Every time human DNA is passed from one generation to the next it accumulates 100–200 new mutations, according to a DNA-sequencing analysis of the Y chromosome.
This number — the first direct measurement of the human mutation rate — is equivalent to one mutation in every 30 million base pairs, and matches previous estimates from species comparisons and rare disease screens.
The British-Chinese research team that came up with the estimate sequenced ten million base pairs on the Y chromosome from two men living in rural China who were distant relatives. These men had inherited the same ancestral male-only chromosome from a common relative who was born more than 200 years ago. Over the subsequent 13 generations, this Y chromosome was passed faithfully from father to son, albeit with rare DNA copying mistakes. Read More ›