University
of London
(University
College London)
BSc
Degree 1999
BIOLOGY
B242: EVOLUTIONARY AND ECOLOGICAL GENETICS
Answer
ONE question from section A, TWO questions from section B, and ALL OF section
C (overleaf).Each section carries 1/3 of the marks on the paper.
Section
A.Answer ONE of questions 1-3.
1.What
is the importance of mathematical models in population genetics and evolutionary
studies?Structure your answer around either: inbreeding and genetic drift,
natural selection at single loci or quantitative genetics.
2.ASympatric
speciation is very unlikely@.Discuss.
3. Discuss,
using examples, the pros and cons of using artificial selection as a model
of natural selection on quantitative traits.
Section
B.Answer TWO of questions 4-8.
4.What
factors might be involved in chromosomal evolution?Discuss your answer
with relation to paracentric inversions or translocations.
5.AGame
theory analysis is irrelevant for evolutionary biologists@.Discuss
and place in the context of ownership and territoriality in nature.
6.Is
the study of hybrid zones the key to speciation?Discuss why or why not.
7.Can
natural selection explain macroevolution?Illustrate your reasoning with
examples.
8.Give
three ways of explaining the evolution of exaggerated male traits, briefly
explain the evidence (or lack of it!) for each, and discuss why female
traits are not usually exaggerated in the same way.
Remember
to answer Section C overleaf!
Section
C.Answer all parts of question 9, even if you cannot do an earlier part.
9.Warning
colour may evolve via Akin
selection@,
in which small local populations evolve new altruistic adaptations because
of a high degree of local relatedness. Genotypic data were collected on
a codominant colour pattern locus in several local subpopulations in a
hybrid zone between two distinct warningly coloured races of the warningly
coloured butterfly Heliconius erato.
Subpopulation
DRyDRy DRyd
dd
1
59 34
6
2
100 42
2
3
41 17
3
a)Estimate
the allele frequencies, (p, q, respectively) for DRy
and d in each subpopulation.Then sum the population genotype totals,
to estimate the overall gene frequencies 
, 
of
the total Ametapopulation@.
b) Calculate
the expected frequencies for the three genotypes under random mating in
the total metapopulation.
c) Use
a chi-square test to find whether there is evidence for deviation from
Hardy-Weinberg in the total metapopulation.
d)Estimate
the value of FST from your data, regardless of whether
or not the deviation from Hardy-Weinberg is significant. You might like
to use the formula FST = 
/(
) to
check your calculations based on the Aheterozygote
deficit@
interpretation of F (if so, you must choose the A
@
rather than the A
@
option on your calculator).
e) What
do the data tell you, if anything, about the possibility of kin selection
or drift being involved in the evolution of warning colour?