another strain that migrated into the gene
pool.
Gene Migration
When we deal with a population of plants we
refer to a group of plants that breed within
themselves without any interference from an
outside population. Over time a population will
reach equilibrium and this will be maintained
as long as no other population migrates to this
one. When another population is introduced it
will cause new genes to enter the pool. This is
called Introgression. During the process of
introgression many new traits will pop up in
the population.
Genetic Drift:
If the population is small equilibrium may
be violated. By chance alone certain members
will be eliminated from the population. We will
find that the frequency of an allele will DRIFT
towards higher or lower values.
Non-random mating and Natural selection:
This suggests that something external may
influence a population to a stage where mating
is not random. If some flowers develop earlier
than others then they will gather pollen
earlier than the rest. If some of the males
