Construction of a new road system splits a population of a rare snail species into three sub- populations, J, K and L. Each of these populations is reproductively isolated. The table shows the sizes of the three populations immediately after the building of the road
and again ten years later. DNA analysis was used to find:
p the relative frequency of the dominant allele of a gene
q the relative frequency of the recessive allele of this gene.
The three areas of habitat remained the same as each other over the ten year
immediately after road building
after 10 years
population p q size
1000 0.52 0.48 100 0.63 0.37 10 0.20 0.80
population p size
J 1000 0.50 K 100 0.49 L 10 0.40
q
0.50 0.51 0.60
Which statements are supported by this data?
Statement 1: Statement 2: Statement 3:
Natural selection is occurring in populations K and L.
The Founder Effect is strongest in population L.
The observed allele frequency changes result from genetic drift.
A. 1, 2 and 3 C. Only 2 and 3
B. Only 1 and 2 D. Only 1