thanks for stopping my today we're going
to talk about genetic drift. So genetic
drift is a mechanism of evolution that's
responsible for random changes in a gene
pool.
It happens to all populations but
has a much more visible and drastic
effect in small populations right it's
driven by chance and not selection so
evolutionary Fitness doesn't matter here
it's all random natural selection
doesn't come into play when we're
looking at genetic drift and there's two
main types of genetic drift you have the
founder effect and the bottleneck effect
and we'll look at some examples of both of these.
So let's say that you have a
town called Darwinville and you have
100 people that live in this town and
those 100 people 95 of them are
right-handed and the other five are left-handed
 
let's say a small group of about four
people from this Darwinville decide to
move away and settle some new
uninhabited land and let's say these
four individuals happen to all be left-handed.
Their gene pool is now
drastically different from the group
they left because all their descendants
will be left-handed and this is an
example of the founder effect on a small
group leaves from a population and
carries with it a new gene frequency
let's go back to our town of Darwin
ville where we now have 96 people and
only one lefty. Let's say a freak storm
comes through and kills 75 of the
residents of Darwinville including our
last left-handed person and all
remaining recessive left-handed alleles.
and then the new population now 21
individuals will have no left-handed
posterity
from this point on so this is an example
the bottleneck effect when a random is
random reduction of the population due to some random event.
So hopefully this
video and these examples were helpful
you can see the link in the
description for more information and for
more examples on genetic drift or you
can meet up in the comments if you have
any questions be sure to check out my
other videos and let me know if you have
a specific video that you want me to
make thanks for watching I'll catch next time
