Miyata (1989): Evolutionary relationship of archaebacteria, eubacteria, and eukaryotes inferred from phylogenetic trees of duplicated genes, Proc. Hashimoto (2005): Root of the eukaryote tree as inferred from combined maximum likelihood analyses of multiple molecular sequence data. (The spiraling double strands of DNA are made of pairs of molecules known as bases.) Each person inherits, on average, about 70 new mutations from his or her parents.
The researchers also discovered that male chimpanzees potentially contribute three more mutations to their offspring with each year of age.
One explanation for why male chimps pass on more mutations than male humans may have to do with differences in mating behavior.
Male chimps have evolved to produce many more sperm than humans, possessing testes more than three times the relative size of human testes.
The researchers found the overall chimpanzee mutation rate was mostly the same as the human one.
"Our results indicate that human and chimp ancestors' genomes would diverge by about 0.1 percent every million years, so when we see divergence of 1.2 percent, we infer that it must have been about 12 million years — 13 million years is our actual estimate," Mc Vean told Live Science.
[Unraveling the Human Genome: 6 Molecular Milestones] The number of genetic differences between two species reveals how closely related the species are.