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draypresct t1_j5kqdqk wrote

Reply to comment by Robot_Graffiti in Average age at conception for men versus women over past 250,000 years by Lazylion2

>It's not based on church records, it's based on statistical modelling of a database of 45 million mutations in modern people's DNA to estimate ancient mutation rates.

They didn't use any data from the past (church records, DNA samples from remains, ?) when constructing their statistical models? If not, then how did they get different age ranges during different eras?

Sorry - I can't seem to open the link in the article to the original study.

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Robot_Graffiti t1_j5kvoef wrote

Yeah the link is broken, I had to google it.

The age estimates are based on having found a correlation between parental age and different types of mutation. The different "letters" of DNA are chemically different and the various kinds of single-letter swap mutations happen at different rates. They found by looking at present-day babies that babies with old mothers tend, on average, to have different kinds of new mutations to babies with old fathers. They then extrapolated this idea to the database of historical mutations.

How many thousands of years ago each mutation happened was estimated by a different team in a previous paper, also using statistical methods. I don't know the details of that part but I'm guessing if a gene variant is super common and widespread, it's probably old.

This all produces estimated averages for each era - they know they can't actually put an exact age and date on any one mutation, but they don't have to to get a rough average over thousands of mutations for each millennium.

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