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:
- 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).
- 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.
- 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.
- 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:
- Denton, M. J., 1986. Evolution: A Theory in Crisis. Adler & Adler,
Bethesda, Maryland.
- Denton, M. J., 1998. Nature’s Destiny: How the Laws of Biology Reveal
Purpose in the Universe. Free Press.
- 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.
- 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.
- Joyce, G. F., 2004. Directed evolution of nucleic acid enzymes.
Annual Review of Biochemistry 73: 791-836.
- Keefe, A. D. and J. W. Szostak, 2001. Functional proteins from a
random-sequence library. Nature 410: 715-718.
- 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
- Schmidt-Dannert, Claudia, 2001. Directed evolution of single proteins,
metabolic pathways, and viruses. Biochemistry 40: 13125-13136.
- Tao, Haiyan and Virginia W. Cornish, 2002. Milestones in directed
enzyme evolution. Current Opinion in Chemical Biology 6: 858-864.
- Yockey, H. P., 1992. Information Theory and Molecular Biology.
Cambridge: Cambridge University Press.
created 2004-9-22, modified 2006-5-30