Speciation And The Generation Of Biodiversity

Question 1

What is prezygotic isolation?

Answer 1

Barriers before fertilisation

Question 2

What are the 5 prezygotic isolation examples?

Answer 2

Temporal (don’t meet in time)
Ecological (don’t meet in space)
Behavioural (don’t want to mate)
Mechanical (don’t physically mate)
Gametic (gametes can’t find and fuse)

Question 3

What does postzygotic isolation mean?

Answer 3

Barriers after fertilisation

Question 4

Examples of postzygotic isolation (2)

Answer 4

Less hybrid variability so babies die

Less hybrid fertility so babies are sterile

Question 5

Why are mammals not tolerant of hybridisation?

Answer 5

Mammals get pregnant and body rejects it as it is “non-self”.

Also need to interface with mum

Question 6

What increases speciation?

Answer 6

Colonising new habitats

Question 7

How do species form? (4)

Answer 7

Allopathic speciation
Germinate species
Ecological isolation
Can’t be internally driven (mutation)

Question 8

What’s bad about postzygotic isolation? (4)

Answer 8

Genetic incompatibilities in cellular/developmental mechanisms

Processes involved in making sperm

Unselected incompatibilities (accumulation of mutations)

Can be ecological