Species & Speciation

Question 1

What is Speciation?

Answer 1

The rise of two or more species from one existing species.

Speciation can occur through various mechanisms, including geographic and reproductive barriers.

Question 2

What is the difference between Allopatric and Sympatric speciation?

Answer 2

Allopatric: Geographic barriers separate populations leading to speciation
Sympatric: Something other than a geographic barrier separates populations leading to speciation.

Allopatric speciation typically occurs when populations are physically separated, while sympatric speciation can occur through mechanisms such as polyploidy or behavioral differences.

Question 3

What are Prezygotic Barriers?

Answer 3

Barriers that don’t allow zygote formation.

Examples include behavioral isolation, temporal isolation, and habitat isolation.

Question 4

What are Postzygotic Barriers?

Answer 4

Barriers that occur after zygote formation.

This includes sterile offspring, weak offspring, and no development of the embryo.

Question 5

Give examples of Prezygotic Barriers.

Answer 5

• Behavioral isolation
• Temporal isolation
• Habitat isolation (a niche)

These barriers prevent different species from mating or fertilizing eggs.

Question 6

Give examples of Postzygotic Barriers.

Answer 6

• Sterile offspring
• Weak offspring
• No development of the embryo

These barriers affect the viability and reproductive success of the offspring after fertilization.

Question 7

True or False: Allopatric speciation involves geographic barriers.

Answer 7

True

Allopatric speciation specifically requires a physical separation of populations.

Question 8

Fill in the blank: Sympatric speciation occurs through something other than a _______.

Answer 8

geographic barrier

This can involve factors like behavioral differences or changes in habitat use.