Chimp genes 83% non-human, according to The International Chimpanzee Chromosome 22 Consortium’s report in Nature, vol. 429, p382, and Nature Science Update, 27 May 2004. The consortium carried out a detailed study of one chimpanzee chromosome, number 22, and compared it with the equivalent human chromosome, number 21. (The reason for comparing chimp chromosome 22 with human chromosome 21 is that chimps have 48 chromosomes and humans have 46, so equivalent gene sequences are not on the same chromosome.) In the regions that had the same genes as humans they found 1.44 percent single-base ‘substitutions’, i.e. different DNA letters. This was in line with claims that chimps are 98.5 percent the same as humans.
However, to complicate matters, there were also 68,000 “insertions and deletions”, i.e. regions where there were extra pieces or missing pieces, when compared with the human chromosome. According to Consortium scientists, “These differences are sufficient to generate changes in most of the proteins. Indeed, 83 percent of the 231 coding sequences, including important genes for brain function, show differences at the amino acid level.” (This means proteins made from these genes would be different in structure and function.) As this chromosome makes up only one percent of the total genome, there could be thousands of genes that are significantly different from humans. The team also looked at how active the genes were, and found that 20% of the genes were very different in their pattern of activity.
Editorial Comment: The chimp genome has been much anticipated by scientific news services, but they don’t seem to be too pleased about these findings. How many mainstream news services reported it? ScienceNOW had only the following small paragraph: “Head scratcher. The DNA sequence of chimpanzee chromosome 22, reported in the 27 May issue of Nature, may overturn the common assumption that only slight genetic differences separate us from our closest primate relatives. The researchers say 83% of 231 genes on the chimp chromosome would produce different amino acid sequences than their human counterparts (on our chromosome 21).”
This is the first study that actually compares specific genes and gene activity. Therefore, it gives a truer picture of differences between the chimp and human genomes. Creation Research predicts that as more detailed chimp gene studies are done, even more differences will be found, especially when scientists understand how genes are activated and interact with one another. The basis of this prediction – only humans were made in the image of God. (Ref. Chimpanzee, chromosome, genes, prediction)