Speciation, Isolation, Diversification

Question 1

Diversification:

Answer 1

the evolutionary change of a species

Question 2

Divergent evolution:

Answer 2

produces homologous structures

Question 3

Homologous structures:

Answer 3

• anatomical structures that have the same origins but have evolved different functions

Question 4

Adaptive radiation:

Answer 4

• a type of divergent evolution regarding species adapting to different environments
• involves rapid speciation that often occurs after an extinction event

Question 5

Convergent evolution:

Answer 5

when separate species which share a similar niche evolve similar features. These features are purely phenotypic and superficial however

Question 6

Coevolution:

Answer 6

evolutionary change where a change in a feature of one species acts as selection pressure for a change in a feature of another species

Question 7

Parallel evolution:

Answer 7

occurs when two or more related groups evolve along similar lines independently

Question 8

Key mechanisms of isolation include (out of 5):

Answer 8

• Geographic
• Reproductive
• Spatial
• Temporal
• Behavioural

Question 9

Isolating mechanism:

Answer 9

a factor that prevents members of populations of the same species, or different members of different species, from breeding together

Question 10

Prezygotic:

Answer 10

before the egg is fertilised

Question 11

Postzygotic:

Answer 11

after the egg is fertilised

Question 12

Prezygotic isolating mechanisms include (out of 5):

Answer 12

• Geographical isolation
• Reproductive isolation
• Gametic isolation
• spatial/ecological isolation
• temporal isolation
• behavioural isolation

Question 13

Reproductive isolation:

Answer 13

differences in structure of the external reproductive organs stop act of reproduction

Question 14

Geographical isolation:

Answer 14

resulting from physical barriers such as mountains etc.

Question 15

Gametic isolation:

Answer 15

incompatibility of gametes

Question 16

Spatial/ecological isolation:

Answer 16

if species occupy different niches and therefore can’t reproduce

Question 17

Temporal isolation:

Answer 17

results from breeding behaviour occurring at different, non-overlapping times

Question 18

Behavioural isolation:

Answer 18

results from differences in behaviour, typically mating behaviour such as courtship

Question 19

Postzygotic isolating mechanisms include (out of 3):

Answer 19

• Hybrid inviability
• Hybrid breakdown
• Hybrid sterility

Question 20

Hybrid inviability:

Answer 20

occurs when the fertilised egg does not develop as the chromosomal incompatibility leads to developmental problems causing a very low change of offspring survival

Question 21

Hybrid breakdown:

Answer 21

occurs when the hybrid reaches maturity and is able to breed, but any generations after that are sterile

Question 22

Hybrid sterility:

Answer 22

occurs when the hybrid reaches maturity but is sterile and cannot breed

Question 23

Allopatric:

Answer 23

process by which new species are formed from one common ancestor while in different geographical areas

Question 24

Sympatric:

Answer 24

the process by which new species are formed from one common ancestor while in the same geographical area

Question 25

Parapatric:

Answer 25

the process by which species vary along a cline, which is a geographical region that shows a gradient in characteristics

Question 26

Speciation:

Answer 26

the process by which one species splits into two or more separate species