Thanks for stopping by, today we are going
to talk about evolutionary selection, specifically
Natural Selection and Artificial Selection.
But before we get into that, let’s define
selection.
Selection is the process by which inherited
traits are selected for or against and thus
become more or less abundant in the population.
Now let’s apply this definition to natural
selection.
For natural selection to occur in a population
three criteria must be met.
First, there must be variation in the population.
-For example, brown beetles vs green beetles
of the same species.
Second, The trait must be heritable.
Which is to say, it can be passed on from
one generation to the next, through the genes.
Third, more offspring are produced then the
environment can support.
-In other words, a portion of all the offspring
will die because there aren’t enough resources
to support that many offspring in the population.
So in natural selection nature selects which
ones will die based of how their traits “fit”
that environment.
Going back to our beetle example, if there
is a drought one year and all of the green
vegetation dies leaving only brown earth behind,
the brown beetle will thrive while the green
population dwindles.
Nature selected for the brown beetle through
a natural occurrence which favored the brown
beetle.
Now let’s compare this to Artificial Selection
Artificial selection requires only two of
the three criteria; There is variation in
the population and the trait is heritable.
The difference with artificial selection is
that humans decide which traits are passed
on, not nature.
Artificial Selection is used in agriculture
and animal breeding all the time.
People want cows that produce the best and
most milk, so they don’t breed ones that
have low milk production.
Likewise horses have a variety of breeds for
a variety of jobs, breeders use artificial
selection to do this.
All the different breeds of dogs are a result
of this as well.
So natural selection and artificial selection
are really two sides of the same coin.
Both are mechanism of evolutionary selection,
but the process by which they work is slightly different.
I hope that helped, throw any questions you
have in the comments and be sure to subscribe
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Thanks, we’ll catch you next time.
