Refusal vs Refutation

Refusal to believe theories that logically follow from evidence does not constitute refutation. This point is missed by creationists when they deny the evidence that led to evolutionary theories, or when they fail to understand that there is not one single theory that seeks to explain the fact of biological evolution, or when they mistake acknowledgement of incomplete explanation for a complete failure of explanation.

There are undoubtedly numerous explanations for the cognitive errors and illogic of collective creationist positions. Most obvious is the impact of poor science education in those areas of the U.S. in which fundamentalism is deeply entrenched.

Individuals who have been raised with insistent belief in special creation experience dissonance when faced with scientific facts, so they are likely to close their minds to those facts. The handfull of scientists who make their living through the advocation of anti-science promotion of ID theory cannot be accused of lack of science education per se, so their motivation in promoting creationism must stem from cognitive bias founded in inculcated religious convictions.

The problem of dissonance is, of course, compounded for most creationists by anti-science policies adopted by those in charge of education in Bible Belt states. Such policies lower the standards of science education to deplorable levels for a supposedly advanced nation [NSTA, NSES, 8th grade, PISA]. For example, US students ranked between 20th and 27th of 4o nations in a 2003 comparison of scores on science testing (Source: Organization for Economic Cooperation and Development, OECD PISA (Program for Student Assessment) 2003 database.)

The low level of science education of many creationist debaters is compounded by their repetition of information found in books and on websites with pro-creationist/anti-science bias. With little apparent comprehension of the scientific principles under discussion, and without apparent awareness that the information that they parrot is incomplete, biased, or inaccurate, creationist debaters are ill-equipped to refute the logic of science. They remain blissfully, if irritatingly ignorant of the theories that they attack, and most show no signs of willingness to acquaint themselves with those facts or to subject their own beliefs to scrutiny.

One glaring example of creationist ignorance of evolutionary science is illustrated by an insistence upon treating all evolutionary theory as beginning and ending with Darwinism coupled with an apparent lack of awareness of any form of mutation other than the point-mutation. They alone know whether they adopt this position of anti-science ignorance out of lack of acquaintance with scientific principles and/or with insistence upon the safety of attacking straw men. However, considering the anti-science education position espoused by the ID platform, coupled with poor standards of science education and evident antipathy to science and to intellectualism, it seems probable that most of the cognitive errors and illogic displayed by most creationist debaters stem from obdurate ignorance of science (at the very least).

Another example of ignorance in creationist debaters relates to their failure to distinguish between abiogenesis – the theory that life arose in primordial chemicals – and biological evolution, those events that altered the frequency of alleles down through successive generations of live organisms. Although biological evolution acted upon the products of biopoiesis (abiogenesis), the two are no more the same than rusting is equivalent to automobile manufacture.

Biological evolution

Scientific theories of evolution seek to explain the mechanisms of the observable fact of biological evolution. Yes, organisms have indeed evolved over time – most former species are now extinct, many species remain much as they are in the fossil record, and new species continue to evolve.

Historically, scientists observing biological evolution first sought to explain observed morphological (body shape) changes over time – the phenotypic evidence of changes in body structure found in the fossil record. Bacteria were the first life-forms on the planet, and ruled until the advent of nucleated cells with membranous organelles, such as those of which we are constructed. The earliest known fossilized evidence of early life forms are found in stromatolites – large reef structures created by communities of Cyanobacteria. Mistakenly called ‘blue-green algae’, the Cyanobacteria are believed to have “invented” oxygenic photosynthesis over 1 billion years ago. As oxygen levels rose, organisms were forced into endosymbiotic unions as – to them – toxic levels of oxygen threatened their continued existence. Anaerobic bacteria, which are killed by oxygen, persist to this day in environments with very low levels of oxygen.

Since the advent of modern molecular genetics, biological evolution has come to be understood as a change in genotype – a genetic alteration in the intergenerational frequency of alleles in populations. That is, an alteration in the frequency of alternative forms of genes between generations. By this definition, the human species is still evolving.

Biologist Ersnt Mayr suggested that a biological species be defined by its inability to produce fertile offspring when mated with another species. Mules are an example of such a mating – between a horse and a donkey. Mules do rarely produce offspring, but the gene-based, phylogenetic classification of species remains more useful than taxonomies based on physical characteristics. Molecular geneticists are able to compare the genomes, the total complement of nucleic acids, of different species and to estimate the evolutionary distance between species. This is time since the compared species last shared a common ancestor.

Speciation depends upon genetic change, yet morphologic changes may reflect alterations in the regulation of genetic expression without a major alteration in genotype – body type may appear very different without considerable change in genes.

If this seems unlikely, just consider the considerable differences that selective breeding has wrought in size and configuration within one canine species. Mechanics might prevent the union of a Chihuahua with a Great Dane, but such a union could produce fertile offspring.

Similarly, the paramount importance of gene regulation almost certainly explains much of the morphological difference between humans and chimps – two species who share 98% of their DNA.

Along the same lines of modification of genetic expression, the epigenetic mechanism of alternative splicing enables a single gene to give rise to multiple versions of a protein. Proteins are much, much more variable in structure, and hence in biochemical activity, than are nucleic acids such as DNA and RNA. Formed from amino acids, proteins regulate cellular metabolism (as enzymes), regulate genetic expression (cofactors), and regulate communication between cells (ion channels, pumps, receptors). Structural proteins form the cytoskeleton that supports cells, and specialized transport proteins move materials and organelles within cells and effect muscular contraction.

There are two basic types of mechanism involved in biological evolution. First are the genetic causes of alteration of genes within the genotype of individuals. Most genetypic alterations are not the result of point mutations, which may, or may not result in abnormal proteins through alteration of a single nucleobase in the genetic code. Creationists create fallacious strawman arguments by focussing their arguments on point mutations, conveniently ignoring the other, more important mechanisms of genetic change.

Single nucleotide polymorphisms, as point mutations are correctly termed, as well as alteration of longer segments of DNA may be neutral, beneficial, or deleterious. Clearly, neutral or beneficial alterations, whatever their genetic mechanism, will persist while deleterious alterations will ultimately be eliminated if they render the organism less capable of reproductive success.

This brings us to the second type of mechanism operating in biological evolution, the statistical mechanisms that determine the fate of an altered gene. These are the mechanisms that increase or decrease frequency of an allele – an alternate gene at a particular chromosomal position –within a population. Natural selection, the Darwinian explanation for biological evolution, remains one of the mechanisms acknowledged by biologists, yet not the only recognized mechanism.