Define Mutation
What is any permanent change in the hereditary material of an organism/ the ultimate source of new alleles?
Phenotype results from these two conditions
What is environment and genotype?
This is the formula used to calculate heritability
1) This type of selection acts to favor a phenotype/ genotype
2) This type of selection acts to eliminate a phenotype of genotype
What are...
1) positive selection
2) negative selection
This form of variation influences gene expression, but not genotype itself
What is Ve/ environmental effects?
Define Pleiotropy
What is a single gene that affects many traits?
How would you arrange a dihybrid cross with the F1 female genotype being RrYy and the F1 male genotype being RrYy?
What are...
female: RY, Ry, rY, ry
male: RY, Ry, rY, ry
These are the formulas that determine a population is NOT evolving.
What is Hardy Weinberg?
1=p^2+2pq+q^2
p+q=1
This is the type of selection that selects for the extremes of a trait and selects against the average phenotype
What is Disruptive Selection?
This action produces different combinations of chromosomes in gametes
What is independent assortment?
Define Co-dominance
What is both alleles are expressed and the heterozygote manifests a third phenotype that is an intermediate (both properties) of both alleles?
Natural selection acts ONLY on this type of variation.
What is genotypic variation
In a given population, the heritability (h^2=0). This means...
True or False
Selection can act on a population that has a heritability of 0.
What is false?
h^2=1 indicates this
What is all phenotypic variation in a population is due to genotypic variation- there is complete inheritance?
Define Epistasis
What is the phenotype associated with an allele depends on which alleles of another gene are present?
In a given population, these are conditions that would lead to Vp being the highest.
What is large genotypic variation and environmental effects that influence phenotype expression?
In a population of 500 birds, two alleles control feather color: a dominant allele (B) and a recessive allele (b). The frequency of the recessive allele (b) is 0.3. Assuming the population is in Hardy-Weinberg equilibrium, calculate the frequency of the heterozygous genotype
What is 2pq= 0.42
These two selective forces maintain genetic variation in a population
What are heterozygote advantage and frequency-dependent selection?
These are the characteristics of a population that is NOT evolving (5)
What are...
1) No mutations
2) No natural selection
3) Large population size (no genetic drift)
4) No gene flow
5) Random mating (all individuals have an equal probability of passing on their alleles)
Define Selection Differential (S)
formula: S=P*-P
P*=population trait mean after event
P=population trait mean before the event
BONUS: What does this tell us?
What is a mathematical way to quantify shifts in the mean phenotype of a population before and after a selection event?
BONUS: This tells us how strong the selective pressure is
BACKGROUND: male was round, female was wrinkled
1) Organisms have 2 copies of each gene
2) Genes are passed from parent to offspring and do not change in the process (particulate inheritance)
3) Gametes contain one allele (principle of segregation)
4) Females and males contribute equally to offspring (one allele from each parent)
5) Some alleles are dominant to other alleles.
In a population of 1,000 frogs, there are two alleles for skin color: a dominant allele (A) and a recessive allele (a). 36% of the frogs display the recessive phenotype (aa).
Assuming the population is in Hardy-Weinberg equilibrium, calculate the frequency of the dominant allele (A) and the recessive allele (a).
What are...
F(A)= 0.6
F(a)=0.4
These are the requirements that must be met in order to predict that a population has evolved by natural selection.
What are...
1) Variation present in the population for a given phenotypic characteristic
2) Selective pressure present
3) Differential survival/ reproduction (in response to the selective pressure)
4) The characteristic must be heritable
5) Alleles for the adaptive phenotype are more prevalent in the next generation
A population of stingrays has acquired a mutation. This mutation has an inherent tendency to result in an adaptive trait
What is false?