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Thread: No single birthplace of mankind, prominent scientists say

  1. #11
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    Quote Originally Posted by Cosmo View Post
    Thank you for that link. I found it quite interesting. Some very curious stuff in there, like....

    So the extra mutations in A00 for example don't seem to have been subject to purifying selection. That's hardly consistent with the idea that they were a non-Sapien introgression. Y-DNA is a desert for Neanderthal genes for example. Something does not add up here.

    Very possible. Documented even. Which is why it doesn't make sense to use a North Asian and Northern European from frigid climates to calculate mutation rates for Africans 200,000 years ago.

    I am still open, but so far I haven't seen anything which convinces me that that A00 is substantially older than 200K.
    Yfull's estimate is "formed 235900 ybp"
    their FAQ about their age estimation methodology links to this paper

    I think if you were to want to do a practical estimate that far back in time you'd have to estimate mutation rates using only ancient samples under the assumption that it's non linear. Samples from varying archaeological cultures dating to after the advent of settled life would have to be examined separately because settled life at least increases the likelyhood that paternal age will increase either on average or with enough frequency that it could increase the mutation rate and this phenomena is likely to be very uneven between cultures if the modern variation is anything to go by.

    Two papers, one from an institute i'm not familiar with and one from Reich's lab (he was involved in both)
    Last edited by xenus; 06-07-2019 at 12:39 AM.

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     TuaMan (06-07-2019)

  3. #12
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    Other than parental age at conception, what are some other variables that could impact mutation rates?

  4. #13
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    Population growth would be the first thing I can think of and definitely one of the biggest.

    Some plants contain mutagens. Cooking can create and/or release mutagens as well so the shift to cooking our food that
    played a big part in our early history is likely to have increased mutations. If they cause germ line mutations that can be passed on would require looking at it in more detail but I think it's highly likely that certain groups would take up certain foods or cooking methods that would cause germ cell mutations.

    I don't know if it's ever been tested or demonstrate but I'd bet that exposure to most kinds of smoke can cause mutations with enough exposure. Not to the levels of say cigarette smoke but burning fields or daily exposure to incense might do it.

    Exposure to radiation
    exposure to radon in caves and then later on when humans began mining.

    Those are the things that came to mind but i know there are others i'm missing.

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