environment is transferred to an organism's genome and thus to the organism (Adami et al. 2000).
4. The process of mutation and selection is observed to increase information and complexity in simulations (Adami et al. 2000; Schneider 2000).
Max, Edward E., 1999. The evolution of improved fitness by random mutation plus selection. http://www.talkorigins.org/faqs/fitness
Musgrave, Ian, 2001. The Period gene of Drosophila. http://www.talkorigins.org/origins/postmonth/apr01.html
1. Adami et al., 2000. (see below)
2. Alves, M. J., M. M. Coelho and M. J. Collares-Pereira, 2001. Evolution in action through hybridisation and polyploidy in an Iberian freshwater fish: a genetic review. Genetica 111(1-3): 375-385.
3. Brown, C. J., K. M. Todd and R. F. Rosenzweig, 1998. Multiple duplications of yeast hexose transport genes in response to selection in a glucose-limited environment. Molecular Biology and Evolution 15(8): 931-942. http://mbe.oupjournals.org/cgi/reprint/15/8/931.pdf
4. Hughes, A. L. and R. Friedman, 2003. Parallel evolution by gene duplication in the genomes of two unicellular fungi. Genome Research 13(5): 794-799.
5. Knox, J. R., P. C. Moews and J.-M. Frere, 1996. Molecular evolution of bacterial beta-lactam resistance. Chemistry and Biology 3: 937-947.
6. Lang, D. et al., 2000. Structural evidence for evolution of the beta/alpha barrel scaffold by gene duplication and fusion. Science 289: 1546-1550. See also Miles, E. W. and D. R. Davies, 2000. On the ancestry of barrels. Science 289: 1490.
7. Lenski, R. E., 1995. Evolution in experimental populations of bacteria. In: Population Genetics of Bacteria, Society for General Microbiology, Symposium 52, S. Baumberg et al., eds., Cambridge, UK: Cambridge University Press, pp. 193-215.
8. Lenski, R. E., M. R. Rose, S. C. Simpson and S. C. Tadler, 1991. Long-term experimental evolution in Escherichia coli. I. Adaptation and divergence during 2,000 generations. American Naturalist 138: 1315-1341.
9. Lynch, M. and J. S. Conery, 2000. The evolutionary fate and consequences of duplicate genes. Science 290: 1151-1155. See also Pennisi, E., 2000. Twinned genes live life in the fast lane. Science 290: 1065-1066.
10. Ohta, T., 2003. Evolution by gene duplication revisited: differentiation of regulatory elements versus proteins. Genetica 118(2-3): 209-216.
11. Park, I.-S., C.-H. Lin and C. T. Walsh, 1996. Gain of D-alanyl-D-lactate or D-lactyl-D-alanine synthetase activities in three active-site mutants of the Escherichia coli D-alanyl-D-alanine ligase B. Biochemistry 35: 10464-10471.
12. Prijambada, I. D., S. Negoro, T. Yomo and I. Urabe, 1995. Emergence of nylon oligomer degradation enzymes in Pseudomonas aeruginosa PAO through experimental evolution. Applied and Environmental Microbiology 61(5): 2020-2022.
13. Schneider, T. D., 2000. Evolution of biological information. Nucleic Acids Research 28(14): 2794-2799. http://www-lecb.ncifcrf.gov/~toms/paper/ev/
14. Zhang, J., Y.-P. Zhang and H. F. Rosenberg, 2002. Adaptive evolution of a duplicated pancreatic ribonuclease gene in a leaf-eating monkey. Nature Genetics 30: 411-415. See also: Univ. of Michigan, 2002, How gene duplication helps in adapting to changing environments. http://www.umich.edu/~newsinfo/Releases/2002/Feb02/r022802b.html
Adami, C., C. Ofria and T. C. Collier, 2000. Evolution of biological complexity. Proceedings of the National Academy of Science USA 97(9): 4463-4468. http://www.pnas.org/cgi/content/full/97/9/4463 (technical)
Hillis, D. M., J. J. Bull, M. E. White, M. R. Badgett, and I. J. Molineux. 1992. Experimental phylogenetics: generation of a known phylogeny. Science 255: 589-92. (technical)