Day 2 - Evolution and Speciation

What does evolution describe?

The cumulative changes in the genetic composition of a species over many successive generations.

What is the result of evolutionary processes?

A great diversity of life on Earth, leading to species that are completely different from their common ancestor.

Who proposed the mechanism of natural selection?

Charles Darwin.

What significant trip did Charles Darwin take in 1836?

He traveled to the Galapagos Islands to study evolution.

What is the title of Darwin's book published in 1859?

On the Origin of Species.

What are Darwin's major findings regarding species?

1. All species tend to over-reproduce. 2. This leads to competition for limited resources. 3. Species show variation among individuals.

What is the process by which individuals best adapted to their environment survive?

Natural selection.

What are the four assumptions of natural selection?

1. Genetic variation exists. 2. Individuals compete for resources. 3. Better-adapted individuals survive and reproduce. 4. Offspring inherit successful characteristics.

What leads to the formation of new species?

Reproductive isolation.

What occurs when populations become separated and can no longer exchange genes?

Reproductive isolation.

What is an endemic species?

A species that is not found anywhere else.

What is allopatric speciation?

Speciation that occurs when two populations are separated by a physical barrier.

What is temporal isolation?

A form of reproductive isolation where organisms with different breeding windows cannot reproduce.

Give an example of habitat isolation.

Different species of fish living in fresh vs. salt water.

How can behavioral changes lead to reproductive isolation?

If a mating ritual changes, such as a dance or song, organisms may not reproduce.

What is anatomical isolation?

A form of reproductive isolation where physical differences prevent mating.