Genetic variation within species occurs due to mutations. Mutations can happen in somatic cells or germ cells. Germ cell mutations are passed to offspring and can create new variations within a population. Mutations may be harmful, neutral, or beneficial to an organism's survival and ability to reproduce. Beneficial mutations are more likely to proliferate in future generations as those organisms have a selective advantage. This leads to the adaptation of a species over time through natural selection.
2. Mutation for Variation
All organisms are different, even those of the same
species. This is due to genetic variation.
3. Mutation for Variation
Genetic variation within a species means that genes
have different alleles. Different alleles can by made by
mutation.
4. Mutation for Variation
Mutations may occur in somatic cells or germ cells. Germ
cell mutations are passed along to progeny, creating a
new population.
GERM CELL
Germ cells are sex cells, like the
sperm and egg.
5. Mutation for Variation
Somatic cell mutations will only change the individual
that has the mutation.
SOMATIC CELL
Somatic cells are non-sex cells,
like skin or muscle cells.
6. Mutation for Variation
These mutations may be
1) harmful
2) neutral
3) beneficial
to an organism's and its offspring's survival.
7. Mutation for Variation
1) If a harmful mutation is passed-down then the
progeny is less likely to reproduce successfully.
Female peacocks choose their mates by the colour of their plumage. This
white peacock mutation greatly reduces the chances it will find a mate.
8. Mutation for Variation
1) This means the harmful mutation is also less likely
to be passed along, dying-off with the mutated
organism.
If an animal is born with 3 legs in
the wild, its chances of survival
drop drastically.
9. Mutation for Variation
2) If a neutral mutation is passed-down to the
progeny then its chances of survival and reproduction
are unaffected.
10. Mutation for Variation
2) The neutral mutation will probably be passed down
many generations in some organisms.
11. Mutation for Variation
3) If a beneficial mutation (adaptation) is passed-
down then the progeny have a higher chance to
survive and reproduce (selective advantage).
The opposable thumb mutation
had great advantages over other
animals in that population.
12. Mutation for Variation
3) Future generations will also have this mutation and
will also thrive, having many offspring and
proliferating this mutation.
This lady is resistant to HIV (the AIDS virus) and is more likely to survive
and reproduce in a place where 1 in 4 people are infected with HIV.
13. Think. Pair. Share.
Overuse of antibiotics to kill bacteria leads to antibiotic
resistant strains of bacteria. Propose the way this happens.
16. Evolution
Is the process in which significant changes to genetic traits
of a species occur over time.
End result: The adaptation of a species to its environment.
The GENOME evolves.
17. Evolution
Mutations are the driving force in evolution, but they are
not related to the present needs of an organism; they are
merely the result of chance.
Editor's Notes
For example, human eye colour plays no role in survival.