Speciation

Question 1

What is a species?

Answer 1

A group or population of individuals that are reproductively isolated from other groups and able to produce fertile offspring

Question 2

What is speciation?

Answer 2

The formation of a new species via evolution

Question 3

Describe the two types of speciation

Answer 3

Allopratic - caused by geographical isolation (due to selection pressures)
Sympatric – not caused by geographical isolation (in the same area or habitat)

Question 4

Define adaptive radiation

Answer 4

When a species becomes adapted to its local environment, resulting in changes to allele frequencies of each population

Question 5

Why does sympatric speciation happen?

Answer 5

Reproductive isolation caused by rapid genetic changes such as morphology, behaviour, habitat preferences

Question 6

What are the types of reproductive isolation + examples

Answer 6

Prezygotic (before fertilisation)
- temporal isolation = differences in mating times/seasons
- behavioural e.g. different mating calls
- habitat = different habitat in same area
- morphological
Post-zygotic barriers (after fertilisation)
- wrong/different chromosome number may mean embryo won’t develop or gametes can’t fuse