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The Human Mutation Rate and Its Implications


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.

The researchers cultured cells taken from the two men, and using next-generation sequencing technologies found 23 candidate mutations. Then they validated twelve of these mutations using traditional sequencing techniques. Eight of these mutations, however, had arisen in their cell-culturing process, which left just four genuine, heritable mutations. Extrapolating that result to the whole genome gives a mutation rate of around one in 30 million base pairs.

Go To Nature for the Rest of the Article

What are the implications? I’m short on time so I’d suggest reading this exchange between myself and Joseph from last year:

Questioning the Tree of Life: International Workshop Series Comment #52 and On

The BBC picked up on this story: http://news.bbc.co.uk/2/hi/science/nature/8227442.stm I thought it funny they talk of STOPPING these mutations in order prevent diseases, degeneration, etc. What, and stop progressive evolution? Patrick
#7, I agree. I'm just pointing that in both cases we take into account the same phenomena - the changes that remain. So actual rate is undoubtedly higher. My point is just to remind that currently known rate of persistent mutations seems to be too low to satisfy human and chimp common ancestry theory. tremor
#5, I think his point is that any extremely deleterious mutations are not accounted for since obviously they would have caused death and thus they would have not been accounted for in these observations. Still, the available data is best as a baseline since it'd be difficult to impossible to estimate what occurred over those 13 generations that partially predated modern science. Patrick
That should be 150 mutations per generation. Sorry. Now back to my beer. mad doc
@Patrick #3 But when you calculate supposed rate of changes you also take only mutations that remained. tremor
It looks like Dr Sanford is correct. At 150 mutations per year this agrees with Kondrashov: HUMAN MUTATION 21:12-27 (2002) The Y chromosome is going to peg out and then thats it. (Unless evil feminist genetic engineers find a work-around) Right now I'm going to have an ice-cold beer and watch a movie. mad doc
Received another email that made a good point:
The mutation rate they measured is the mutations that actually remain after 13 generations. Their measurement omits all the mutations that were eliminated during that time. It means the actual mutation rate must be far higher than what they measured. This easily re-confirms the figures our Dr. John Sanford used in his genetic entropy thesis.
I received this email that reflects my thoughts on the subject:
That is a pretty small sampling. I would be surprised if it is a constant all over the world. Mutagenic factors may vary widely from place to place. It will be nice to get a larger sampling over time.
In addition, that does not take into account the potential rate of foresighted mechanisms. But they were focused on getting observed measurements--not just estimates as before--of undirected processes (presuming the data is the result of only such). Patrick
In comments linked at the end of article there are some calculations. Your worst case (for evolution) scenario gives: 960,000,000 (70%) / 4,100,000 = 234.15 bases/year. For more optimistic case (20m years, 85% similiarity) you got: 480,000,000 / 20,000,000 = 24 bases/year. The most optimistic rate from this Chinese research is: 200/18 = 11.11 bases/per year. Close enough not to be totally improbable, but still "off target". Of course too many unknowns to draw any serious conclusion (including dating itself as there's no reliable method to date anything several million years old). tremor

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