Genetic variation between organisms of the same species is caused by mutations in genes. Mutations can occur in germ cells, which are passed down to offspring, or in somatic cells. Mutations may be harmful, neutral, or beneficial to an organism's survival and ability to reproduce. Harmful mutations reduce reproduction chances and are less likely to be passed on. Neutral mutations may be passed on over generations without effect. Beneficial mutations increase survival and reproduction, proliferating in future generations.

1. Mutation for Variation

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 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.
GERM CELL
Germ cells are sex cells, like the
sperm and egg.
SOMATIC CELL
Somatic cells are non-sex
cells, like skin or muscle cells.

5. Mutation for Variation
These mutations may be
1) harmful
2) neutral


3) beneficial

to an organism's and its offspring's survival.

6. 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.

7. 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.

8. Mutation for Variation
2) If a neutral mutation is passed-down to the
progeny then its chances of survival and reproduction
are unaffected.

9. Mutation for Variation
2) The neutral mutation will probably be passed down
many generations in some organisms.

10. Mutation for Variation
3) If a beneficial mutation is passed-down then the
progeny have a higher chance to survive and
reproduce.
The opposable thumb mutation
had great advantages over other
animals in that population.

11. 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.