Claim CB121:

J. B. S. Haldane calculated that new genes become fixed only after 300 generations due to the cost of natural selection (Haldane 1957). Since humans and apes differ in 4.8 × 107 genes, there has not been enough time for difference to accumulate. Only 1,667 nucleotide substitutions in genes could have occurred if their divergence was ten million years ago.

Source:

ReMine, Walter J., 1993. The Biotic Message, St. Paul Science, Inc.

Response:

  1. Haldane's "cost of natural selection" stemmed from an invalid simplifying assumption in his calculations. He divided by a fitness constant in a way that invalidated his assumption of constant population size, and his cost of selection is an artifact of the changed population size. He also assumed that two mutations would take twice as long to reach fixation as one, but because of sexual recombination, the two can be selected simultaneously and both reach fixation sooner. With corrected calculations, the cost disappears (Wallace 1991; Williams n.d.).

    Haldane's paper was published in 1957, and Haldane himself said, "I am quite aware that my conclusions will probably need drastic revision" (Haldane 1957, 523). It is irresponsible not to consider the revision that has occurred in the forty years since his paper was published.

  2. ReMine (1993), who promotes the claim, makes several invalid assumptions. His model is contradicted by the following:
    • The vast majority of differences would probably be due to genetic drift, not selection.
    • Many genes would have been linked with genes that are selected and thus would have hitchhiked with them to fixation.
    • Many mutations, such as those due to unequal crossing over, affect more than one codon.
    • Human and ape genes both would be diverging from the common ancestor, doubling the difference.
    • ReMine's computer simulation supposedly showing the negative influence of Haldane's dilemma assumed a population size of only six (Musgrave 1999).

Links:

Williams, Robert, n.d. Haldane's dilemma. http://www.gate.net/~rwms/haldane1.html

References:

  1. Haldane, J. B. S., 1957. The cost of natural selection. Journal of Genetics 55: 511-524.
  2. Musgrave, Ian, 1999. Weasels, ReMine, and Haldane's dilemma. http://www.talkorigins.org/origins/postmonth/sep99.html
  3. ReMine, Walter J., 1993. The Biotic Message, St. Paul Science, Inc.
  4. Wallace, Bruce, 1991. Fifty Years of Genetic Load - An Odyssey. Cornell University Press. See particularly Chapters 5, 6, 8, and 9.
  5. Williams. (See above)
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created 2001-2-17, modified 2006-6-8