Download BIOLOGY 262, P B

BIOLOGY 262, PRINCIPLES OF BIOLOGY: ORGANISMIC BIOLOGY
ECOLOGY & EVOLUTION REVIEW QUESTIONS
Review Questions
1. For a population undergoing logistic growth with a starting size of 100000, an intrinsic rate of increase of 0.10,
and a carrying capacity of 200000, what is the population size after 1 year? 2 years? 3 years?
2. In a suburban area there were three patches of unmodified habitat supporting a threatened species of small
lizard. A new shopping center was built destroying one of the patches of habitat (and therefore all the
lizards in that patch as well. Over the period of a few years all the lizards in the other two patches that
were not altered by the new shopping center disappeared. What most likely happened? How might a
detailed population study of the patches before construction began have predicted that this would occur?
3. Two populations of white clover were sampled for their genotype for a cyanide production gene. The allele C
increases cyanide production by the plants. The allele c blocks cyanide production. Cyanide discourages
grazers but harms or kills the plant when the temperature dips below freezing.
population
St. Petersburg, Russia
Istanbul, Turkey
CC individuals
Cc individuals
cc individuals
climate
0
200
800
cold
500
450
50
warm
(a) Calculate the Hardy-Weinberg expected numbers for both populations and indicate if each is at HardyWeinberg equilibrium.
(b) Interpret your results above in terms of evolution of the two populations using all the information above.
Briefly, what evolutionarily is happening to the allele frequencies in each population?
4. You study the adult hemoglobin genes in a human population in Cameroon, Africa. The number of
individuals with each genotype is HbaHba = 2225, HbaHbs = 998, HbsHbs = 1. Hba is the allele
for “normal” hemoglobin. Hbs is the allele for “sickled” hemoglobin. (a) Is this hemoglobin gene
at Hardy-Weinberg Equilibrium in this population? (show your calculations) (b) Based on the
lectures in class what do you know about the affects of having different hemoglobin genotypes
on the health of individuals? (c) Based on your knowledge of this genetic system which
microevolutionary process (if any) likely is affecting this population? (d) Given the results of
your population genetic analysis of this population what conclusion could you draw about
infection disease in this population?
5. You study the cystic fibrosis genes in a human population in Ireland, Europe. The number of
individuals with each genotype is CC = 5435, Cc = 55, cc = 4. C is the allele for “normal” lung
function. c is the allele for impaired (c.f.) lung function. (a) Is this cystic fibrosis gene at HardyWeinberg Equilibrium in this population? (show your calculations) (b) Which
microevolutionary process (if any) likely is affecting this population? (c) Explain in which way
this system differs from the sickle cell disease example in 9 above?
6. Coherently explain what the assumptions of the Hardy-Weinberg equation are. Then explain why
these assumptions are not reasonable for most biological systems. Finally, explain how the
equation is useful.
7. Use the data below to construct a phylogenetic tree of the species in the left column. Show the derived traits
on your phylogenetic tree. OG = Outgroup
horns
stomach
chambers
carnassial
teeth
pouch
hooves
Antelope
present
4
absent
absent
present
Cow
present
4
absent
absent
present
Whale
absent
4
absent
absent
absent
Walrus
absent
1
present
absent
absent
Wolf
absent
1
present
absent
absent
Opossum OG
absent
1
absent
present
absent
8. Use the data below to construct a phylogenetic tree of the mythical species in the left column. Show the
derived traits on your phylogenetic tree.
wings
warts
nose
ear tips
eye color
size
garden gnome
absent
no warts
stubby
rounded
green
small
field gnome
absent
no warts
stubby
rounded
green
small
eastern pixie
present
no warts
slender
rounded
green
small
western pixie
present
no warts
slender
pointed
golden
small
island pixie
present
no warts
slender
pointed
golden
small
troll (outgroup)
absent
warts
slender
rounded
green
large