Molecular Clocks: Michael Denton continues to be vindicated
|December 14, 2006||Posted by scordova under Intelligent Design|
…the idea of uniform rates of evolution [molecular clocks] is presented in the literature as if it were an empirical discovery. The hold of every evolutionary paradigm is so powerful that an idea [molecular clocks] which is more like a principle of medieval astrology than a serious twentieth-century scientific theory has become a reality for evolutionary biologists…the biological community seems content to offer explanations which are no more than apologetic tautologies.
Michael Denton, Evolution: A Theory in Crisis (1985)
Well this principle of “medieval astrology” used by evolutionary biologists continues to come apart.
See this article in a peer-reviewed scientific journal:
Dates from the molecular clock: how wrong can we be?
Large discrepancies have been found in dates of evolutionary events obtained using the molecular clock. Twofold differences have been reported between the dates estimated from molecular data and those from the fossil record; furthermore, different molecular methods can give dates that differ 20-fold. New software attempts to incorporate appropriate allowances for this uncertainty into the calculation of the accuracy of date estimates. Here, we propose that these innovations represent welcome progress towards obtaining reliable dates from the molecular clock, but warn that they are currently unproven, given that the causes and pattern of the discrepancies are the subject of ongoing research. This research implies that many previous studies, even some of those using recently developed methods, might have placed too much confidence in their date estimates, and their conclusions might need to be revised.
This article was motivated by the experience of a colleague who estimated the time since the separation of two taxa from the number of substitutions that had accumulated between their DNA sequences; in other words, he was using the molecular clock. On submitting the work for publication, he was startled to be advised by a referee that his estimate was wrong by a factor of ten. The argument concerned the tick rate of the molecular clock; that is, the rate of accumulation of substitutions per million years. How could the scientific community hold two such contradictory opinions simultaneously?
Our colleague’s original calculation was based on a rate estimated from inter-species comparisons, whereas the referee preferred a rate obtained from a pedigree study. Later, we address why such discrepancies exist between estimates of substitution rates. The central lesson for this article, however, is the realization that reasonable scientists working with the molecular clock can be using estimates that are so different. If neither the fast estimate nor the slow estimate were self-evidently wrong, it suggests that it is difficult to validate them using our knowledge of biogeography and the fossil record. Methods are currently being devised that deal with uncertainty about the variation in the rate and about the timing of the calibration points. Here, we consider the prospects of obtaining date estimates that take account of these issues when constructing their standard errors (or analogous measures of uncertainty): is there likely to be so much uncertainty about molecular dating that the estimates are no longer useful? We fear that, for many current studies, the answer is yes. However, it might be possible to gain extra precision using recently developed methods. The degree of improvement depends on the pattern of variation in the rate of molecular evolution and the availability of calibration points. We currently do not know enough to be confident in the prospects of these new methods, and some initial results are discouraging.
And the bad news continues. Darwinism continues to self-destruct on its own demerits.
Finally, I should add, one of Behe’s first ID-friendly peer-reviewed articles extended Denton’s claims. See: Histone deletion mutants challenge the molecular clock hypothesis.
Behe is getting some vindication as well.