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Exam Study Guide Ecology Test 3 Flashcards

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Ecology Flashcards for Test 3

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populations of populations

c (colonization rate)

depends on dispersal, migration rate, and interpatch distance

e (extinction rate)

depends on patch size, population size, and heterogeneity within a habitat patch

significance to conservation (metapopulations)

appreciating this aspect of populations revolutionized the way in which conservation biologists managed protected species

Furbish's Lousewort (Pedicularis furbishiae)

threatened plant through need for flooding events and rate of colonization, saved through metapopulations and dispersal among habitat patches

comparison of theoretical and real populations

In the traditional (theoretical) metapopulation, local populations occur in habitat patches within a featureless or homogeneous matrix. Patches are not occupied, and local populations die and come back as extinction and colonization occur.

Landscape Ecology

the study of large-scale environmental heterogeneity, including human alterations to the landscape, on ecological processes

effects on dispersal

some species are better able to disperse through certain matrices better than others

edge effects

effects of boundaries between different habitats on populations within habitat patches (ex. brood parasitism of songbirds by cowbirds)

conductivity of ecosystem processes

roads and the lack of fire conductivity, fragmented landscapes, 


occurs when individuals with certain heritable traits consistently leave more offspring than individuals with other heritable traits

natural selection

heritable traits causing greater fitness in a particular environment

sexual selection

heritable traits causing an advantage to mating and mate choice

direct/directional selection

occurs when one extreme phenotype is favored over all others

stabilizing selection

occurs when the intermediate phenotype is favored over the extremes (can make all phenotypes fall toward the average as time progresses)

disruptive selection

occurs when the environment favors both opposite extreme phenotypes over the intermediate phenotypes

genetic drift

random changes in allele frequencies, a sampling effect that can result from founder effects, bottlenecks, and demographic stochasticity

genetic drift following a founder effect

some alleles by chance are more frequent in a small founding population than in a larger parent population

genetic drift following a population bottleneck

some alleles by chance are more or less frequent in a population that has decreased dramatically in size compared to the original population

gene flow

the exchange of alleles between populations usually associated with sexual reproduction or migration


change in allele frequency due to changes in nucleotide sequences

adaptive (Aptation)

used to describe a physiological, developmental, behavioral, or morphological feature of an organism that enables the organism to perform well in a given environment


process of genetic change of a population whereby a population becomes better suited to its environment the mean fitness of the population increases due to selection


an adaptive trait that was built by the most recent selective environment


modified and derived from an ancestral conditions


an adaptive trait that arose under a different selective environment in the past (may have served a different function in the past)

adaptationist reasoning

assumes that b/c a trait is adaptive, it is likely an adaptation or an exaptation built by natural selection


conservation of traits different species with different phenotypes inherited these phenotypes unchanged from the ancestors (conserved or plesiomorphic)

divergent evolution

related species evolve dissimilar phenotypes upon adaptation to different environment (selective environmental variation and directional selection favors diversification)

convergent evolution

unrelated species evolve similar phenotypes upon adaptation to similar environments (bats and birds with flight)

taxonomic species

a group of populations that differs significantly in appearance or lifestyle from another group of populations

biological speciation

occurs when two populations diverge (genetically) to the point that mating between individuals of the two populations can no longer produce viable offspring

Genotype by Environment Interaction for Fitness of the Origin of Ecotypes

when different genotypes are adapted to different environments, we call them ecotypes

local adaptation

each ecotypes comes to dominate each population or local environment

reproductive isolation

if local adaptation is at some point associated with reproductive isolation of the ecotypes, then the reduced gene flow between the populations may result in genetic divergence sufficient to call the ecotypes different species

allopatric speciation

reproductive isolation may result from prolonged geographic or geologic separation of the ecotypes

vicariant speciation

a range of a species becomes subdivided and these subdivision form new species, all of which may be more or less adapted to the same environmental conditions

geographic speciation

occurs when geographically isolated small populations form new species primarily as a result of genetic drift

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