The myth of 1%
Human and chimp DNA are very different
We still commonly see statements that human and chimp DNA are ‘almost identical’, with only 1% difference claimed. For example, in a 2012 report on the sequencing of the other chimpanzee species, the bonobo:
“Ever since researchers sequenced the chimp genome in 2005, they have known that humans share about 99% of our DNA with chimpanzees, making them our closest living relatives.”1
And this was not from some disreputable source, but from the publishers of Science, published by the American Association for the Advancement of Science. Science is considered one of the top two science journals in the world (the other is Nature from the UK).
The original 1% claim goes back to 1975.2 This was a long time before a direct comparison of the individual ‘letters’ (base pairs) of human and chimp DNA was possible—the first draft of the human DNA was not published until 2001 and for the chimp it was 2005. The 1975 figure came from crude comparisons of very limited stretches of human and chimp DNA that had been pre-selected for similarity. The chimp and human DNA strands were then checked for how much they stuck to each other—a method called DNA hybridization.
Would a 1% difference be ‘almost identical’?
The human genome has about 3,000 million ‘letters’. If the 1% figure were correct, this would amount to 30 million letters difference, which would take 10 Bible-sized books to print. This is 50 times as much DNA as the simplest bacterium.3 This is actually a huge difference that far exceeds the ability of even the most optimistic evolutionary scenarios to create, even given the claimed millions of years.4
What is the real difference?
The publication of the human and chimp DNA sequences made possible a comparison. However, even this is problematic because the chimp genome was not built from scratch. Small pieces of the chimp DNA were first sequenced; that is, the order of the chemical letters was determined using chemical procedures in laboratories. These small strings of ‘letters’ were then aligned with the human genome in the places the evolutionists thought they should go (using computers to compare and place the segments). Then the human genome was removed, leaving a pseudo-chimp genome that assumed common ancestry (evolution), creating a mongrel sequence that is not real. The assumption of evolution in constructing the chimp genome in this way would make it look more like the human genome than it really is. But even with this evolutionary bias, the actual differences are much bigger than 1%.
In 2007 Science published an article on the similarity of human and chimp DNA titled, “Relative differences: the myth of 1%”.2 Author Jon Cohen queried the continued use of the 1% figure, citing comparisons following the publication of the draft chimp DNA sequence of around 5% difference. And yet the 1% myth is perpetuated in 2012 in the same journal.
Illustrating how wrong this is, in 2012 Drs Jeffrey Tomkins and Jerry Bergman reviewed the published studies comparing human and chimp DNA.5 When all the DNA is taken into account and not just pre-selected parts, they found,
“it is safe to conclude that human-chimp genome similarity is not more than ~87% identical, and possibly not higher than 81%.”
In other words, the differences are huge, possibly greater than 19%. Indeed, Dr Tomkins made his own thorough comparison and found the difference to be ~30%.6 Also, the Y-chromosomes, found only in males, are radically different, contrary to evolutionists’ expectations.7
Comparing two complex genomes is quite difficult. Assumptions have to be made about the importance of various parts of the DNA and the significance of different types of differences. For example, what do you do with human genes that are absent from chimps and vice versa? The tendency has been to ignore them and only compare the similar genes.
Many comparisons have involved only the protein-coding genes (only 1.2% of the DNA, and many protein-coding genes that are shared are indeed quite similar8), with the assumption that the rest of the DNA is ‘not important’ or even ‘junk’. However, this view is no longer tenable; almost all the DNA probably has a function, again contrary to evolutionists’ expectations.9 But even if ‘junk’ DNA were non-functional, the differences here are much, much greater than in the protein-coding regions and must be included when assessing differences. We are not 99% identical; nothing like it.
What would any percentage similarity prove?
Neither evolutionists nor creationists made, or could make, predictions about the percent similarity before it was calculated. In other words, whether it was 99%, 95%, 70%, or whatever, evolutionists would still claim common ancestry and we creationists would see common design. In understanding the implications of these data, we are not dealing with hard science that can be shown by experiments; everyone is deriving a meaning based on a personal worldview.
However, the larger the difference between apes and humans, the bigger the problem in trying to explain it within the evolutionary timeframe, so evolutionists have good reason to try to play down the differences.
The myth persists
Comparison of whole genomes has revealed much greater differences than 1%, and yet the myth of 1% persists. Why? Why does Science perpetuate the myth in 2012? In 2007 Cohen cited geneticist Svante Pääbo, a chimp consortium member at the Max Planck Institute for Evolutionary Anthropology, Germany, as saying, “In the end, it’s a political and social and cultural thing about how we see our differences.”2
Perhaps evolutionists will not let go of the myth of 1% because it serves a political, social and cultural purpose? What would that purpose be, other than to deny the clear implication of DNA comparisons, which is that we are very different from chimps? The myth of similarity has been used to support the claim that humans have no special place in the world and even that chimps should be granted human rights.10
The large difference does not tally with evolutionary expectations but it is consistent with us being created separately from the animals. God made the first man from dust (Genesis 2:7) and the first woman from his rib (Genesis 2:22), not from any ape-like creature. And humans, unlike other creatures, were made in the image of God (Genesis 1:26, 27), a special creation. This image was not lost but marred at the Fall,11 so God made humans with a special purpose now and in eternity.
References and notes
- Gibbons, A., Bonobos join chimps as closest human relatives, Science Now,13 June 2012; news.sciencemag.org. Return to text.
- Cohen, J., Relative differences: the myth of 1%, Science 316(5833):1836, 2007; doi: 10.1126/science.316.5833.1836. Return to text.
- The parasite Mycoplasma genitalium contains 521 genes (including 482 protein encoding genes) comprising 582,970 ‘letters’; Fraser, C.M. et al., The minimal gene complement of Mycoplasma genitalium, Science 270(5235):397–403, 1995; doi:10.1126/science.270.5235.397. Return to text.
- Batten, D., Haldane’s dilemma has not been solved, J. Creation 19(1):20–21, 2005; creation.com/haldane. Return to text.
- Tomkins, J. and Bergman, J., Genomic monkey business—estimates of nearly identical human-chimp DNA similarity re-evaluated using omitted data, J. Creation 26(1):94–100, April 2012; creation.com/chimp. Return to text.
- Tomkins, J., Comprehensive analysis of chimpanzee and human chromosomes reveals average DNA similarity of 70%, Answers Research Journal 6(1):63–69, Feb. 2013; answersingenesis.org. Return to text.
- Catchpoole, D., Y chromosome shock, Creation 33(2):56, 2011; creation.com/chimp-y. Return to text.
- Many proteins are very similar across a wide range of species, so comparing only protein-coding DNA tends to artificially accentuate similarity. Histones, which are involved in chromosome structure, and osteocalcin, which is a bone protein, are almost identical across many creatures. Differences between species seem to be due more to the non-protein-coding DNA that controls when and how much of the proteins are made. See Carter, R., Splicing and dicing the human genome, 1 July 2010; creation.com/splicing. Return to text.
- Batten, D., Dazzling DNA, Creation 35(1):38, January 2013. Return to text.
- Cosner, L., Going ape about human rights: Are monkeys people, too? creation.com/goingape, 9 July 2008. Return to text.
- Cosner, L., Broken images, Creation 34(4):46–48, 2012. Return to text.