Natural selection
is the process by
which organisms
with variations
most suited to
their local
environment
survive and leave
more offspring.
One example of
natural selection is
when black moths
survive more than
white moths during
the Industrial
Revolution due to
the soot that
covered many
surfaces. This black
powder allowed the
black moths to
camouflage more
easily than the
white moths.
Fitness
Fitness describes how well an organism can
survive and reproduce in its own environment.
Animals with high fitness survive,
An example of animals with high fitness
would be bunnies. Because they reproduce
in high rates. Examples of animals with low
fitness would be animals that are
endangered.
Adaptations
Adaptation is any heritable
characteristic that increase an
organism's ability to survive and
reproduce in its environment.
One example of adaptation is the colors of
animals that make camouflage or mimicry
possible. Another example of adaptation can be
shown in behaviors of predators when catching
prey.
Mutations
Mutations are variations and heritable changes in
genetic information.
Examples of point mutations are substitutions,
insertions, and deletion. Examples of
Chromosomal mutations are deletion,
duplication, inversion, and translocation.
Lethal Alleles
Lethal alleles are alleles that
are deathly when present in a
gene. If the lethal allele is
recessive and present in a
heterozygous gene, it does not
have deathly effects because
the dominant allele dominates
over the recessive allele. Thus,
lethal alleles that are recessive
are only deathly when they are
homozygous. On the other
hand, lethal alleles that are
dominant can be deathly in
both homozygous and
heterozygous genes.
some examples of
recessive lethal alleles
can be found in the genes
of cystic fibrosis and
sickle-cell anemia. One
example of dominant
lethal alleles can be found
in the genes of
Huntington's disease.