[ExI] homo sapiens as endangered species
kellycoinguy at gmail.com
Thu Jun 2 19:26:19 UTC 2011
2011/6/2 Stefano Vaj <stefano.vaj at gmail.com>:
> On 2 June 2011 18:58, Anders Sandberg <anders at aleph.se> wrote:
>> When I saw the subject of this thread I thought it was more about xrisks.
>> I have been tinkering with some minimum viable population models of H.
>> sapiens. If we are ever near extinction, it is pretty tough to maintain a
>> population - big mammals are tricky.
> I have some vague recollection of this notion, but do not remember the
> reasoning behind it.
> Why a few fertile individuals are actually not enough?
One reason a few fertile individuals are not enough has to do with
recessive gene borne diseases. For the same reason that you don't have
children with your sister or first cousin if you can help it. In a
large population, the chances of a child dying of a bad recessive gene
are generally small because both parents need to have the bad gene for
you to get it, otherwise you are just a carrier, but in smaller
populations, these genes can become quite common and subsequently
express themselves. Sometimes in horrible ways.
Also, if you go through a bottleneck (like the American Bison) then
you also have problems of all the individuals being susceptible to the
same disease vectors, and you risk extinction even with a larger
population due to a lack of genetic diversity.
You need a bit of gene diversity to maintain a healthy population for
these reasons. There may be more reasons, but these are what I know
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