Protein clock dating

While there are clearly many morphological similarities between humans and chimpanzees, for example, certain studies also have concluded that there is roughly a 98 percent commonality between the DNA of both species.There are two continuous linkage groups in humans that are carried by a single sex.

The authors proposed that amino acid differences in a protein should accumulate at, more or less, a uniform rate across different species.That is, differences between sequences would accumulate in a linear fashion.In addition, they suggested that this uniform rate of a specific protein would be approximately constant, not just over evolutionary time, but also across different lineages or taxonomic groups.That means that the two DNA versions differ by 100 million years of evolution and that their common ancestor lived 50 million years ago.Since each lineage experienced its own evolution, the two species must have descended from a common ancestor that lived at least 50 million years ago.

Leave a Reply