Exam 1 Flashcards
when was Hardy-Weinberg equilibrium discovered?
1908
what is the basis of the Hardy-Weinberg equilibrium?
allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences
Hardy-Weinberg is known as evolution’s ___________
null hypothesis
how do we know/determine if a population is at equilibrium?
- determine the gene frequency in the current generation and determine the expected gene frequency for the next generation
- if in equilibrium, there should be no change between the two generations
measures of genotype can predict __________
allele frequencies
measures of allele frequencies can predict _________
genotype
combined probability that two independent events will occur together is equal to the ______ of their probabilities
product
combined probability of two mutually exclusive events will occur is the ________ of their probabilities
sum
getting EITHER heads or tails on a dime is an example of what type of event? how would you calculate this probability?
- mutually exclusive event
- 1/2 + 1/2 = 1
getting heads on a dime and heads on a penny is an example of what type of event? how would you calculate this probability?
- two independent events
- 1/2 x 1/2 = 1/4
what are the 2 conclusions of HW?
- given HW, the allele frequencies in a population will not change, generation after generation.
- given HW, if the allele frequencies are p and q, then the genotype frequencies will be p^2, 2pq and q^2
For HW to occur, there cannot be…
genetic drift, selection, migration or mutation
T / F : genetic drift does not depend on population size
F
populations losing alleles by chance is an example of
genetic drift
__________ is often referred as evolution due to “blind luck”
genetic drift
T / F : genetic drift’s influence is equally strong in smaller and larger populations
F, stronger in smaller sizes
what is the founder effect?
the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population
what is fitness?
the success of an organism at surviving and reproducing and thus contributing offspring to future generations
define migration
movement of alleles between populations
if some genotypes survive and reproduce at higher rates than others….
allele frequencies will change over time
can migration change allele frequencies?
yes!
can migration produce genotype frequencies that are not consistent with HW?
yes!
what is an example of migration counteracting selection that we talked about?
allele for banded pattern in snakes is not selected out of island populations even though un-banded pattern is more advantageous to the island snakes
migration can prevent ________
divergence