August 20, 2012 | David F. Coppedge

Evidences for Evolution Examined

Recent news stories have claimed evidence for evolution.  But has evolution been observed or assumed?

Snake transitional form:  In Nature last week, Longrich et al. claimed fossil evidence for a transitional form between lizards and snakes.  The fossil, named Coniophus, was known since 1892 from fragments, but the authors claim newly-discovered skull and vertebral parts establish its ancestral position.  The authors call it, however, a “mosaic” of features with “synapomorphies,” which, in cladistics, refers to traits shared by two taxa and their most recent common ancestor.  Their diagrams show a lizard head, a snake head and the Coniophus reconstructed head, each looking distinctive.  If this is a transitional form, furthermore, it is rare: “Snakes are the most diverse group of lizards, but their origins and early evolution remain poorly understood owing to a lack of transitional forms,” they said.  Owing primarily to its small size and non-motile jaw, they believe, “Coniophis therefore represents a transitional snake, combining a snake-like body and a lizard-like head.” (Longrich et al., “A transitional snake from the Late Cretaceous period of North America,” Nature 488, 09 August 2012, pp. 205–208, doi:10.1038/nature11227).

There has been a long-standing debate between evolutionists whether snakes evolved in the ocean or on land.  The authors feel Coniophus suggests a land origin: “its small size and reduced neural spines indicate fossorial habits, suggesting that snakes evolved from burrowing lizards.”  It would seem, however, that one oddball does not justify the assumed evolutionary story that follows: “Subsequent to the evolution of a serpentine body and carnivory, snakes evolved a highly specialized, kinetic skull, which was followed by a major adaptive radiation in the Early Cretaceous period. This pattern suggests that the kinetic skull was a key innovation that permitted the diversification of snakes.”  Coniophus, however, lacked the kinetic skull.  The Editors’ Summary is tentative, saying that the study “has come up with some facts that favour a land-based genesis for snakes,” and “suggests that early snakes were burrowers that achieved their elongate form before evolving the characteristic highly mobile skull of modern snakes.”  There are, however, legless lizards; it is not clear why the authors did not comment on that possible interpretation of this fossil.

Moth pheromones:  Male moths have a remarkable ability to detect female sex pheromones at long distances, even though the molecules weigh billionths of a gram.  In a recent open-access PNAS paper, evolutionists admitted that “little is known about the molecular mechanisms that underlie the evolution of new sex pheromone blends between closely related species.”  They succeeded in mutating a male moth’s antenna to increase its long-range sensitivity to a mutated female’s hormone.   The mutation they studied appeared to increase the sensitivity to a particular pheromone molecule in the female’s blend of exuded pheromones while narrowing its sensitivity to the blend, “altering the tuning profile of this broadly responsive neuron.”  Tuning an existing system says nothing about the origin of the system.  A summary on Science Daily did not clarify if this was alleged to be an example of Neo-Darwinian evolution.

Changes such as this could represent designed adaptability, therefore, analogous to the adaptive immune system, rather than neo-Darwinian processes at work.  The authors said as much: “variability in the breadth of male response required to track new pheromones exists in the population.”  The authors noted that researchers in this area are not sure what evolutionary processes are at work in moth pheromone tracking.  It could be stabilizing selection, asymmetric tracking, reinforcement, communication interference, or some combination of the above.   All in all, in spite of their minuscule finding of one mutation that appeared to increase sensitivity amplitude while narrowing sensitivity breadth, they confessed, “The molecular mechanisms that enable male moths to respond to new female pheromones during the evolution of the sexual communication channel remains a long-standing question.”  (Leary et al., “Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species,” PNAS, August 13, 2012, doi: 10.1073/pnas.1204661109).

FirefliesNew Scientist presented an article about the evolution of cold light (bioluminescence), claiming that marine animals invented it in the Devonian (at least 400 million Darwin years ago), but land insects invented it far more recently – in the Cretaceous, no more than 65 million years ago.  This “unexpected” “discrepancy” left Slavic paleobiologist Peter Vršanský scrambling for explanations.  Maybe “luminescent species appeared on land only when night life began to diversify,” the article claimed; or, perhaps, “terrestrial species have only recently cracked the problem of disposing of the toxic by-products of bioluminescence.”  If evolution cannot solve a simple problem like that, however, it casts doubt on the ability of the “tinkerer” to produce giraffes and eagles in far less time.  The explanation further suggests the absurdity that land insects were trying to evolve bioluminescence, but couldn’t because of toxic waste.

Plant sex:  An article on PhysOrg claims, “Researchers solve plant sex cell mystery,” adding, “plant sex cells have stubbornly guarded the secret of their origin” till researchers at Stanford figured out the secret: low oxygen levels.  That hypothesis, however, if a natural law, would bring sex cells out of any somatic cell, or out of rocks, for that matter.  According to the report, “the researchers demonstrated that low oxygen levels deep inside the developing flowers are all that is needed to trigger the formation of sex cells.”  This finding, however, says nothing about the origin of sex cells in the first place – only what triggers their development.  As such, the article has nothing to say about evolution.  It might just as well be about epigenetic regulation of existing design.

Human heightLive Science claims in bold headlines, “Evolutionary Battle of the Sexes Drives Human Height.”  Careful reading, though, shows a convoluted suggestion that cannot be tested.  Reporter Stephanie Pappas began, “For women looking to pass on their genes, it pays to be short. For men, tall is the ideal.”  No evidence was offered for why this should be so, instead of the opposite.  But it was the basis for a claim, “The result? An evolutionary tug-of-war in which neither gender reaches their perfect height.”  Gert Stulp, the expert in the Netherlands who stated this hypothesis, spoke of “evolutionary pressure” that kept human heights varying incessantly in an “evolutionary back-and-forth” with no direction or conclusion.  From this inconclusive explanation, Stulp leapt into a whole mess of other possible non-converging evolutionary tug-of-wars: hip width, facial masculinity, and mate choice, for instance.  These appear to be post-hoc rationalizations for evolutionary theory, though, instead of evidencesUndoubtedly this kind of thinking could rationalize any observation into an evolutionary explanation.  It also ignores the fact that men and women might make their mate choices by intelligent design.  Consequently, it seems a stretch for Stulp to conclude, “I think it is important to recognize that evolutionary processes occur in contemporary human populations.  Evolution did not stop at the industrial revolution.

Using evolution to fight cancer:  A scientific theory is bolstered if it can make predictions that lead to practical applications.  This might be the case with a Science Daily story with the promising headline, “Using Millions of Years of Cell Evolution in Fight Against Cancer.”  Below the headline, though, a reader will look in vain for anything beyond a mere assumption of evolution and millions of years.  John McDonald (Georgia Institute of Technology) inserted micro-RNAs (miRNA) into cells by design, to study their downstream effects on gene regulation.  He also witnessed design: “McDonald noticed that most of what changed downstream was functionally coordinated.”  He then wrongly linked evolution to a coordinated purpose: “miRNAs have evolved for millions of years in order to coordinately regulate hundreds to thousands of genes together on the cellular level.”  The story, therefore, has nothing to do with aimless, purposeless processes of neo-Darwinism, but everything to do with intelligent design:  “If we can understand which miRNAs affect which suites of genes and their coordinated functions, it could allow clinicians to attack cancer cells on a systems level, rather than going after genes individually.”

We always like to give the Darwin Team the best possible racing conditions before watching their contestants stumble and fall on the starting line.

 

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Comments

  • Buho says:

    Re: Human height, also: if males are trying to be taller and females are trying to be shorter, what of the anglerfish http://en.wikipedia.org/wiki/Triplewart_seadevil and the garden spider http://en.wikipedia.org/wiki/Argiope_appensa where the males are 1/10 the size of the females?

  • rockyway says:

    1. Re human height;
    – the idea of a perfect height would seem to make no sense, and even if it did, how would the author/s determine what this imagined height would be? We might call this the height of silliness.

    2. “Evolution did not stop at the industrial revolution.”
    – This remark confuses evolution and variation. (They themselves admit that this ‘evolution’ isn’t going anywhere.)
    The word evolution is now used in such a sloppy and careless fashion that it has come to have no meaning at all. We should demand more precision from scientists than this.

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