Part 1 (Natural selection) Flashcards
(23 cards)
Certain alleles are favored that increase in frequency, while others are favored and decrease in frequency
Natural selection
What is the effect on variation?
Can maintain/ increase or decrease
The ability of a genotype to leave offspring in the next generation
Fitness
Hardy Weinberg equilibrium is a
null hypothesis
Specifies what should be observed
Null hypothesis
Random changes in allele frequency; most important in small populations
Genetic Drift
the effect of genetic variation? (genetic drift)
reduce
The effect on average fitness? (genetic drift)
reduce
-Variation exists among individuals in population
-Traits are heritable
-Survival and reproduction are highly variable
-Non-random survival and reproduction
Darwins Postulates
Random production of alleles
mutation
What increases genetic variation?
mutation
-Frequencies drift up and down over time
-especially affects small populations
Genetic drift
-adding new alleles (evolution)
-removing alleles (evolution)
Gene flow
High gene flow =
more similar populations
Low gene flow =
more different populations
Movement of alleles between population; reduces the differences between populations
gene flow
Change in nucleotide base
random production of new alleles
mutation
-Genetic variation is reduced
-no change in average value of trait over time
Stabilizing
change in one direction
directional
-Genetic variation is increased
-favors extreme phenotype
Disruptive
change average value of a trait
directional selection
increases variation in a trait
disruptive selection
