Evolution

Question 1

Behavioural Isolation

Answer 1

Pre-Fertilization
Prevention of Mating

changes to behaviour (e.g. song/mating ritual changes) cause species to stay apart

Question 2

Temporal Isolation

Answer 2

Pre-Fertilization
Prevention of Mating

changes in timing (e.g. season species is active or diurnal/nocturnal) cause species to stay apart

Question 3

Habitat Isolation

Answer 3

Pre-Fertilization
Prevention of Mating

change in habitat (e.g. preference to dry vs. moist area) causes species to stay apart

Question 4

Mechanical Isolation

Answer 4

Pre-Fertilization
Prevention of Fertilization

parts (e.g. genitals, body shape) don’t fit, so species prevented from mating

Question 5

Gametic Isolation

Answer 5

Pre-Fertilization
Prevention of Fertilization

the gametes (e.g. sperm/eggs) can’t fuse, preventing fertilization

Question 6

Hybrid Inviability

Answer 6

Post-Fertilization
Prevention of Hybrids

mating occurs, but embryo aborts/miscarriages before birth

Question 7

Hybrid Sterility

Answer 7

Post-Fertilization
Prevention of Hybrids

mating occurs, but offspring is sterile

Question 8

Hybrid Breakdown

Answer 8

Post-Fertilization
Prevention of Hybrids

mating occurs but offspring can only have offspring with pure species of its parents (F2 generation not viable)