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0:00
Hello, my name is Paul Verdu.
I am a tenured researcher
at the CNRS
hosted at the Museum of Mankind
in Paris, France,
and today I am going to talk to you
about human admixture.
0:13
[Genetic admixture processes:
a population genetics perspective]
We will first investigate
genetic admixture processes
from a theoretical
and a population genetics perspective.
Then, we will talk and investigate
human admixture as a phenomenon
through isolation,
migration, and in particular,
sociocultural behavior.
Finally, we will illustrate
these points
with the case study
of genetic admixture
between "Pygmy"
and "non-Pygmy" populations
from Central Africa.
0:42
Genetic admixture processes:
a population genetics perspective.
0:49
What is genetic admixture?
Admixture between populations
can be classically defined
as exchanges of genes
between two
or more previously
reproductively isolated populations.
In this cartoon,
you can see population one
and population two,
which we will call source populations.
They are isolated,
but at some point in time—
time, T here—
they send migrants, or genes,
with proportion s1 and s2
in this cartoon,
with s1 plus s2 equals one,
to form a third population
that we'll denote as admixed.
In particular, admixed individuals
have a fraction of their genome,
denoted H, that is derived
from the gene pool
of one
of the previously isolated source populations.
Be careful here—admixed individuals,
per se, are individuals
who have a fraction of their genome
coming from each one
of the source populations,
so H for the admixed individual
is between zero and one.
The admixed population, per se,
can withhold individuals
that are not genetically admixed
but that are just migrants
from the first
or the second source population.
