Unit 4: Mechanisms of Evolution
The Evolution of Populations
group of individuals of a species.
Natural selection acts on individuals, but
, based on
that are inherited over generations.
As a population evolves, its heritable variation is reflected in change of
A non-evolving population reaches the
due to Mendelian
At Hardy-Weinberg equilibrium, the distribution of 2
in a population can be modeled by two
Natural populations may
if conditions deviate from the Hardy-Weinberg model.
in small populations tends to
genetic variation. In very small populations the
can contribute to severe loss of genetic diversity.
from the movement of individuals or gametes between populations can affect allele frequencies and tends to
genetic differences between
is the basis for
selection, and results in unequal reproduction of alleles.
Sexually reproductive organisms often exhibit
mating behaviors such as
is the major mechanism that drives adaptive
Causes of Evolutionary Change:
Apr 16, 2011