The results are plotted a a fraction of sequence identity. (Convert to percent by multiplying by 100.) The window is 100 kbp (100,000 bp). Human chromosome 2 is on top and chromosome 7 is below.
Notice that the substitutions are pretty much randomly scattered over every part of the two chromosomes. The data is consistent with the idea that most of the DNA in those chromosomes is junk and most of the substitutions are nearly neutral mutations fixed by random genetic drift. The differences between each pair of species is consistent with an approximate molecular clock corresponding to a constant mutation rate over million of years. The absolute levels of sequence identity (i.e. 98-99% for chimp/human) is consistent with the time of divergence from a common ancestor based on the fossil record and other criteria.
Here are my questions. Is there any other explanation that accounts for the data? Is it possible to explain the results as adaptations—substitutions that are mostly fixed by natural selection? Is it possible to explain the results according to Intelligent Design Creationism?
I'm particularly interested in hearing from the creationists. What is your explanation?
Marques-Bonet, T., Ryder, O.A., and Eichler, E.E. (2009) Sequencing Primate Genomes: What Have We Learned? Ann. Rev. Genomics Hum. Genet. 10:355-386. [doi: 10.1146/annurev.genom.9.081307.164420]