Nothing makes sense but in the light of

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Nothing makes sense but in the light
of evolution --Theodosius Dobzhansky
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1. Outline of course grading organization 2.
Talk about domestication disease evolution
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Grading
There will be multiple choice questions
2/3 There will be problem or short answer
questions as the material permits
The average grade on exams is 50 The numerical
grade tells you little about the letter grade
Grades will be standardized in a way that
allows for differences in test difficulty, etc.
There is always a normal distribution of grades I
standardize the scores using a z-statistic Your
standardized score will depend on the mean and
the variance of the test scores
The mean grade for this course will be in the C
range
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Organization of Topics in the Course
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Genetic Mechanisms of Evolution population
genetics quantitative genetics
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Genetic Mechanisms of Evolution population
genetics quantitative genetics
Theory of Adaptation
Speciation
Macroevolution
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Theory of Adaptation
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Genetic Mechanisms of Evolution population
genetics quantitative genetics
Theory of Adaptation
Speciation
Macroevolution
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Speciation
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Genetic Mechanisms of Evolution population
genetics quantitative genetics
Theory of Adaptation
Speciation
Macroevolution
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Macroevolution
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Genetic Mechanisms of Evolution population
genetics quantitative genetics
Theory of Adaptation
Speciation
Macroevolution
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Domestic dogs are extremely variable
Domesticated from wolves
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When were dogs domesticated? Where were they
domesticated? How many times were they
domesticated?
Dogs are the first domesticated species The
oldest remains of true dogs are 12-14,000 years
old from Eurasia and 9-10,000 from N. America
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Phylogeny of dogs
clades
Genetic Evidence for an East Asian Origin of
Domestic Dogs Peter Savolainen, Ya-ping
Zhang, Jing Luo, Joakim Lundeberg, and Thomas
Leitner Science Nov 22 2002 1610-1613.
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Coyote
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Phylogeny from pre-Columbian dog remains
Latin American
Alaskan
Eurasian Wolves, lu
American Wolves, lu
Modern dogs, D
Humans colonizing America 12-14,000 years ago
brought dogs with them
Ancient DNA Evidence for Old World Origin of New
World Dogs. Jennifer A. Leonard, Robert K.
Wayne, Jane Wheeler, Raúl Valadez, Sonia Guillén,
and Carles Vilà Science Nov 22 2002 1613-1616.
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When were wolves domesticated?
Before 14,000 BP Where were they domesticated?
East Asia How many times were they Once,
with occasional domesticated? wolf
(female) hybrids
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What happens during domestication?
1. Animal/plant chosen for advantageous
traits. 2. Animal/plant deliberately bred for
traits.
How do dogs differ from wolves? Bark They wag
tails Their tails are curved Jaw
differences They are hunting companions
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Dogs are highly attuned to the behavior of people
Social cues about the location of food
The Domestication of Social Cognition in Dogs.
Brian Hare, Michelle Brown, Christina
Williamson, and Michael Tomasello. Science Nov
22 2002 1634-1636.
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Corn is not so simple
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There are variants that occur naturally The
variants can be inherited Some variants perform
better in some environments Better variants
become more common
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why should we care about evolution?
-- emergent diseases -- antibiotic resistance
in bacteria -- pesticide resistance of
mosquitoes
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1. Transformation of a lineage over time
-- usually short time scale -- test with
experiments or the comparative method
2. Diversification of one lineage into several
-- often long time scale -- usually not
experimentally tractable -- phylogeny
reconstruction
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HIV as an evolutionary case study Adaptation -
how populations change through time in
response to environmental change (lineage
transformation) -- AZT resistance -- evolution
of lethality Diversification - how new forms
arise -- origins of HIV -- evolution of
lethality
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HIV
retrovirus (RNA) attacks T cells (immune
system) normal 800-1000 cells/ml AIDS
lt200 cells/ml death by secondary
infection b/c immune system destroyed

reduce recognition of virus as foreign
destruction of T cells changes in virus
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HIV is a retrovirus -- reverse transcriptase
AZT azidothymidine vs normal thymidine
stop codon
is AZT resistance due to infection with a
different HIV ?
1. resistant individuals often have the same
change in the reverse transcriptase 2. stopping
AZT causes resistance to decline
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HIV quickly becomes resistant to drug treatments
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Evolution of resistance to AZT
reverse transcriptase errors
non-mutant mut1 mut2 mut3
mut4 mut5
killed by X slightly X X
X AZT resistant
non- resistant mut2.1 mut2.2 mut2.3
X X X
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effectiveness and speed of process -- rate
of mutation (m 1/yr) -- strength of
selection
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Influenza RNA virus Spreads rapidly
Human immune system affects flu
Time period 1985-1996
HA1 gene (Hemagglutinin) Type A subtype H3