Ground Rules, exams, etc. (no

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Second Exam One week from this coming
Thursday Chapters 10, 11, 12, 13, 14, and 15 Can
humans share spaceship earth? Why Can't We
Humans Share Spaceship Earth? The Vanishing Book
of Life on Earth Watch Average Temperatures
1884-2012 Global Warming Watch Domino Effects
Intelligent Design? Handouts 5, 6, and 7Space
Travel Agriculture Economics
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Kc 160 Kb 125
Nc 70 Nb 30
Nc Kc acb Nb acb (Kc Nc)/ Nb
(160 70)/30 90/30 3.00 Nb Kb abc Nc
abc (Kb Nb)/ Nc (125 30)/70
95/70 1.357
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Diffuse competition Ni Ki S aij Nj
Alpha matrices, N and K vectors Matrix Algebra
Notation N K AN Partial derivatives, ?Ni/?Nj
sensitivity of species i to changes in j Jacobian
matrix (community matrices), Lyapunov
stability Evidence for competition in nature
Resource partitioning among sympatric congeneric
pairs Resource Matrices, food, place, time niche
dimensions Complementarity of niche
dimensions Galápagos finches, beak depth, seed
size Character displacement Hydrobia mud
snails Hutchinsonian ratios, Limiting
similarity Corixids, musical instruments, knives,
pots, trikes, bikes Accipter hawks, monitor
lizards
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The ecological niche, function of a species in
the community Resource utilization functions
(RUFs) Competitive communities in equilibrium
with their resources Hutchinsons n-dimensional
hypervolume concept Fundamental and Realized
Niches Niche Breadth Niche Overlap
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Robert H. MacArthur Geographical
Ecology Range of Available Resources Average
Niche Breadth Niche Overlap
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MacArthur, R. H. 1970. Species packing and
competitive equilibrium for many species.
Theoret. Population Biol. 1 1-11. Species
Packing, one dimension
Rate of Resource
Resource Utilization Functions RUFs
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Species Packing , one dimension, two neighbors in
niche space
Three generalized abundant species with broad
niche breadths
Nine specialized less abundant species with with
narrow niche breadths
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Niche Breadth Jack of all trades is a master
of noneMacArthur Levins Theory of Limiting
Similarity
Robert H. MacArthur
Richard Levins
Phenotype
Specialists are favored when resources are very
different
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Niche Breadth Jack of all trades is a
master of none
MacArthur Levins Theory of Limiting
Similarity
Robert H. MacArthur
Richard Levins
Phenotype
Generalists are favored when resources are more
similar
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Niche Dimensionality 1 D 2 Neighbors 2 D
6 Neighbors 3 D 12 Neighbors 4 D 20
Neighbors NN D D2Diffuse
Competition dNi/dt riNi(Ki -Ni -??ij
Nj) dNi/dt 0 when Ni Ki -??ij Nj
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Niche Overlap Hypothesis
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Foraging Tactics and Feeding EfficiencyCosts
and Profits of ForagingAn optimal foraging
tactic maximizes the difference betweenforaging
profits and their costs (net benefit)Food
matter and energy for maintenance and
reproductionHazards exposure to predators,
loss of time for other activitiesSit-and-Wait
ambush predators (e.g. spiders at webs)Widely
foraging active hunters (go out and find
prey)Search Time (per item eaten) versus
Pursuit Time (per item eaten)Search for all
possible prey items, but pursue them one at a
time Prey items can be ranked from most
preferred to least desirable
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Optimal Foraging Theory Economics of Consumer
Choice (R. H. MacArthur) Assumptionsa)
Environmental structure is repeatable, with
statistical expectation of finding a given
resource (habitat, microhabitat, or prey
item)b) Food items can be arranged along a
continuous spectrum, such as by size or energy
rewardc) Similar phenotypes are closely
equivalent in harvesting abilitiesd) Principle
of Allocation applies no one phenotype can be
maximally efficient on all prey typese) An
individuals economic goal is to maximize its
total intake of food resources
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Economics of Consumer ChoiceFour Phases of
Foraging 1) deciding where to search 2)
searching for palatable food items 3) upon
locating a potential food item, deciding whether
or not to pursue it 4) pursuit itself,
with possible capture and eatingSearch and
pursuit efficiencies for each food type in each
habitat are entirely determined by preceding
assumptions about morphology and environmental
repeatability. These efficiencies dictate
probabilities associated with search and pursuit
(phases 2 and 4) . Thus, need to consider only
the two decisions where to forage and which prey
items to pursue (phases 1 and 3 above)
R. H. MacArthur
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Economics of Consumer ChoiceFour Phases of
Foraging 1) deciding where to search 2)
searching for palatable food items 3) upon
locating a potential food item, deciding whether
or not to pursue it 4) pursuit itself,
with possible capture and eatingSearch and
pursuit efficiencies for each food type in each
habitat are entirely determined by preceding
assumptions about morphology and environmental
repeatability. These efficiencies dictate
probabilities associated with search and pursuit
(phases 2 and 4) . Thus, need to consider only
the two decisions where to forage and which prey
items to pursue (phases 1 and 3 above)
R. H. MacArthur
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Economics of Consumer Choice (R. H.
MacArthur)Clearly, an optimal consumer should
forage where its expectation of yield is greatest
-- an easy decision to make, given knowledge of
efficiency probabilities and the structure of the
environment (of course, in reality, animals are
not omniscient and must make decisions based on
incomplete information).The decision as to
which prey items to pursue is also simple. Upon
finding a potential prey item, a consumer has
just two options either pursue it or go on
searching for a better item and pursue that one
instead. Both decisions end in the forager
beginning a new search, so the best choice is
clearly the one that returns the greatest yield
per unit time.An optimal consumer should opt to
pursue an item only when it cannot expect to
locate, catch and eat a better item during the
time required to capture and ingest the first
prey item
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Resource Matrix (n x m matrix) utilization
coefficients and electivities Resource
Consumer Species State 1 2 3 . . . n
1 u11 u12 u13 . . .
u1n 2 u21 u22 u23 . . .
u2n 3 u31 u32 u33
. . . u3n . . .
. . . . . . . . . .
. . . . . . . . . . .
m um1 um2 um3 . . .
umn
Handout 7 Conus Problem
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Niche Dynamics and Niche Dimensionality
Thomas W. Schoener
1-½Spij pik where pij and pik are
the proportions of resource i used
by species j or k respectively
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Unidimensional utilization versus true
multidimensional utilization
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Partial derivatives, ?Ni/ ?Nj sensitivities of
each species to changes in the density of each
other species Jacobian matrix (community
matrices) Lyapunov stability (negative leading
dominant eigenvalue) The ecological niche,
function of a species in the community Resource
utilization functions (RUFs) Competitive
communities in equilibrium with their
resources Within between phenotype components
of niche breadth Hutchinsons n-dimensional
hypervolume concept Fundamental and Realized
Niches Niche dimensionality, unidimensional
shadows misleading Niche overlap
hypothesis Resource matrices
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Resource matrices of utilization coefficients (or
electivities) Disjunct, Abutting, Overlapping,
Included Niches Niche overlap hypothesis Niche
dynamics and niche dimensionality, diffuse
competition Complementarity of niche
dimensions Independence of niche
dimensions Unidimensional estimates of true
multidimensional utilization Niche Breadth
Specialization versus generalization. Similar
resources favor specialists, different resources
favor generalists
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MacArthur Economics of Consumer Choice Robust
theorem Diets contract when prey
abundant MacArthur and Levins limiting similarity
model Ambush versus Active Foragers optimal
foraging Compression Hypothesis Fishers model
of adaptation and deterioration of environment,
p. 92 Periodic tables of niches Thermoconformer
versus thermoregulator continuum Ecological
Equivalents, convergent evolution Adaptive Suite
of horned lizards Convergent evolution,
ecological equivalents (Moloch horridus)
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Adaptation and Deterioration of Environment
Ronald A. Fisher
Non-directed (random) changes in either A or
B are equally likely to reduce the level of
adaptation (d ) when small, but as the
magnitude of change increases, the probability of
improvement diminishes. From Chapter 5, page
92.
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Compression Hypothesis habitats contract,
diets do not
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Empty Niche
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Page 95
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Passive thermoconformer
Page 96
Nephrurus laevissimus
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Active Thermoregulator
Ctenophorus isolepis
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Active Thermoregulator
Ctenophorus isolepis
Thermoconformer
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Ctenotus skinks (Australia)
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Thermoconformer
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Page 106
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Page 106
O
Thermoconformers
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Ten Morphometrics Snout-vent length Tail
length Head length Head width Head depth Jaw
length Forefoot length Foreleg length Hindfoot
length Hindleg length
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Multivariate techniques (principal components,
ordination) Principal Components Analysis
Reduces dimensionality (correlated data)
Changes coordinate system (data positions
unchanged) Log transform data
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First Principal Component Second Principal
Component
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First Two Principal Components reduce variance by
92.4
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First Two Principle Components reduce variance by
92.4
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First Two Principal Components capture 92.4 of
variance
Agama
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Page 343
Moloch
Phrynosoma