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33 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Phenotype
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Physical characteristic
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Genotype
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Genetic makeup, give phenotype
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Natural Selection
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Success in the reproduction of different physical characteristics.
Results from the interaction of organisms with their environment |
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Artificial Selection
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By controlling survival and reproduction, dramatic change occurs in a short period of time
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Stabilizing Selection
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Average population stabilizes on a particular trait. Extreme value is selected against
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Alligator example on wikipedia
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Directional Selection
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One extreme is favored
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Allele frequency shifts in one DIRECTION
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Diversifying (disruptive) Selection
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Extreme characteristics/phenotypes favored
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Light and dark moths
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Neutral Variation
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Differences in genes that aren't involved in evolutionary changes
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Fingertips
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Microevolution
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Generation to generation change sin a population's gene pool
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What are the 4 causes of microevolution?
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Natural selection, genetic drift, gene flow and mutation
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Natural Selection acts on ________
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Phenotypes!
(what acts on phenotypes?) |
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Evolutionary change requires change in __________
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Genotypes!
(______ ______ requires change in genotypes) |
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Heritable traits
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Traits with genetic basis
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Alleles
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Variations /alternative forms of any gene
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Mutation
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change in structure of a gene or chromosome
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Genetic Drift
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Changes in the gene pool of a small population due to chance.
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2 cases = bottleneck effect and founders effect
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Bottleneck effect
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When population size decreases and consequently does so genetic diversity.
Mating of survivors, keeps diversity low. Lots of alleles lost |
Like emptying a bottle full of different colored beads.
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Founder's effect
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Occurs when a few individuals colonize a new area. Increase in rare allels
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Like bottleneck, but not b/c of drop in population size, rather colonization.
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Gene Flow
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The exchange of genes between populations. Reduces differences between populations
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Three things that influence the Genetic Variability on which selection acts
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1. Mutation
2. Gene flow 3. Genetic Drift |
M.G.G
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Alloatric
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The ranges of two populations or species that DO NOT overlap
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Sympatic
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Ranges of two populations or species that DO overlap
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Adaptive Radiation
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Many species derived from a common ancestor introduced to new environments
(genetic drift and natural selection) |
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Reproductive isolating mechanisms
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Prevent mating between species
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Extrinsic
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Geographical isolation (allopatry)
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Intrinsic
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Determined by the genetic makeup of the individual
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INside
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Temporal Isolation
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Timing is different for breeding between species
Pre-zygotic reproductive barrier |
TEMPS = francais pour TIME
Pre-zygotic barrier |
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Habitat Isolation
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Location for breeding is different between potential species
Pre-zygotic reproductive barrier |
Pre-zygotic reproductive barrier!
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Behavioral Isolation
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Behavior for attracting mates is different
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Pre-zygotic barrier
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Mechanical isolation
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Doesn't work! "lock and key" common for insects
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Gametic isolation
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The sex organs/cells aren't compatible
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Key work: GAMETE
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Reduced Hybrid Viability
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Fertilization occurs but offspring frail/do not complete development. Or no offspring of one sex.
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Reduced Hybrid Fertility
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Fertilization occurs but offspring cannot reproduce
Ex Mules and Ligers |
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