Creationists miss the big picture

May 9th, 2006 The Lone Beagle Posted in Commentary |

EVOLUTION IS the variation of allele frequencies in a population as a result of differential replicative success. What this means is that both micro-evolution and macro-evolution are, to a greater extent, simply different degrees of the same thing. Micro-evolution is a term used by science to describe accumulated changes within a population, macro-evolution is a term used to describe accumulated micro-evolutionary changes that when viewed at a distance represent related organisms that we have categorized as belonging to different higher than species taxa.

The reason we know those species are related, even though they show morphologies we catagorize as belonging to different taxa - Genera, Family, Order… - is because of multiple lines of evidence.

Creationists and IDists tend to fixate on one line of evidence that may, when taken in isolation, appear to be interpretable numerous ways but when viewed in conjunction with all the other lines of evidence can be interpreted in only one way. Many of the ‘facts’ (data points) that underpin the interpretation science gives to common descent need to be considered in the light of all other ‘facts’.

In the case of common descent, where many outside mainstream science contend that the ‘facts’ can be interpreted as ‘common creation’, much is made of the ’sudden appearance’ of morphologically complete (eg. no half limbs) fossils and the human methodology of code or plan re-use in engineering projects.

What is ignored in all of this is that fossils do show features that change in function in a step-wise manner. There are lines of fossils that when considered in the context of the fossilized ecology accompanying the organisms, the chronological order of the morphological changes, as well as the obvious order to the morphological changes leads us to conclude that that line of fossils represents a branch of common descent. Two such lines are the Arteriodactyl to Cetacean branch and the Reptile to Mammal branch.

If we view this is isolation, other interpretations than evolution may be made, however if we consider these lines in light of what we know of DNA, how it changes and how it is preserved, the other interpretations fall by the way side. The analysis of DNA is probably the most important indicator of common descent we have but even it, in isolation, is open to other interpretations to a minor degree.

However if you view the structure of the Genome in light of the fossil record the other interpretations again fall by the wayside.

Many of the claims of DNA code re-use are based on a faulty understanding of the genome. There are areas of the genome that show evidence of ‘errors’ where portions of the sequence have been turned off, reversed, moved, had start/stop codons changed or even been infiltrated by viruses. Much as we can determine which craters on the Moon are more recent than others because of their overlap, (relative dating of geological strata is done this way as well) we can determine the relative timing of these ‘errors’. If we find that two or more extant species share an ‘error’ that other closely related species do not share we can conclude that those few species diverged from a common species. This shows up commonly with retro-viral insertions. The great apes, including humans, show a number of shared errors including viral insertions and genes that have been ‘turned off’. An example of this is the complex that regulates vitamin ‘C’ production in humans.

With these DNA sequence ‘errors’ in mind, it becomes pretty difficult to pass off genome similarities as just ‘common creation’ unless, for example, the creator liked the chimp genome so much he/she/it reused it to create humans, errors and all.

A word to creationists: Look at all the evidence and its interdependence rather than just looking at isolated data points (which become creationist talking points) before making judgement calls about the veracity of the SToE.