Speciation

Question 1

Species Definition

Answer 1

Biologically, a species is defined as members of a population that can interbreed under natural conditions

Different species are considered reproductively isolated and cannot exchange genetic information with one another.

For speciation to occur, individuals must become reproductively isolated from the original population and form a new interbreeding population.

Question 2

Reproductive Isolation

Answer 2

Reproductive isolation prevents different species from interbreeding and there are many ways species can be reproductively isolated from each other

Question 3

We sort the types of reproductive isolation into two groups

Answer 3

Prezygotic (prevent fertilization and zygote formation)

Postzygotic (prevent fertilized egg from growing and reproducing)

Question 4

Sympatric Speciation

Answer 4

Sympatric speciation is when a new species forms without geographic isolation

Even though the populations are not separated by physical barriers, other factors such as behaviour differences, or ecological niches prevent them from breeding. This allows the populations to evolve independently.

Question 5

Allopatric Speciation

Answer 5

Allopatric speciation is when new species forms following a period of geographic isolation

Once the populations are separated, the two populations can no longer breed. This allows the two populations to evolve independently.

Question 6

Adaptive Radiation

Answer 6

The relatively rapid evolution of a single species into multiple diverse species, filling a variety of formerly empty ecological niches.

Example: Darwin’s Finches