lecture 1: evolutionary forces

Question 1

evolution

Answer 1

a change in the genetic composition of a population across generations; measured by a change in the allele frequency of a population across generations

Question 2

evolutionary forces

Answer 2

factors that cause allele frequencies to change; ex. mutation, natural selection,
genetic drift, gene flow

Question 3

mutation

Answer 3

a change in the genetic sequence of an organism; the only source of new genetic variation; can be beneficial, neutral, or harmful depending on the environment; occurs randomly & is unconnected to an organism’s needs

Question 4

recombination (mutation)

Answer 4

recombination during meiotic cell division shuffles existing genetic variation to create new combinations

Question 5

adaptation (natural selection)

Answer 5

matches an organism to its environment; the process of adaptation: the process by which useful characteristics evolve by natural selection; an adaptation: characteristic that makes it more likely for an organism to survive & reproduce

Question 6

criteria for artificial or natural selection

Answer 6

1. variation for a trait which has to lead to
2. differential survival or reproductive success (fitness) depending on trait value
3. transmission of trait value to next generation (trait variation must be heritable)
   
   • if all these criteria are met, then you can have a change in allele frequencies, such that a higher proportion of the population has the fitter trait value

Question 7

how natural selection works

Answer 7

1. mutation creates variation
2. unfavorable mutations selected against (does not survive & reproduce)
3. reproduction & mutation occur
4. favorable mutations more likely to survive
5. and reproduce