July 23, 2004 | David F. Coppedge

Evolutionists Consider Non-Darwinian Mechanisms

According to classical Darwinian evolutionary theory, variations in the germ lines produce phenotypic changes that, on rare occasions, prove beneficial to an individual, and cause an organism to outcompete its peers in the struggle for existence.  The hypothesis of Natural selection claims that the individual with a slightly beneficial variation, being more “fit,” leaves more offspring.  Darwinian changes are gradual, random and independent.  No sudden leaps (saltations) are allowed, and changes do not “conspire” toward a goal (i.e., no “orthogenesis” or straight-line evolution).  Natural selection acts on genes in the individual (individual selection).  Speciation occurs when a population becomes geographically isolated from another population (allopatric speciation) and the accumulated changes no longer permit interbreeding.  Darwinians believe this gradualistic process is sufficient to account for all the innovations in all living things since the first cell emerged on Earth: all the organs, functions and behaviors of birds, insects, fish, plants and man.  Darwin did propose an additional mechanism, sexual selection, in The Descent of Man.  Ever since On the Origin of Species by Natural Selection was printed, however, competitors have proposed other mechanisms for evolution: group selection, kin selection, sympatric speciation, various Lamarckian mechanisms (inheritance of acquired characteristics), niche construction, Gaia, and more.  The debates still go on today.  Two recent papers offer “new” non-Darwinian mechanisms that might supplement the process of natural selection.
    According to EurekAlert, scientists at the Universitat Autonoma de Barcelona have discovered a “New genetic mechanism for evolution.”  In their view, transposable elements (transposons) in the genes can generate antisense messenger RNA (mRNA) in neighboring genes that can silence or otherwise alter the expression of the genes.  “For a long time they [i.e., transposons] have been considered as a useless part of genetic material, DNA left overs,” the press release states.  “However, it is more and more clear that transposons can cause favourable changes for the adaptation and survival of the organism.”  The press release does not provide any evidence of an innovative change due to this mechanism, but they point to an observation in fruit flies that some with an antisense mRNA caused by a transposon grew larger and lived longer, presumably due to the switching off of a gene.
    The way it’s taught in school, Darwin rendered Lamarckism obsolete (even though Darwin himself shifted toward a more Lamarckian view later in life.)  But surprisingly, in Science this week,1 four biologists make the case for a Lamarckian mechanism of evolution.  Although physically acquired characteristics may not be heritable, culturally acquired characteristics can be.  You may not inherit your grandfather’s wooden leg, for instance, but you might pass on his stories to your children.  The authors claim that many animals can learn by watching, and pass on what they learn: a bird might learn a new mate attraction technique by watching another bird, or a mouse might learn that crossing the road is dangerous by watching a friend get run over.  Such cultural lessons are “public information” (PI) that is heritable, they claim, and so cultural evolution (that acts on memes; i.e., ideas, behaviors or styles that spread socially) might influence biological evolution (that acts on genes).  At least, they think, the suggestion deserves more thought:

PI is a widespread phenomenon that is emerging as a potential unifying concept in fields that involve decision-making processes in which individuals can extract information from others to assess resource quality.  The use of PI can enrich evolutionary models and can have marked effects on evolutionary predictions.  Future research should explore the extent to which evolutionary scenarios are affected by the use of PI.

They continue, “the ability of individuals to use PI unites a range of topics as diverse as foraging, predation, mate choice, habitat selection, and colony formation.”  PI may be, in fact, the major driving force in social evolution, and may imply that cultural evolution is more widespread than previously thought.  “Moreover,” they propose in conclusion, “although much work has been devoted to exploring how biological evolution affects culture, we suggest that evolutionary biologists should also consider how cultural evolution influences biological evolution.”

1Étienne Danchin, Luc-Alain Giraldeau, Thomas J. Valone, and Richard H. Wagner, “Public Information: From Nosy Neighbors to Cultural Evolution,” Science, Vol 305, Issue 5683, 487-491, 23 July 2004, [DOI: 10.1126/science.1098254].

Even though it is amusing to watch the Darwin Party argue over which mechanism they like best, it is all beside the point.  As Phillip Johnson pointed out over a decade ago in Darwin on Trial, none of these mechanisms establish the very thing that Darwin set out to explain in the first place: that unguided natural processes unaided by any intelligent design had creative power to generate eyes, ears, wings, intelligence or any other complex feature; nor did Darwin or his followers find any historical evidence that a long chain of intermediates actually ever existed.
    Physical similarity is not enough as evidence for evolution.  Even creationists like Linnaeus were intimately acquainted with similarities between organisms.  The ability to classify organisms according to similarities is insufficient to establish the claim that humans had bacteria ancestors; it might establish just as well that all organisms had a common Designer.  The two proposals above fail again on both counts.  Neither demonstrates any creative power, and neither points to any plausible chain of intermediates.  To expect transposons are somehow creative and can generate complexity is to endow them with angelic powers.  To expect that public information in a herd of theropods could help them sprout wings seems ridiculous.  Where is the evidence any creative innovation was produced by these or any other proposed mechanisms?  It is not only missing; the evidence we do have points in the opposite direction: (1) the Cambrian explosion shows a sudden appearance of complexity without precursors, and (2) the law of entropy demands that information (public or not) degenerates through transmission rather than improves.
    Evolutionary theory is like a smorgasbord of rotten food.  The cooks keep thinking if they add one more dish, customers will find something they like.  Instead, it has turned into a food fight.

(Visited 25 times, 1 visits today)
Categories: Uncategorized

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.