7.3: Speciation

Question 1

Explain the process of Speciation using the acronym MVIENS

Answer 1

M - A DNA MUTATION occurs -> new allele
V - Leading to genetic VARIATION -> phenotypic variation within the population
I - Population is split into 2 sub-populations that can no longer interbreed - reproductively ISOLATED
E - Differing ENVIRONMENTS result in different selective pressures on each sub-population, as mutation is random, different mutations occur in the different populations
N - NATURAL SELECTION - change in allele frequencies in each sub-population
S - the 2 sub-populations can no longer interbreed to produce fertile offspring -> new species has been made -> SPECIATION has occured

Question 2

What is the difference between allopatric and sympatric speciation

Answer 2

allopatric -> caused by geographical separation
sympatric -> same geographical location

Question 3

Define reproductive isolation

Answer 3

no gene flow between the two populations

Question 4

What is genetic drift and when is it significant - give an example

Answer 4

Genetic drift is when there is a change in allele frequency in the population due to random chance
This can be a significant factor in SMALL populations - if q = 0.01, in a population of 1 million, 10000 individuals possess the allele, but in a population of 100, only one has it. Genetic drift is faster in a small population