Conservation Bio 3800 Test #3

Front 1

Demographic Stochasticity

Back 1

principle that if a population contains relatively few individuals, chance variations in the sex ratio of offspring or the survival and reproductive success of individuals can prevail over what is expected on average.

net effect: the rate of population growth will vary from year to year.

Front 2

Environmental Stochasticity

Back 2

refers to fluctuations over time in environmental conditions that affect reproduction or survival of individuals.

Front 3

Allee Effect

Back 3

the positive correlation between population size and individual success.

Figure 7.3 queen conch

Figure 7.4 red hot poker plants

Front 4

Genetic Drift

Back 4

evolutionary process of random changes in gene frequencies

Front 5

Genetic Rescue

Back 5

improved population fitness that results from interbreeding with immigrant individuals

Front 6

Effective Population Size

Back 6

Ne = effective population size

Ht = heterozygosity after t generations

Ho = original heterozygosity

Heterozygosity is lost more quickly in populations with smaller Ne

The more generations a population remains at a small Ne the more genetic diversity it will lose.

Front 7

Gene Flow

Back 7

the exchange of alleles among populations resulting from the movement and cross-mating if individuals from distinct populations.

Front 8

Why does allelic diversity tend to decline in small, isolated populations?

Back 8

combination of genetic drift and limited gene flow.

Front 9

Why is an individual whose parents are closely related likely to suffer reduced fitness?

Back 9

inbreeding increases homozygosity which can be a disadvantage relative to heterozygosity.

inbreeding increases the chance that an individual will carry two copies of a rare harmful recessive allele

Front 10

which is an assumption of an ideal population?

Back 10

even sex ratios

Front 11

Relationship between effective population size and variance in offspring production.

Back 11

Ne can equal the raw count of individuals

Ne=N

Front 12

Fig 7.4 The figure below shows that red hot poker plants planted in small groups (with few other red hot poker individuals) did not produce as many seeds per plant compared to individuals planted in large patches.

Back 12

the fitness of an individual plant was positively related to patch size, but only when birds were able to access them. This is evidence of the Allee Effect, because birds are less likely to visit and pollinate flowers that exist in small patches.

Front 13

Ideal Population

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assumes the number of individuals is constant, all individuals are breeding adults, and the numbers of males and females are equal.

Front 14

Relative abundance

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the number of individuals spotted or trapped per unit of effort estimates___________.

Front 15

Quadrats

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small rectangular plots of land where researchers can record the density of individuals.

Front 16

If you used a Lincoln–Petersen mark-recapture approach to estimate the size of an animal population, but the tags were defective and fell off some percentage of the originally sampled individuals, the method would tend to

Back 16

overestimate population

r/s would be reduced

r = recaptured

s = individuals sampled

m = marked individuals

Front 17

If you used a Lincoln–Petersen mark-recapture approach to estimate the size of an animal population, but the tags were attractive to predators, the method would tend to

Back 17

overestimate population

underestimate r

inflate N

Front 18

If you used a Lincoln–Petersen mark-recapture approach to estimate the size of an animal population, but tagging individuals affected their probability of recapture, the method would tend to

Back 18

if tag decreased probability of recapture you would overestimate population

if tag increased probability of recapture you would underestimate population

Front 19

Using a species' current level of genetic diversity to estimate its historic population size requires data, or at least a range of assumptions about

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rate of mutations

current Ne

species generation time

Front 20

The 30-year-long effort in India to census the nation’s tiger population could have been improved by

Back 20

tracking time spent searching for pugmarks

tracking locations of pugmarks as they were found

Front 21

This simple model of exponential population change,

Nt + 1 = λNt, assumes

Back 21

constant environmental conditions

unlimited resources

identical probabilities of survival and reproduction for all individuals

Front 22

To perform even the most basic population viability analysis requires all of the following

Back 22

population growth rate

starting population size

variability in population growth rate

Front 23

PVA (Population Viability Analysis)

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used to estimate

the probability of extinction within a time

expected average population size at some time

the range of population sizes that is likely at some specified time (95% CI)

Front 24

Loci

Back 24

stretches of DNA that do not code for proteins or RNA

Front 25

Population Growth Rate

∂ = Nt+1/Nt

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the realized rate of change is the geometric mean ∂

ie: √.09 x 1.2 x .08 = .952

[1-.95 = .5] or 5% decline or change

Front 26

Demographic Matrix Model

Back 26

models that better reflect the real world

uses age, stage or size as the probabilities of birth and death

Front 27

Population Growth Rate Model

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unrealistic assumptions:

density independent population change (+or- growth at constant rate)

deterministic population dynamics (no environmental stochasticity, (good/bad years)

homogenous individuals (same reproductive success)

closed population (no movement in or out of population other then birth and death)

Front 28

Habitat Fragmentation

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can lead to:

edge effects

metapopulation dynamics

faunal relaxation

Front 29

The rate of colonization increases as...

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distance from mainland decreases

Front 30

The rate of extinction increases as...

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# of species grows

Front 31

what does this graph mean?

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larger parks have experienced fewer mammal extinction since established

Front 32

SLOSS

Single Large Or Several Small

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different size reserves could harbor a greater # of species, depending on the degree of species nestedness

Front 33

High degree of nestedness

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one large reserve harbors more species

Front 34

Low degree of nestedness

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several small reserves harbor more species

Front 35

The theory of island biogeography

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makes it clear that a single large habitat will, on average, sustain more species than a single small habitat

Front 36

nestedness

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increases with species overlap (high degree)

Front 37

according to this figure:

Back 37

isabella harbors fewer native land bird species than all the other G. islands combined, despite the fact that isabella is larger than the cumulative area of the other islands

Front 38

according to this figure:

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colonization is highest when half of the habitat patches are occupied

extinction increases linearly with patch occupancy

extinction is equal to the rate of colonization at two points (f* and f=0)

Front 39

Dispersal Corridors can benefit by what?

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facilitating recolonization of an area following local extirpation

facilitating gene flow that can alleviate inbreeding depression

Front 40

Inbreeding Depression

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a reduction in the survival or reproductive fitness of offspring produced through inbreeding

Front 41

Negative consequences to dispersal corridors

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ecological traps

disrupt evolutionary divergence

facilitate movement of non-native species among patches

Front 42

Inbreeding coefficient (Fst)

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can be used to measure the degree of isolation of subpopulations

a high Fst indicates a dispersal corridor may be a good investment because migration between subpopulations is currently limited

Front 43

Edge effects

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differences in both environmental and biotic conditions between the edges and the interiors of habitat patches

Front 44

Faunal relaxation

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shrinking of number of species

Front 45

habitat matrix

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area surrounding the protected one

Front 46

Buffers

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overcome the edge effects

Front 47

metapopulations

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a collection of spatially isolated subpopulations of the same species that interact at some level

Front 48

The equilibrium theory of island biogeography

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equilibrium number of species on a large, less isolated island is greater than the equilibrium number of species on a small, more isolated island.

(based on colonization/extinction rate)