Ecology Test #2

Front 1

Individual

Back 1

That's you

Front 2

Population

Back 2

Group of individuals of a single species inhabiting a specific area

Front 3

Species

Back 3

a group of populations whos individuals have the potential to interbreed and produce fertile offspring

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Important points of natrual selection

Back 4

Individuals vary
Some variation is heritable
More individuals produced than will survive
Different survival to reproduction

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Common Garden Experiment

Back 5

To exemplify the fact that phenotypic variation reflects genes and environment

Front 6

All environment, no genetic

Back 6

All would grow to same height, and that height would depend on elevation

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All genetic, no environment

Back 7

Each plant would grow to the same size no matter where it was located

Front 8

Both genetic and environment

Back 8

Plants would retain same ratio, they would all be bigger in the middle garden, slightly smaller in bottom garden, and even smaller in top garden

Front 9

More individuals produced than can survive

Back 9

Elephant reproduction - Female reproduces at age 30,
1 calf every 10 years until age 90
1 pair + 500 years = 15 million elefantes

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Natural Selection -

Back 10

Beatles - the white ones get picked off, the survivors reproduce and pass the traits to their offspring

Front 11

Moths and natural selection -

Back 11

Before industrial revolution - 10% dark
After industrial revolution - 80% dark

Front 12

Microevolution -

Back 12

changes in allel frequency in a population over time.

Front 13

Macroevolution -

Back 13

"Long-term" changes like splitting of one species into two or the origin of new taxonomic groups.

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Allel frequency

Back 14

The relative proportion of an allele for a locus in the gene pool

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Gene pool

Back 15

all of the alleles in a population

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Hardy-Weinberg theorem -

Back 16

For all frequencies to remain constant -

No mutation
No genetic drift
No gene flow
No selection
Random mating

If these conditions are not met - evolution can happen.

Front 17

Mutation -

Back 17

new alleles form because of random changes in DNA

Front 18

Genetic Drift -

Back 18

by chance, only certain members of population reproduce (founder effect, bottleneck effect)

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Mutation occurs ______

Back 19

frequently in small populations

Front 20

Gene flow -

Back 20

movement of alleles between populations
tends to reduce differences between populations

Front 21

Non-random mating

Back 21

individuals often choose a mate according to phenotype

Front 22

Assortative mating -

Back 22

Individuals select mates that are like themselves

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Choosey females -

Back 23

males chosen based on phenotype
may lead to sexual dimorphism

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Selection -

Back 24

Natural, artificial, sexual

Front 25

spontaneous mutation

Back 25

generates new alleles
overall rates are low 1:100,000 but important
must occur in cells that become gametes

Front 26

Sexual Reproduction

Back 26

crossing over
independent assortment
random fertilization

Front 27

Forms of Natural Selection

Back 27

Directional
Disruptive
Stabilizing

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Directional Selection -

Back 28

One extreme is favored
Most common during periods of environmental change or when individuals migrate to new habitat

Ex. Pepper moth (color) Galapagos finches (beak shape)

Front 29

Disruptive selection -

Back 29

Eliminates the intermediate phenotype; favors extremes.
Not very common.

Front 30

Stabilizing selection

Back 30

intermediate phenotype is favored
selection against extreme phenotypes
ex. human infant birth weight (2-10.8 pounds)
Death rate is high at extremes of range

Front 31

Population -

Back 31

group of individuals of a single species inhabiting a specific area.

Characterized by the number of individuals and their density.

Front 32

Population Ecology -

Back 32

Spatial distribution and abundance

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Population structure

Back 33

Densities, spacing, age classes, genetic variation

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Populations are groups of ____

Back 34

Individuals

Front 35

Unitary -

Back 35

Bison, Lemur, Emu

Front 36

Modular -

Back 36

Flowering Plant
Anemone

Front 37

Distribution

Back 37

The natural geographic range of an organism OR the spatial arrangement of individuals in a local population

Front 38

Environmental constraints determine in part the _____

Back 38

geographic range
Also
Habitat
Dispersal
Climate and other abiotic factors

Front 39

Dispersal

Back 39

Spread, reproduction, new habitat

Front 40

At large scales -

Back 40

physical environment limits geographic distribution of species

Front 41

Diagram of dispersal -

Back 41

Dispersal -> climate -> Habitat -> Location

Front 42

Example of Distribution

Back 42

Tiger Beetle
Same optimum temperatures despite wide sdispersal?
Yes. Same opt. Temp. in Maine, Colorado, Arizona, Wisconsin

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Ideal Free distribution -

Back 43

Individuals should choose among patches to maximize fitness

Front 44

Desert Shrubs -

Back 44

From clumps to regular even spacing

Front 45

Abundance -

Back 45

# of Individuals

Front 46

Density -

Back 46

# of Ind/Area

Front 47

Population density and Organism size

Back 47

Population density up
Organism size down

Front 48

Metapopulation -

Back 48

Made up of a group of subpopulations living on patches of habigtat connected by an exchange of individuals

Front 49

Are big patches normal?

Back 49

No

Front 50

Formula for dynamics and growth -

Back 50

Nnow = Nthen +Birth - Death + Immigration - emmigration

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Period -

Back 51

Up and down

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Fecundity -

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Reproductive Capacity

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Cohort -

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Things that don't move

Front 54

Survivorship -

Back 54

Graph 1 - High for a while then dropping off at right - mammals
Graph 2 - equal mortality - american robins
Graph 3 - fast at first then levels off - some plants

Front 55

Stable Age distribution -

Back 55

Individuals in age class stays constant

Front 56

Geometrically Growing -

Back 56

Growth isn't constant.
Breeding seasons.
Generations don't overlap

Front 57

R sub o

Back 57

Net reproductive Rate
R<Shrinking
R>Growing
R=1Constant

Front 58

Malthusian Doctrine

Back 58

Starve
Competition for Resources
Diseases
Antagonistic Behavior

Front 59

What is a life history?

Back 59

Represent a balance between survival and reproduction

Front 60

Gene Flow -

Back 60

Population Level
Dispersal
Decreases variation between populations

Front 61

Classification based on Lx, Mx, a

Back 61

lx - juvenile survivorship
Mx - Fecundity
a = age of reproductive Maturity

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Opportunistic -

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Low Lx, Low Mx, Early a

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Equilibrium -

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High Lx, Low Mx, Late a

Front 64

Periodic -

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Low Lx, High Mx, Late a

Front 65

Guild -

Back 65

Organisms that do similar things

Front 66

Life form -

Back 66

Morphology/life history category

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Taxon -

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Taxonomic group Eg. Birds

Front 68

Place/Habitat -

Back 68

Microbes on teeth

Front 69

Logistic Growth -

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Some idealized increase, max per capita growth rate that could happen

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r =

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births - deaths (per capita rate of increase)

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density dependent -

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(1 - n/k ) n = # of individuals
k = carrying capacity

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Rabinowitz -

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1 - Population size (local)
2 - Habitat Tolerance (small or great)
3 - Geographic Range (wide or limited)

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Senessence -

Back 73

physiological decline over time leading to death, non random mortality

Front 74

Example of Ideal Patch Finding -

Back 74

Fish tank feeding experiment
Blue tit populations in oak woodlands (even though they were dying off in the evergreen forests, they kept leaving)

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3 kinds of dispersion -

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Random - equal chance of being anywhere
Resources often distributed uniformly
Frequent, random pattern of disturbance
Regular - Uniformly spaced
Exclusive use of areas (territoriality)
Individuals avoid each other
Clumped - Unequal chance of being anywhere
Mutual attraction between individuals
Patchy resource distribution

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Shrubs -

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Regularly spaced due to competition
Seeds germinate at safe sites
Seeds dont disperse from parent areas
Asexual reproduction

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Population decreases according to -

Back 77

Organism size. Bigger - less dense. Smaller - more dense.

Front 78

Population dynamics includes

Back 78

Birth, death, survivorship
Age distribution
Dispersal
Rates of population change

Front 79

Life History Data -

Back 79

Age of first reproduction
Number of young
Number of reproductive events
Life span
Mortality

Front 80

Life tables -

Back 80

Explore population dynamics in context of
birth
death
survivorship
age distribution

Front 81

Static Life Table -

Back 81

Up and down

Front 82

Cohort -

Back 82

Diagonal

Front 83

Life tables -

Back 83

consist of a series of columns which describe aspects of mortality and reproductive output for members of a population according to age.

Front 84

Life tables used to -

Back 84

Analyze probabilities of survival of individuals in a population
Determine ages most vulnerable to mortality
Predict population growth

Front 85

Cohort Life Table -

Back 85

Identify individuals born at same time and keep records from birth to death (good for plants and sessile organisms)

Front 86

Static life table -

Back 86

Record age at death of individuals within a certain time period (good for mobile and long-lived organisms)

Front 87

Age distribution -

Back 87

Calculate difference in proportion of individuals in succeeding age classes
Assumes differences from mortality
Also produces static life table

Front 88

High survivorship of young -

Back 88

Most mammals and some plants

Front 89

Equal death and birth -

Back 89

Amphibians and some birds

Front 90

Many plants, invertebrates, amphibians, and fish have very _____ survivorship as juveniles

Back 90

low

Front 91

Age distribution reflects -

Back 91

History of survival (high and low periods)
Periods of successful reproduction
Growth Potential

Front 92

Stable age distribution results in -

Back 92

steady growth.

Front 93

The rate of change in the population is _____

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Exponential

Front 94

growth is on a per

Back 94

individual basis

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Generation time -

Back 95

Average time from egg to egg

Front 96

Dispersing and sedentary stages of organisms -

Back 96

Windblown dandelion seeds
Water borne larvae of barnacles
Juvenile spiders disperse by spinning a silken thread that catches the wind

Front 97

Logistic population growth -

Back 97

What happens when resources are depleted and exponential growth slows

Front 98

Carrying Capacity (K) -

Back 98

Number of individuals of a population the environment can support
Finite amount of resources can only support a finite number of individuals

Front 99

Examples of logistic growth -

Back 99

Yeast and Barnacles

Front 100

Key to Logistic Growth -

Back 100

As population density increases, the per capita availability of resources declines

Front 101

Density dependent factors -

Back 101

Influence a population in proportion to its size
Disease
Resource Competition
Predation
Negative Feedback

Front 102

Density Independent factors -

Back 102

Influence a population regardless of population size
Natural disasters (flood, hurricane)
Influence growth rate, but don't regulate population

Front 103

Example of density dependence -

Back 103

Mandarte Island song sparrow

Front 104

Density dependence in plants

Back 104

Sowing density and flax plant size
More seeds smaller plants

Front 105

Self thinning -

Back 105

The progressive decline in density and increase in biomass of remaining individuals

Front 106

Density independence in animals -

Back 106

Finches and drought. No water - no finches. When water came back, finches came back

Front 107

As populations get bigger,

Back 107

Body size decreases

Front 108

Life History Strategies represent -

Back 108

a balance between demands of survival and reproduction

Front 109

Allocate Resources -

Back 109

Fitness - the true measure of an organisms reproductive success is fitness - natural selection favors traits that maximize fitness
Tradeoffs - imposed by constraints of physiology, energetics, and the physical and biotic environment - allocation principle - cost of reproduction

Front 110

Many life history characteristics have to do with reproduction

Back 110

Age at 1st reproduction
Timing of reproduction
offspring size
parent size
offspring number

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Younger rate of reproduction -

Back 111

less chance of surviving to an old age

Front 112

Semelparity -

Back 112

Reproducing only once in a lifetime

Front 113

Iteroparity -

Back 113

Reproducing more than once in a lifetime

Front 114

Large seeds -

Back 114

Faster growth, bigger seedlings
Fewer seedlings, but survive better

Front 115

Small seeds -

Back 115

Advantage in areas of high disturbance

Front 116

Methods of dispersal -

Back 116

Unassisted - no special structure
Adhesion - hooks, spines, or barbs
Wind - wings, hair (resistance structures)
Ant - oil surface coating (elaisome)
Vertebrate - fleshy coating (aril)
Scatterhoarded - gathered, stored in caches

Front 117

In the absence of senesence, individuals die by _____

Back 117

Chance

Front 118

No senesence means -

Back 118

fewer alive at old age
selection favors improved fecundity at young ages
senesence should progress faster in populations with high extrinsic mortality

Front 119

Two most important variables exerting selective pressures on plants -

Back 119

Intensity of disturbance - any process limiting plants by destroying biomass (e.g., grazing, frost, fire)
Intensity of stress - External constraints limiting rate of dry matter produciton (limiting resources such as light and water; temperature stress)

Front 120

Plant life history strategies -

Back 120

Ruderals - highly disturbed habitats - grow rapidly and produce seeds quickly
Stress tolerant (high stress, no disturbance) - grow slowly - conserve resources
Competetive (low disturbance, low stress) - grow well, but eventually compete with others for resources