Methods of Evolution

Question 1

What are some Evolution Mechanisms?

Answer 1

1) Random Mutation
2) Genetic Drift
3) The Bottle Neck effect
4) The Founder Effect

Question 2

Random Mutation. How do new traits originate?

Answer 2

Every time Meiosis/Mitosis cycle occurs, small mutations occur the to the DNA. This could often lead to new traits in the offspring.

Question 3

Types of Mutation?

Answer 3

Neutral Mutation: The mutation causes no immediate affect in an organisms fitness.

Harmful Mutation: Reduces an organisms fitness and often results in offspring that do not survive the selective pressures of their environment.

Beneficial Mutation: Increases an organisms fitness, and leads to a competitive advantage… this may result in the organism having greater reproductive success, and passing this new gene to the next generation.

Question 4

What’s Genetic Drift - Random chance?

Answer 4

In small populations, chance can play a significant role in changing allele frequencies.

For example:
if 1 in 50 frogs carry gene X, you would expect that in a population of 10000 frogs, 200 frogs would carry gene X.
If a drastic event kills off half of the frogs, you would expect 5000 frogs, 100 of whom carry gene X.

No Allele Change Frequency.

Question 5

More on Genetic Drift?

Answer 5

There are only 100 frogs in an area, 2 of whom carry gene X.
And half of the frogs die, there is a good chance either:
Both gene X frogs die…. And gene X is eliminated
OR
Both gene X frogs live, and gene X just doubled it’s frequency… and likelihood of being passed on.

Question 6

What’s the Bottleneck Effect?

Answer 6

It is a form of genetic Drift?

It is a dramatic, temporary, reduction in population size usually resulting in genetic drift.

Question 7

What’s the Founder Effect?

Answer 7

It is when a few individuals from a large population leave, or become isolated, establishing a new population.

EX: Finches and Antibiotic Resistant Bacteria.