pangloss

I posted this on the OCW forum, where ReMine had poppped in for a short time. Of course, he ignored it. I have noticed that a couple of posters on ARN have picked up on it and have presented the citations there, but they've been ignored, too.
I am in the process of writing a review of a section of ReMine's book. The shoddy scholarship oozes from every paragraph, and the arrogance makes it difficult to stomach. In the section I am reviewing, EVERY one of his positive claims is supported by:
his assertion.

And nothing else.... Amazing...

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The following papers:

J. C. Fay, G. J. Wyckoff and C.-I. Wu: Positive and Negative Selection on the Human Genome, Genetics 158, 1227-1234. 2001.

and

Sexual Recombination and the
Power of Natural Selection
William R. Rice* and Adam K. Chippindale
2001 Science 294:555-559


severely impact the various claims of creationists who insist that because of 'Haldane's dilemma', among other things, human evolution from an ape-like ancestor is impossible.

This 'conclusion' is premised primarily on personal opinions, for there is, at present, no information at all regarding the numbers of fixed beneficial mutations required to explain various adaptations and traits in extant organisms.

Nonetheless, the argument regarding the human question goes something like this:

According to an extrapolation of Haldane's 1957 paper, no more than 1667 fixed, beneficial mutations could accrue in the lineage leading to humans from an ape-like ancestor.

1667 is too few to account for this (unsupported assertion), therefore, humans must not have evolved at all.

According to the first paper mentioned, the number is off - way off. We cannot blame Haldane - he was working more than a decade before and sequence data was available to him.
This paper demonstrates that there have been approximately one beneficial allele substitution every 200 years since the split between Old and New world primates some 30 million years ago.

This amounts to 150,000 in 30 million years. The estimated split between the lineage leading to humans from that leading to chimps is around 5-6 million years ago.

We'll go with 5. That allows for some 25,000. That is 14 times what was allowed under Haldane's model.

Considering the fact that HGP analysis and others put the total gene number in the human genome at between 30 and 60,000, and if we consider that each of these genes may be influenced by at least one regulatory region, 25,000 substitutions - by anyone's standards - should be seen as more than enough to acocunt for the differences.

Of course, since it is a fact that it has not been shown that 1667 fbms is too few, I am still not convinced that it cannot be explained by the lower number.

I suppose it all rests on one's point of view, and whether or not one is willing to accommodate new discoveries into their lexicon.

From the second paper, emphases mine:

"Our results experimentally verify a counteracting advantage of recombining compared to clonal lineages: reduced accumulation of harmful mutations and increased accumulation of beneficial mutations.The magnitude of this benefit will accrue over geological timeand promote the superior persistence of recombining lineages at both the
level of species within communities (clonal versus sexual species) and genes within chromosomes (nonrecombining Y-linked versus recombining X-linked genes)."

I don't think that needs any more explanation.

Comments appreciated

theyeti

I certainly don't think that 1667 is too few. The vast majority of alleles in humans and chimps are identical, or nearly so. The major differences are probably relegated to a relatively small number of regulatory genes, like for instance those that slow our development al la neoteny.

The Rice and Chipendale paper is really cool. It's the first time I think that experimental evidence has confirmed what before was almost exclusively the theoretical work of explaining sex. There's a couple of good comentaries, one in the Science issue in which the original article appears, and one in the Dec. issue of Nature Reviews Genetics. Oh, and here's a url for the Rice lab: <a href="http://lifesci.ucsb.edu/EEMB/faculty/rice/research.html" target="_blank">http://lifesci.ucsb.edu/EEMB/faculty/rice/research.html</a>

I've never thought that Haldane's Dilema was very pertinent anyway given all the assumptions that come with it. Correct me if I'm wrong, but I thought that it assumed a relatively large and constant population size. In nature though, populations are constantly in flux, greatly increasing the rate of selection.

theyeti

Valentine Pontifex

If you get that review of ReMine's book finished, be sure to post it in the Talk.Origins newsgroup and propose it as an FAQ.

I have not read his book, but I know the core of his argument is that Haldane's dilemna eliminates the possiblity of evolution in the amount of time that it has had to deal with.

Of course the problem is that for this reasoning to be sound, the assumption of the argument must be true. If the assumptions of Haldane's dilemma are false then ReMine's arguement falls appart.

Haldane's dilemma assumes that every gene in the genome is completely independ of each other. In other words if regulatory genes exist then the assumptions Haldane are false and hense ReMine's argument fails. Regulatory genes exist.

Haldane also assumed that all natural selection is
"hard." The distinction between hard and soft selection did not even exist when he wrote his paper. Basically Haldane assumed that when natural selection occured, an additional organism
or organism died that would not have died if selection already took place: x+y deaths instead of x deaths. In reality, selection can be soft.
In other words without a new selection presure x die and with it x die with the selection presure determining who will be among the x.

So on and so forth...

CodeMason

Didn't Haldane's dillema only refer to the cost of natural selection for when a previously near neutral allele is rendered beneficial by a detrimental environmental change? Of course, due to the death of the rest of the population, this would incurr some cost, but this says nothing about new, beneficial alleles appearing and being selected for normally. So where's the dillema?

Also, taking into account soft selection (life is a struggle for survival, remember?) and punctuated equilibrium (rapid selection within small populations of the whole) even if there is some sort of cost for normal evolution, it seems to be negligable.