Bcor 102 Final

Front 1

Population

Back 1

a group of individuals, all of the same species, that live in the same place and have the potential to reproduce with one another

Front 2

Paradigm

Back 2

a view of nature that implicitly defines legitimate problems, methods

Front 3

Tragedy of the Commons

Back 3

the problem of short term versus long-term profits in the exploitation of natural resources.

Front 4

Iteroparous

Back 4

organisms that reproduce at more than one age in their life history. The fecundity schedule for an iteroparous organism would contain two or more non-zero entries for the reproductive ages.

Front 5

environmental stochasticity

Back 5

Uncertainty due to variation in environmental conditions. In an exponential growth model, represented by r, the instantaneous rate of increase. With environmental schochasticity, a pop. is at risk of extinction if variation in r is too large compared to the mean of r. A pop. is never at risk of extinction in the deterministic model of exp. growth as long as r > zero.

Front 6

net reproductive rate (R0)

Back 6

mean # of female offspring produced by a female over her lifetime

Front 7

finite rate of increase (λ)

Back 7

A ratio measuring the proportional change in population size from one time step to the next in a discrete model of exponential population growth. In a population that is increasing exponentially, λ = Nt+1/Nt

Front 8

semelparous

Back 8

a.k.a “big bang” reproduction is a life history strategy which all reproduction is concentrated in a single age. The fecundity schedule for a semelparous organism would have zeroes for all ages except the single reproductive age.

Front 9

demographic stochasticity

Back 9

Uncertainty due to variation in the sequence of births and deaths in a population b/c allele frequencies in a population vary by chance. In small populations, there is a high risk of extinction

Front 10

density dependence

Back 10

A model where b and d are influenced by the size of the population, and overpopulation leads to reduction in births and an increase in deaths

Front 11

Senescence

Back 11

the accumulation of deleterious effects in old individuals. Selection pressure is weaker on older individuals in part because of their lower reproductive value.

Front 12

phenotypic plasticity

Back 12

environmental effects on phenotype

Front 13

periodical cicada

Back 13

insect that waits 13 or 17 yrs to emerge from
underground in extremely large quantities, to reproduce, using the escape in numbers method

Front 14

keystone predator

Back 14

it specializes on a competitively dominant prey species, thereby increasing prey species richness

Front 15

sink population

Back 15

populations for which the local birth rate < the local death rate and the immigration rate > 0

Front 16

keystone species

Back 16

a species whose presence has a major effect on community structure

Front 17

facilitation model

Back 17

model of succession in which each group of species that enters a patch alters the environment in a way that facilitates the entry of successive sets of species

Front 18

pleiotropy

Back 18

single gene affects more than one trait (problem with Mendelian Genetics)

Front 19

Type I Surivorship Curve

Back 19

survivorship high for young individuals and relatively low for old individuals

Front 20

Darlington’s Rule

Back 20

every 10fold increase in island size = doubling of species

Front 21

Modern Synthesis

Back 21

1. Evolutionary phenomena (allelic change, adaptation, speciation) can be explained by mechanisms that are consistent with genetics
2. Evolution is gradual – small genetic changes accumulate, species diverge
3. selection is strongest evolutionary mechanism (+ with drift)
4. allelic frequencies reflect past and current selection
5. micro-evolutionary processes => macro-evolutionary change

Front 22

pre-zygotic isolation mechanisms

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seasonal, habitat isolation, behavioral, mechanical

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Sister species

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2 species sharing a most recent common ancestor

Front 24

Bateman’s principle

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sexual selection should be strongest on males who are competing for females. Offspring production should be more closely related to # of matings in males than females

Front 25

Sexual selection

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selection for traits that maximize reproductive success

Front 26

Sex

Back 26

recombination of alleles with those of another individual via meiosis and fertilization

Front 27

Muller’s ratchet

Back 27

accumulation of deleterious alleles fully expressed in an asexual lineage

Front 28

Kin selection

Back 28

selection favors the spread of allele copies in related individuals

Front 29

Runaway sexual selection

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female choice leads to extreme traits in males that may not have fitness benefits

Front 30

Altruism

Back 30

behavior that increases fitness of another individual but reduces your own

Front 31

Eusociality

Back 31

(ex. Termites, some hymenoptera, naked mole rat)
1. Cooperative Care of young
2. Overlap of at least 2 generations
3. reproductive division of labor (castes)

haplodiploidy
Since females share more alleles with sisters, only one queen gives birth
subterranean nesting, cooperation more energy efficient
sister-sister r = ¾ mother daughter r = ½

Front 32

Female / Male differences

Back 32

the fundamental difference is that disruptive selection on gamete size lead to a state where the female gamete is much larger than the male gamete. This leads to differences in reproductive strategy. Males maximize the number of matings (quantity) and females maximize quantity of mates (high cost for “mistake”) Males have tended to developed different traits: 1. large body size 2. morphological structures for fighting 3. structures for sperm competition 4. copulatory plug 5. alternative mating strategies

Front 33

Peripheral Isolator speciation

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widespread taxon + pre-existing barrier, occasional dispersal over barrier, differentiation and speciation before additional dispersal. Founder effect (= drift)

Front 34

Disruptive selection

Back 34

selection where trait values farthest from the mean have the highest fitness, mean remains the same while variance increases