Claim CB150:

Evolution requires that protein sequences change to very different sequences, with all the intermediate sequences staying functional. But out of all possible sequences, functional sequences are extremely rare, so most functional sequences are highly isolated from each other. Using language as an analogy, one sentence cannot be changed to another by gradual changes such that all the intermediate changes are meaningful. It is highly improbable that random mutations could change one functional sequence to another.

Source:

Meyer, Stephen C., 2004. The origin of biological information and the higher taxonomic categories. Proceedings of the Biological Society of Washington 117(2): 213-239.

Response:

  1. Functional sequences are not so rare and isolated. Experiments show that roughly 1 in 1011 of all random-sequence proteins have ATP-binding activity (Keefe and Szostak 2001), and theoretical work by H. P. Yockey (1992, 326-330) shows that at this density all functional sequences are connected by single amino acid changes. Furthermore, there are several kinds of mutations that change multiple amino acids at once. A simulation of duplication and divergence in E. coli based on published measurements of mutants shows that new function can evolve with neutral and harmful mutations playing an almost negligible role (Poelwijk et al. 2006).

  2. There is a great deal of evidence showing that novel genes with novel functions can and do evolve. Even an arbitrary genetic sequence can evolve to acquire functionality (Hayashi et al. 2003). Directed evolution in vitro is a powerful and increasingly popular method of producing new genes and useful gene products (Joyce 2004; Schmidt-Dannert 2001; Tao and Cornish 2002). Directed evolution can work even starting from random sequences. Evolution of novel sequences cannot be very improbable if it happens so easily and so often.

  3. The analogy to language is flawed. Proteins are far more flexible. They can differ greatly in their sequence similarity, even seventy to eighty percent or more, and still have the same function.

  4. Denton (1998, 276) wrote, "One of the most surprising discoveries which has arisen from DNA sequencing has been the remarkable finding that the genomes of all organisms are clustered very close together in a tiny region of DNA sequence space forming a tree of related sequences that can all be interconverted via a series of tiny incremental natural steps." Meyer cites an older work of Denton (1986) without alerting readers to Denton's changed view. Denton now criticizes intelligent design advocates for ignoring the overwhelming evidence (Denton 1999).

Links:

Gishlick, Alan, Nick Matzke, and Wesley R. Elsberry, 2004. Meyer's hopeless monster. http://www.pandasthumb.org/pt-archives/000430.html

References:

  1. Denton, M. J., 1986. Evolution: A Theory in Crisis. Adler & Adler, Bethesda, Maryland.
  2. Denton, M. J., 1998. Natures Destiny: How the Laws of Biology Reveal Purpose in the Universe. Free Press.
  3. Denton, M. J., 1999. The Intelligent Design movement: Comments on Special Creationism. In: Darwinism Defeated? The Johnson-Lamoureux Debate on Biological Origins. Regent College Publishing, pp. 141-153.
  4. Hayashi, Y., H. Sakata, Y. Makino, I. Urabe, and T. Yomo, 2003. Can an arbitrary sequence evolve towards acquiring a biological function? Journal of Molecular Evolution 56: 162-168.
  5. Joyce, G. F., 2004. Directed evolution of nucleic acid enzymes. Annual Review of Biochemistry 73: 791-836.
  6. Keefe, A. D. and J. W. Szostak, 2001. Functional proteins from a random-sequence library. Nature 410: 715-718.
  7. Poelwijk, Frank J., Daniel J. Kiviet and Sander J. Tans. 2006. Evolutionary potential of a duplicated repressor-operator pair: Simulating pathways using mutation data. PLoS Computational Biology 2(5): e58. http://compbiol.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pcbi.0020058
  8. Schmidt-Dannert, Claudia, 2001. Directed evolution of single proteins, metabolic pathways, and viruses. Biochemistry 40: 13125-13136.
  9. Tao, Haiyan and Virginia W. Cornish, 2002. Milestones in directed enzyme evolution. Current Opinion in Chemical Biology 6: 858-864.
  10. Yockey, H. P., 1992. Information Theory and Molecular Biology. Cambridge: Cambridge University Press.
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created 2004-9-22, modified 2006-5-30