Transcript Review

Lecture Questions/Key concepts to review
-Selective Sweeps
-Selection-Drift Balance – Wright’s model
-Gene Flow vs Genetic Drift
-Example of the coal mine
-Molecular Clock
Kirkpatrick 2013
Jeopardy Instructions
• Break into groups.
• Come up with team names.
• Pull out a notebook or some paper to write
your answers on.
• Hold up the paper with the answer on it
when you have finished (no need to answer
with “what is...”, “who is...”, etc.)
Evolution
Human
Diversity
MATH
Natural Selection
and Migration
Cultural
Impact
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Evolution
– 10 Points
QUESTION:
Define “evolution” and its 4 major forces.
ANSWER:
Changes in allele frequencies over time within a
population.
(1) Natural Selection, (2) Genetic Drift, (3) Mutation,
(4) Gene Flow aka Migration
Evolution
– 20 Points
QUESTION:
If population size increases the strength of genetic drift
_______ while natural selection _________.
ANSWER:
If population size increases the strength of genetic drift
decreases while natural selection increases.
Evolution
– 30 Points
QUESTION:
What statistic did Cavalli-Sforza examine in the
Parma Valley between villages? Define this
statistic.
ANSWER:
FST aka Wrights Fixation index, F statistic, Inbreeding
coefficient. It is a measure of variability between
populations.
Evolution
– 40 Points
QUESTION: DAILY
DOUBLE
What “neutral”
phenomenon does this
graph show geographic
distance and human skull
variation?
ANSWER:
Isolation by distance
Evolution
– 50 Points
QUESTION:
Name the 3 most important scientific contributors to the
“Modern Synthesis” aka when population geneticists
integrated natural selection, Mendelian genetics, and
micro and macroevolutionary ideas together to explain
evolution.
ANSWER:
Sewall Wright, Ronald Fisher, JBS Haldane
Human Diversity
– 10 Points
QUESTION:
What is the name of the model that describes human
evolution as a result of migration from a source
population being repeated with each new resulting
population eventually leading to a major loss of genetic
diversity?
ANSWER:
Serial Founder
Human Diversity
– 20 Points
QUESTION:
All non-African human populations are thought to share
a common ancestor ______ years ago.
ANSWER:
60,000 to 70,000
Human Diversity
– 30 Points
QUESTION:
All Native Americans share __ mitochondrial
haplotypes and __ Y haplotypes. This is part of a
larger __________ found in Siberia.
ANSWER:
All Native Americans share 5 mitochondrial
haplotypes and 2 Y haplotypes. This is part of a
larger haplogroup found in Siberia.
Human Diversity
– 40 Points
QUESTION:
What type of selection is evident from increased malaria
resistance in Africa for heterozygotes of the sickle cell
allele?
ANSWER:
Frequency Dependent Selection (this is also a case of
overdominance or heterozygote advantage)
Human Diversity
– 50 Points
QUESTION:
Name 2 candidate genes examined in the research study
about human pigmentation and selection.
ANSWER:
–TYR, tyrosinase is an enzyme makes early forms of pigment
–MATP helps traffic this enzyme to right part of melanocyte
(melanosomes)
–OCA2 is an ion transporter on the surface of melanosomes, and
helps maintain their pH
–SLC24A5 , Ca2+ transporter that regulates melanosome function
–MC1R, receptor that triggers deposition of dark eumelanin
–ASIP, agouti-signaling peptide, is a natural antgonist to MC1R
and blocks effects of MSH
MATH
– 10 Points
QUESTION:
What is the mathematical equation for broad sense
heritability? What do the variables mean?
ANSWER:
H2 = VG /VP
Genetic variation / phenotypic variation
MATH
– 20 Points
QUESTION:
If there are 15 p alleles and 25 q alleles in a population
of 20, what is the frequency of q? What’s the expected
Heterozygosity?
ANSWER:
q = 25/40 = 0.625
2pq = 0.46
MATH
– 30 Points
QUESTION:
What simple equation allows you to detect natural
selection from genetic data? What do the variables stand
for?
ANSWER:
dN/dS
Nonsynonymous / synonymous mutations
MATH
– 40 Points
QUESTION: DAILY DOUBLE
The number of new alleles within a population can be
determined by what equation and variables?
ANSWER:
# new alleles = µ * Ne * # generations
MATH
– 50 Points
QUESTION:
What is the equation for genetic variance?
Define the variables.
ANSWER:
Vg = Va + Vd + Vei
Va : additive variance
Vd : dominance variance
Vei : epigenetic variance
Natural Selection
– 10 Points
QUESTION:
What type of selection is
show by the second graph?
ANSWER:
Disruptive
Natural Selection
– 20 Points
QUESTION:
What evolutionary forces leave behind a pattern on the
entire genome?
ANSWER:
Neutral forces like drift and gene flow happen on the
whole genome, while selection acts only on those genes
that contribute to a phenotype.
Human Migration
– 30 Points
QUESTION:
Briefly, describe the experiment to detect who was first
to admix with the Rapanui people in Moreno-Mayar et
al paper.
ANSWER:
(1) ADMIXTURE analysis at K=4 to find the native
american and European Component
(2) Analyze the size of the tracts of ancestry.
(3) Use a fancy likelihood-model to determine the time
to admixture.
Natural Selection
– 40 Points
QUESTION:
What do you call the phenomenon of a new mutation
increasing rapidly in frequency and dragging along
nearby variants with it? Name 1 piece of genetic
evidence supporting this phenomenon.
ANSWER:
Selective Sweep
(1) Low variation near selected sequence.
(2) Long common haplotypes surrounding selected
sequence.
Natural Selection
– 50 Points
QUESTION:
What is the major assumption or generalization we
make in regards to mutations?
ANSWER:
That they normally are either neutral or very weakly
deleterious.
Cultural Impact
– 10 Points
QUESTION:
When and where do we think agriculture emerged first?
ANSWER:
About 11,000 years ago in the Fertile Crescent.
Cultural Impact
– 20 Points
QUESTION:
What two groups of humans lack independently evolved
genes that protect against diabetes putting them at
greater risk of disease from a carbohydrate right diet?
ANSWER:
Amerindians and Australian Aborigines
Cultural Impact
– 30 Points
QUESTION:
What do you call the genetic modifier regulating lactase
persistence? What type of evolution is lactase
persistence an example of?
ANSWER:
A non-coding enhancer; convergent evolution
Cultural Impact
– 40 Points
QUESTION:
Agriculture was invented independently by what
groups? What crops did they create?
ANSWER:
Middle Easterners: wheat, barley, lentils, peas
Sub-Saharan Africans: yams & sorghum
Amerindians: potatoes & corn
Cultural Impact
– 50 Points
QUESTION:
What was the average decrease in height associated with
the shift to agriculture?
ANSWER:
5 inches