Ground Rules, exams, etc. (no

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Lack - Avian clutch size and parental care Great
tit, starling, chimney swift Delayed reproduction
in seabirds, especially albatrosses Latitudinal
Gradients in Avian Clutch Size Daylength
Hypothesis Prey Diversity Hypothesis Spring
Bloom or Competition Hypothesis Nest Predation
Hypothesis (Skutch) Hazards of Migration
Hypothesis Evolution of Death Rates Senescence,
old age, genetic dustbinMedawars Test Tube
Model recession of time of expression of
overt effects of a detrimental allele
precession of time of expression of effects of a
beneficial allele S - shaped sigmoidal
population growth Verhulst-Pearl Logistic
Equation dN/dt rN (K N)/K
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Some of the Correlates of r- and K-Selection
____________________________________
__________________________________________________
_


r-selection
K-selection ____________________________________
__________________________________________________
_

Climate Variable and unpredictable
uncertain Fairly constant or predictable
more certain Mortality Often catastrophic,
nondirected, More directed, density
dependent density independent
Survivorship Often Type III
Usually Types I and II Population size Variable
in time, nonequilibrium Fairly
constant in time, ibrium usually well below
equilibrium at or near carrying
capacity of environment carrying
capacity of the unsaturated communities or
environment saturated portions
thereof ecologic vacuums communities
no recolonization recolonization each year
necessary Intra- and inter- Variable,
often lax Usually keen specific
competition Selection favors 1. Rapid
development 1. Slower development 2. High
maximal rate of 2. Greater competitive
ability increase, rmax 3. Early
reproduction 3. Delayed reproduction 4. Small
body size 4. Larger body size 5. Single
reproduction 5. Repeated reproduction 6. Many
small offspring 6. Fewer, larger progeny Length
of life Short, usually less than a year Longer,
usually more than a year Leads
to Productivity Efficiency Stage in
succession Early Late, climax _________________
_________________________________________________
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Mola mola
Dr. Kirk Winemiller Texas A M. Univ.
Sturgeon
Gambusia
Sharks, skates, and Rays
Mosquito Fish
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Sequoia Tree
Dr. Kirk Winemiller Texas A M. Univ.
Dandelion
Cocoa Nut Tree
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Population Regulation Ovenbird example
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Frequencies of Positive and Negative Correlations
Between Percentage Change in Density and
Population Density for a Variety of Populations
in Different Taxa ________________________________
_________________________________ Numbers
of Populations in Various Categories
Positive Positive Negative Negative
Negative Taxon (Plt.05) (Not sig.) (Not sig.)
(Plt.10) (P lt .05) Total
_________________________________________________
________________

Inverts 0 0
0 0 4 4 Insects 0 0
7 1 7 15 Fish 0 1
2 0 4 7 Birds 0 2 32
16 43 93 Mammals 1 0 4
1 13 19 Totals 1 3
45 18 71 138 _____________________________
_____________________________________ Homo
sapiens
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http//www.commondreams.org/view/2011/03/07-0
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Hudson Bay Company
Notice apparent 10-year periodicity
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Hudson Bay Company
Hudson's Bay was incorporated on 2 May 1670, with
a royal charter from King Charles II. The charter
granted the company a monopoly over the region
drained by all rivers and streams flowing into
Hudson Bay in northern Canada. The area gained
the name "Rupert's Land" after Prince Rupert,
the first governor of the company appointed by
the King. This drainage basin of Hudson Bay
constitutes 1.5 million square miles, comprising
over one-third of the area of modern-day Canada
and stretches into the present-day north-central
United States. The specific boundaries were
unknown at the time. Rupert's Land would
eventually become Canada's largest land
"purchase" in the 19th century.
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Population Cycles

• Sunspot Hypothesis
• Time Lags
• Stress Phenomena Hypothesis
• Predator-Prey Oscillations
• Epidemiology-Parasite Load Hypothesis
• Food Quantity Hypothesis
• Nutrient Recovery
• Other Food Quality Hypotheses
• Genetic Control Hypothesis

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http//www.commondreams.org/view/2011/03/07-0
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Sunspot Hypothesis (Sinclair et al. 1993. Am.
Nat.) 10 year cycle embedded within 30-50 year
periods Maunder minimum 1645-1715 Three periods
of high sunspot maxima 1751-1787 1838-1870
1948-1993 Canadian Government survey
1931-1948 Hare cycle synchronized across North
America Yukon 5km strip, tree growth rings (N
368 trees) One tree germinated in 1675 (gt300
years old) Hares prefer palatable shrubs, but
will eat spruce leaving dark tree ring marks
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CH4
C
C02
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Population Cycles

• Sunspot Hypothesis
• Time Lags
• Stress Phenomena Hypothesis
• Predator-Prey Oscillations
• Epidemiology-Parasite Load Hypothesis
• Food Quantity Hypothesis
• Nutrient Recovery
• Other Food Quality Hypotheses
• Genetic Control Hypothesis

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Other Food Quality Hypotheses Microtus
palatability ltgt toxic (Freeland
1974) Snowshoe
hares Plant chemical defenses against
herbivory
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Chittys Genetic Control Hypothesis
Could optimal reproductive tactics be involved in
driving population cycles?
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Population Cycles

• Sunspot Hypothesis
• Time Lags
• Stress Phenomena Hypothesis
• Predator-Prey Oscillations
• Epidemiology-Parasite Load Hypothesis
• Food Quantity Hypothesis
• Nutrient Recovery
• Other Food Quality Hypotheses
• Genetic Control Hypothesis

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Social Behavior Hermits must have lower
fitness than social individuals Clumped, random,
or dispersed (variance/mean ratio) mobility
motility vagility (sedentary sessile
organisms) Use of Space Philopatry Fluid
versus Viscous Populations Individual
Distance, Daily Movements Home
Range Territoriality (economic
defendability) Resource in short
supply Feeding Territories Nesting
Territories Mating Territories
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V
Net Benefit
V
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Sexual Reproduction Monoecious versus
Diecious Evolution of Sex gt Anisogamy Diploidy
as a fail-safe mechanism Costs of Sexual
Reproduction (halves heritability!) Facultative
Sexuality (Ursula LeGuin -- Left Hand of
Darkness) Protandry ltgt Protogyny (Social
control) Parthenogenesis (unisexual
species) Possible advantages of sexual
reproduction include two parents can raise
twice as many progeny mix genes with desirable
genes (enhances fitness) reduced sibling
competition heterozygosity biparental origin
of many unisexual species
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Robert Warner
No Sex Change Protogyny
Protandry
Male
Female
Male
Female Male
Female
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Why have males? The biological advantage of a
sex ratio that is unbalanced in favor of females
is readily apparent in a species with a
promiscuous mating system. Since one male could
fertilize several females under such a system,
survival of a number of males equal to the
number of females would be wasteful of food,
home sites, and other requirements for existence.
The contribution of some of the surplus males to
feeding the predators on the population would be
economically advantageous. In other words, the
eating of the less valuable (to the population)
males by predators would tend to reduce the
predator pressure on the more valuable females.
Blair (1960) The Rusty Lizard
W. Frank Blair
Sceloporus olivaceus
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Sex Ratio Proportion of Males Primary,
Secondary, Tertiary, Quaternary Why have
males? Fishers theory equal investment in the
two sexes
Ronald A. Fisher
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Comparison of the Contribution to Future
Generations of Various Families in Case a in
Populations with Different Sex Ratios ____________
__________________________________________________
____ Case a Number of Males Number of
Females __________________________________________
________________________ Initial
population 100 100 Family A 4
0 Family C 2 2 Subsequent
population (sum) 106 102 CA 4/106
0.03773 CC 2/106 2/102 0.03846 (family C
has a higher reproductive success) _______________
__________________________________________________
_ Note The contribution of family x is
designated Cx.
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Comparison of the Contribution to Future
Generations of Various Families in Case a in
Populations with Different Sex Ratios ____________
__________________________________________________
____ Case a Number of Males Number of
Females _________________________________________
_________________________ Initial
population 100 100 Family E 0
4 Family C 2 2 Subsequent
population (sum) 102 106 CE 4/106
0.03773 CC 2/106 2/102 0.03846 (family C
has a higher reproductive success) ______________
__________________________________________________
__ Note The contribution of family x is
designated Cx.
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Comparison of the Contribution to Future
Generations of Various Families in Case a in
Populations with Different Sex Ratios ____________
__________________________________________________
____ Case a Number of Males Number of
Females _________________________________________
_________________________ Initial
population 100 100 Family A 4
0 Family C 2 2 Family E
0 4 Subsequent population
(sum) 106 106 CA 4/106 0.03773 CC
2/106 2/106 0.03773 All three families have
equal success CE 4/106 0.03773 _____________
__________________________________________________
___ Note The contribution of family x is
designated Cx.
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__________________________________________________
_________________________ Case b Number of
Males Number of Females _________________________
__________________________________________________
_ Initial population 100 100 Family A
2 0 Family B 1
2 Subsequent population (sum) 103 102 CA
2/103 0.01942 CB 1/103 2/102 0.02932
(family B is more successful) Initial
population 100 100 Family B 1
2 Family C 0 4 Subsequent
population (sum) 101 106 CB 1/101 2/106
0.02877 CC 4/106 0.03773 (family C is more
successful than family B) Natural selection will
favor families with an excess of females until
the population reaches its equilibrium sex ratio
(below). Initial population 100 200 Family
B 1 2 Family C 0
4 Subsequent population (sum) 101 206 C
B 1/101 2/206 0.001971 CC 4/206
0.01942 (family B now has the advantage) _________
__________________________________________________
__________________ Note The contribution of
family x is designated Cx.
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Differential Mortality of the sexes during the
period of parental care.
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Differential Mortality of the sexes during the
period of parental care