comparison of the genomes (the DNA sequences) of different organisms directly with each other

By Steven Hussey

Perhaps the most breathtaking scientific revelation is that of our origins: the dawn of the universe 13.7 billion years ago, the first single-celled organisms 3.5 billion years ago, and the kaleidoscope of multicellular life (and their demise) over the last 550 million years. Darwin’s On the Origin of Species has inconvenienced religious fundamentalists since 1859, but his central theory of evolution has been validated by rigorous experimentation for 15 decades. Today, we can compare the genomes (the DNA sequences) of different organisms directly with each other, revealing the precise genetic changes in their separate evolutionary journeys since their common ancestor. Evolution predicts that the earth is billions of years old. Add radiometric dating and plate tectonics theory to the equation and you have a near certainty that the earth is almost a million-fold older than 6 000 years: several stand-alone sciences conform to a beautifully parsimonious consensus.

But not everyone believes that. For the 40% of denialists in the US, no starker contrast could exist: their world was recently created, and all biology engineered by an omnipotent God. Their understanding of “evilution” is that of a masked religion devoid of evidence and the greatest hoax ever conceived. Yet we have witnessed evolution in action, even the so-called “macroevolution” denounced by the Kent Hovinds of creationism [1,2,3].

Devout young-earthers, take note: it is not this article’s point to undeservingly debate evolution and its pseudoscientific antithesis, creationism. I cannot précis 150 years of research supporting evolution, because scientific theories aren’t “proven” like a maths equation: their “proof” is the ability to survive interrogation by critical experimentation. Evolutionary theory as scientific fact is hardly disputed in academia at all. Yet, the intelligent design-promoting Discovery Institute demands that we teach the controversy! I’m afraid the only “controversy” is the recalcitrance of certain religious adherents, who will believe in talking donkeys (Num. 22:30) before evolution. There really is no controversy among biologists; they almost universally accept evolution. The latrine of saliently ill-informed, simplistic, straw man-breeding quackery about evolution in the blogosphere — the likes of David J. Smith perpetuating the misconception that evolution “just happened by sheer luck” — is as useful as a jet ski in the Sahara. Evolution is certainly not random, because natural selection is a directional, non-random force. For guidance, consult Richard Dawkins’ Climbing Mount Improbable.

But what if evolution is incorrect, hypothetically? What if God created the world and its species a mere six millennia ago? What if it simply appeared as if species evolved?

A comparison of the human and chimpanzee genomes reveals not only a staggering (>96%) similarity, but our genes are lucidly arranged in the same manner. This is a rule across all sequenced genomes: closely related species have genes with similar sequences, generally in the same order, whilst similarity and gene concordance decompose with decreasing relatedness. There is no grand function tying genes to a strict order or orientation. Rather, genes follow a pattern between related species for one reason: because they evolved from a common ancestor. Their behaviour is fickle and frivolous: genes invert themselves for the hell of it, chromosomes fuse together, and genes get duplicated or deleted altogether. Genetic commonalities between related species even include the marks of viruses that infected their common ancestors; eroded but evidential DNA signatures in the same location in their genomes. Such is the volatile, experimental nature of genetic drift and the evolutionary process, not the logical blueprint expected from a divine designer.

Explaining why the God of young earth creationism would make it look as if there was evolution is not trivial. Consider that chromosome 2 in humans appears as a perfect fusion of two chromosomes that are separated in the great apes. It takes a modest IQ to deduce that these chromosomes fused in the human lineage since our divergence from a common ancestor — the fusion site even contains the tell-tale chimp-like sequences found in the extremities of the separate ape chromosomes, proving that it is a head-to-head fusion [4,5]. Recently, a draft genome sequence of Neanderthals was obtained from bone material [6]. Their genome is even more similar to us than ours is to chimps, and non-African humans carry 1-4% Neanderthal DNA. Another genome from a not-quite-Homo sapiens, not-quite-Neanderthal hominid from southern Siberia showed a ~5% contribution from living Melanesians [7]. Why would the God of a young earth create several human-like species, each with a similar DNA sequence, but interwoven with the odd thread of shared DNA?

All organisms share the same genetic code or “language” — a creator could easily have eviscerated evolutionary theory by assigning different codes to related species. But he did not. No creator with integrity would deliberately fabricate a fossil record that proves a temporally logical evolutionary progression, if it were not actually the case. What kind of God would make it appear as if continental plates slotted together once upon a time, if they do not? What God would even implant in their rocks the precise ratio of radioactive isotopes indicative to geologists of ages amounting to millions, not merely thousands, of years? Surely not one concerned with the salvation of souls.

In countless churches and faith schools in our country, American creationist propaganda is perverting the minds of gullible youths. This, while only 57% of South Africans believe in evolution and 73% have never heard of Darwin [8]. Ironically, were evolution ever falsified, creationism would be an exceptionally weaker explanation of the available evidence. But besides that, creationism viewed against the data we have implies an unsettling reality: in allegedly creating all living things in their present form a few millennia ago, its God left behind a sinister trail of evidence from which the world’s cleverest minds conclude that species evolved over billions of years.

The God of creationism is devilishly deceptive. Or perhaps “he” simply works in mysterious ways. Either way, he is a most disagreeable deity.

Steven is a 2010 Mandela Rhodes Scholar completing an MSc in biotechnology at the University of Pretoria. e

References

[1] Observed instances of macroevolution

[2] Weinburg, JR, Starczak, VR, Jörg, D. (1992) Evolution 46(4):1214-1220.

[3] Ensatina eschscholtzi speciation in progress

[4] Ijdo, JW, et al. (1991) Proc. Nat. Acad. Sci. USA 88:9051-9055. See also Daniel J. Fairbanks’ Relics of Eden.

[5] Avarello, R, Pedicini, A, Caiulo A, et al. (1992) Human Genetics 89(2): 247-249.

[6] Green, RE, Krause, J, Briggs, AW, et al. (2010) Science 328(5979):710-722.

[7] Reich, D, Green, ER, Kircher, M, et al. (2010) Nature 468:1053–1060.

[8] www.britishcouncil.org/darwinnow-survey-global.pdf

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