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19 Cards in this Set

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Natural Selection
assumpations:
-more organisms are born than can survive
-great variation among organisms
-most effective variation will be present in next generation
descent with modification
new forms arise and old one disappear. new forms arise through natural selection
metapopulation model
deals with islands ... small pockets not continuous with larger population and the addition of new alleles is slower.
sexual selection
involves the competition for mating. superimposed on natural selection.
-- sexual dimorphism - one sex is larger and controls the breeding
optimization
organisms become more and more adapted for their environment ... will never be perfect though becuase of too many constraints and the limitation of alleles (only have certain alleles so will not have all alleles needed for perfection)
Speciation
sympatric versus allopatric. speciation can arise from drift/mutation/natural selection/coadaptation
Reproductive isolating mechanisms:
pre-zygotic and post-zygotic. pre are things that keep organisms from breeding (habitat, temporal/behavioral/mechanismal)
-post -> keep offspring from being fertile/surviving ..
hybridization
two diff species give rise to one highly variable species but ... sometimes in F2 generation, the offspring will not be fertile/viable (hybrid breakdown)
character displacement
two organisms are more different when they are together than when they are seperated ... due to competition
sympatric speciation
species in the same area ..
can lead to polyploidy, sexual selection, and change in host imprinting ...
heterochromy
certain genes act as controller genes ... turn on other genes and dictate how long they remain on ... explains how two species can have such similar DNA but look and act so differently ...
Population Growth
associated with natality, mortality, and age structure ... there are many factors that effect the rate of reproduction .. 1)only females get pregnant 2)age of 1st reproduction 3) reproductive period (semelparity vs. iteroparity) and 4) litter size
Population Growth curves
Type 1 .. most live a long time and die off at once
Type 2 .. constant # dying
Type 3 .. constant fraction dying
Type 4 .. many die young and then likely survive if survive
Stable environments ..
in a stable enviroment, the R=1 .. meaning each ind. replaced by one individual (pop not growing or declining)
Exponential Growth
overlapping vs. non-overlapping generations (overlapping generations equation incorporate the log..)
altruistic acts
acts that are for the good of the species ... it can be ewxplained evolutionarily ... you want your genes to be propogated in the next generations so you do things that will help make that happen (ex. bees and turkeys; warning calls)
Continental Drift
Effects:
1)volcanic activity
2)climatic changes
3)mounntain formation(influences wind and climate patterns -> rain shadow)
4)latitudinal position
5)connectedness -> continuous land mass vs. broken up land mass...
6)glaciation - migration still occuring from the last glaciation
Community Delineation
1)would similar communities share similar organisms??
2)continuity - how sharp are the boundaries between communities??
3)distributional overlap
4)history - the effects of glaciation on species recolonization and movement
5)interactions - the more crosslinks withing a community, the more tightly connected a community is .. (ex: spuirrels that eat truffles. pine trees and fungi are dispersed through the squirrel not being able to digest the spores)
Variations in Life Forms
The amounf of solar radiation/temperaure/precipitation effects the variations in life forms. (ex. leaf shape .. smaller leaves have advantage b/c more S.A. per volume .. sun leaves on top of trees are more lobed b/c more surface area