BIOL 131 Chapter 23 Textbook Vocabulary Notes

Chapter 23-textbook Vocabulary
Population genetics the study of processes
that change the allele and
genotype frequencies in
populations.
Population is a group of individuals
of the same species that
live in the same area at
the same time and can
interbreed.
Natural selection increases the frequency
of certain alleles
the ones that contribute
to reproductive success
in a particular
environment (Ch. 22,
Section 22.3).
Genetic drift causes allele frequencies
to change randomly.
In some cases, drift may
cause alleles that
decrease fitness to
increase in frequency

, Gene flow occurs when individuals
leave one population, join
another, and breed. Allele
frequencies may change
when gene flow occurs,
because arriving
individuals introduce
alleles to their new
population and departing
individuals remove alleles
from their old population.
Mutation modifies allele
frequencies by
continually introducing
new alleles. The alleles
created by mutation may
be beneficial, deleterious
(detrimental), or neutral in
their effects on fitness.
Gene pool They imagined a
hypothetical scenario in
which all of the alleles
from all the gametes
produced in each
generation go into a
single group