Evolution and Population Genetics

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Evolution and Population Genetics I. The Modern
Synthesis II. Beyond the Synthesis III. Types of
Selection Population Ecology Populations are
groups of potentially reproducing individuals in
the same place, at the same time, that share a
common gene pool.
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Population Ecology Populations are groups of
potentially reproducing individuals in the same
place, at the same time, that share a common gene
pool. I. Spatial Distributions A.
Dispersion
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I. Spatial Distributions A. Dispersion -
Regular
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I. Spatial Distributions A. Dispersion -
Regular
- intraspecific competition -
allelopathy - territoriality
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I. Spatial Distributions A. Dispersion -
Clumped
- patchy resource - social effects
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I. Spatial Distributions A. Dispersion -
Random
- canopy trees, later in succession
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I. Spatial Distributions A. Dispersion -
Complexities
- can change with development. Seedlings are
often clumped (around parent or in a gap), but
randomness develops as correlations among
resources decline. regular can develop if
competition becomes limiting.
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I. Spatial Distributions A. Dispersion -
Complexities
- can change with development. Seedlings are
often clumped (around parent or in a gap), but
randomness develops as correlations among
resources decline. regular can develop if
competition becomes limiting. - can change with
population, depending on resource distribution.
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I. Spatial Distributions A. Dispersion -
Complexities
- can change with development. Seedlings are
often clumped (around parent or in a gap), but
randomness develops as correlations among
resources decline. regular can develop if
competition becomes limiting. - can change with
population, depending on resource distribution.
- varies with scale. As scale increases, the
environment will appear more 'patchy' and
individuals will look clumped.
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I. Spatial Distributions A. Dispersion B.
Density
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I. Spatial Distributions A. Dispersion B.
Density 1. Large organisms have lower density
than small organisms.
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I. Spatial Distributions A. Dispersion B.
Density 1. Large organisms have lower density
than small organisms. Damuth (1981) - herbivorous
mammals - log-log relationship - for a 10x
increase in size, about an 80 reduction in
density
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I. Spatial Distributions A. Dispersion B.
Density 1. Large organisms have lower density
than small organisms. Damuth (1981) - herbivorous
mammals - log-log relationship - for a 10x
increase in size, about an 80 reduction in
density White (1985) - Plants - similar trend...
"-3/2 self-thinning law". A stand of dense
seedlings/saplings will die back as they grow to
a sparse stand of mature plants.
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I. Spatial Distributions A. Dispersion B.
Density 1. Large organisms have lower density
than small organisms. 2. High density at center
of range, low density along periphery
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I. Spatial Distributions A. Dispersion B.
Density 1. Large organisms have lower density
than small organisms. 2. High density at center
of range, low density along periphery 3.
Abundant species often have larger ranges
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors - small
range
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors - small
range - narrow environmental tolerances
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors - small
range - narrow environmental tolerances -
small local population
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors D. The Shapes
of Ranges (Brown 1995)
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors D. The Shapes
of Ranges (Brown 1995) - Many abundant species
in North America have ranges oriented E-W. Most
rare species have ranges oriented N-S.
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I. Spatial Distributions A. Dispersion B.
Density C. Extinction Factors D. The Shapes
of Ranges (Brown 1995) - Many abundant species
in North America have ranges oriented E-W. Most
rare species have ranges oriented N-S. Does this
tell us something about their ecologies?
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
So, if a species has an E-W range, it will
probably cross many habitats signifying that the
species is an abundant generalist.
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
So, if a species has an E-W range, it will
probably cross many habitats signifying that the
species is an abundant generalist. If a species
has a N-S distribution, it may be a rare
specialist limited to one habitat zone.
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
So, if a species has an E-W range, it will
probably cross many habitats signifying that the
species is an abundant generalist. If a species
has a N-S distribution, it may be a rare
specialist limited to one habitat zone. An
independent test would be to make predictions
about Europe.
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
An independent test would be to make predictions
about Europe.
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D. The Shapes of Ranges (Brown 1995) - Rivers
and mountains run N-S
An independent test would be to make predictions
about Europe.
Abundant species run N-S, and rare species run
E-W, as predicted by topography and te
generalist-specialist argument.
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I. Spatial Distributions II. Demography
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I. Spatial Distributions II. Demography A.
Life Tables
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I. Spatial Distributions II. Demography A.
Life Tables - used to determine
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I. Spatial Distributions II. Demography A.
Life Tables - used to determine the
survivorship patterns in a population the
growth potential of a population
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I. Spatial Distributions II. Demography A.
Life Tables - used to determine the
survivorship patterns in a population the
growth potential of a population - used by
insurance companies to estimate the age-specific
expected life span of their clients. The
insurance company can then determine how much
they have to charge the client to make a profit.
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I. Spatial Distributions II. Demography A.
Life Tables - used to determine the
survivorship patterns in a population the
growth potential of a population - used by
insurance companies to estimate the age-specific
expected life span of their clients. The
insurance company can then determine how much
they have to charge the client to make a profit.
An old person has a shorter expected life span
than a young person, so they must be charged more
per year in premiums in order to guarantee a
profit to the company.
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I. Spatial Distributions II. Demography A.
Life Tables 1. Components Age classes (x) x
0, x 1, etc. Initial size of the population
nx, at x 0.
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I. Spatial Distributions II. Demography A.
Life Tables 1. Components Age classes (x) x
0, x 1, etc. Initial size of the population
nx, at x 0. Number reaching each birthday are
subsequent values of nx
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I. Spatial Distributions II. Demography A.
Life Tables 1. Components Age classes (x) x
0, x 1, etc. Initial size of the population
nx, at x 0. Survivorship (lx) proportion of
population surviving to age x.
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I. Spatial Distributions II. Demography A.
Life Tables 1. Components Age classes (x) x
0, x 1, etc. Initial size of the population
nx, at x 0. Survivorship (lx) proportion of
population surviving to age x. Mortality dx
dying during interval x to x1. Mortality
rate qx proportion of individuals age x that
die during interval x to x1.
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I. Spatial Distributions II. Demography A.
Life Tables 1. Components Age classes (x) x
0, x 1, etc. Initial size of the population
nx, at x 0. Survivorship (lx) proportion of
population surviving to age x. Number alive
DURING age class x Lm (nx (nx1))/2