UF BSC 2010 EXAM 3 REVIEW QUESTIONS AND
100% CORRECT ANSWERS
parsimony principle
1.) simplest explanation
2.) tree with the fewest character transition
3.) fewest homoplasies
artificial selection
1.) breeding for desirable traits
2.) humans determine an organisms fitness through selective breeding
natural selection
1.) differential reproductive success of certain individuals with more or less desirable traits
2.) acts on heritable variation in a way that favors the traits that lead to reproductive fitness and
promotes adaptive evolution
3.) only acts on existing variation
4.) DOES NOT act on genotypes, favor the perfect phenotype, or create genetic variation
heritable
can be passed from parent to offspring
differential reproductive success (DRS)
individuals with more desirable traits will be more likely to pass those traits to future generations
evolution
changes in biological populations (NOT individuals) over time
3 things necessary for natural selection to occur
1.) Variation in the trait
2.) Heritability
3.) Impact on reproductive success
gene pool
sum of all of the alleles for a particular locus in a population
adaptation
1.) beneficial mutation favored by natural selection
2.) refers to both the favored trait and the process by which the trait emerges in the population
mutation
, change in the nucleotide sequence (random)
2 sources of phenotypic variation
V(g) - genetic variation
V(e) = environmental variation
V(p) = V(g) + V(e)
heritability
1.) (h^2) = V(g)/V(p)
2.) Fraction of variability NOT fraction of trait that is genetic
parent-offspring regression line
relates traits of offspring to biological parents
ex: slope 0f 0.5 -> 1/2 of the variability is due to the parents
Breeder's equation
1.) quantify response to natural selection in terms of heritability and selection differential (S)
2.) R = (h^2)(S)
selection differential (S)
measure of the intensity of selection on a particular trait
fitness
genotype and phenotype's contribution to the genetic composition of future generations; which
organisms are more likely to survive AND reproduce
Directional selection
one extreme phenotype is the fittest
mean changes, variance does not
ex: TX longhorns
Stabilizing selection
1.) aka purifying selection
2.) stabilize around intermediate trait as genetic variation decreases
3.) Fitness is highest at average phenotype
4) mean doesnt change, variance changes
ex: human birth weight
Disruptive selection
1.) trait tends toward BOTH extremes
2.) Causes the emergence of two species
3.) bimodal distribution leads to eventual sympatric speciation
100% CORRECT ANSWERS
parsimony principle
1.) simplest explanation
2.) tree with the fewest character transition
3.) fewest homoplasies
artificial selection
1.) breeding for desirable traits
2.) humans determine an organisms fitness through selective breeding
natural selection
1.) differential reproductive success of certain individuals with more or less desirable traits
2.) acts on heritable variation in a way that favors the traits that lead to reproductive fitness and
promotes adaptive evolution
3.) only acts on existing variation
4.) DOES NOT act on genotypes, favor the perfect phenotype, or create genetic variation
heritable
can be passed from parent to offspring
differential reproductive success (DRS)
individuals with more desirable traits will be more likely to pass those traits to future generations
evolution
changes in biological populations (NOT individuals) over time
3 things necessary for natural selection to occur
1.) Variation in the trait
2.) Heritability
3.) Impact on reproductive success
gene pool
sum of all of the alleles for a particular locus in a population
adaptation
1.) beneficial mutation favored by natural selection
2.) refers to both the favored trait and the process by which the trait emerges in the population
mutation
, change in the nucleotide sequence (random)
2 sources of phenotypic variation
V(g) - genetic variation
V(e) = environmental variation
V(p) = V(g) + V(e)
heritability
1.) (h^2) = V(g)/V(p)
2.) Fraction of variability NOT fraction of trait that is genetic
parent-offspring regression line
relates traits of offspring to biological parents
ex: slope 0f 0.5 -> 1/2 of the variability is due to the parents
Breeder's equation
1.) quantify response to natural selection in terms of heritability and selection differential (S)
2.) R = (h^2)(S)
selection differential (S)
measure of the intensity of selection on a particular trait
fitness
genotype and phenotype's contribution to the genetic composition of future generations; which
organisms are more likely to survive AND reproduce
Directional selection
one extreme phenotype is the fittest
mean changes, variance does not
ex: TX longhorns
Stabilizing selection
1.) aka purifying selection
2.) stabilize around intermediate trait as genetic variation decreases
3.) Fitness is highest at average phenotype
4) mean doesnt change, variance changes
ex: human birth weight
Disruptive selection
1.) trait tends toward BOTH extremes
2.) Causes the emergence of two species
3.) bimodal distribution leads to eventual sympatric speciation
