meb

Question 1

Speciation

Answer 1

the formation of species that increases the range of organisms on earth, increasing biodiversity. Extinction is the loss of species that decreases the range of organisms on earth, decreasing biodiversity

Question 2

Temporal isolation

Answer 2

breeding or flowering at different times of the year where different populations or species may produce gametes at different times preventing successful reproduction

Question 3

Behavioural isolation

Answer 3

specific courtship behaviours or different pollinators where different populations or species behave differently or utilise different pollinators resulting in mating or pollination not occurring, so no successful reproduction occurs

Question 4

Mechanical/structural isolation

Answer 4

incompatible sex organs or chemicals that prevent gametes from individuals of different populations or species from fertilising

Question 5

Ecological isolation

Answer 5

occupying different habitats or niches in the same environment decreases the chance of meeting up with a potential mate in different populations or species

Question 6

Hybrid isolation (post-zygotic)

Answer 6

when different populations or species do manage to reproduce and produce hybrid offspring, however, the hybrid is infertile and unable to reproduce

Question 7

Punctuated Equilibrium

Answer 7

According to punctuated equilibrium, evolution is not always gradual as proposed by Darwinism.

Evolution may involve long periods of time where species do not change or change very little (known as equilibrium).

This alternates with (is punctuated by) short periods of time where rapid changes occur through natural selection and speciation.

As a result, new species are formed in a short period of time, relative to the long periods of no/little change.

This is supported by the absence of transitional fossils (usually termed missing links) indicating the period of rapid change.