21.3

Question 1

conditions for natural selection

Answer 1

1. variation
2. differences in survival and reproduction
3. heritability

Question 2

variation

Answer 2

individuals within a population are variable

Question 3

differences in survival and reproduction

Answer 3

in every generation, some variants are more successful at surviving and reproducing than others, those with more success are said to have a higher “fitness”

Question 4

heritabiliity

Answer 4

variations among individuals are passed from parent to offspring

Question 5

natural selection

Answer 5

process that occurs when environmental conditions affect which individuals produce the most offspring
ex: selection to avoid predators, match climatic conditions, pesticide resistance, microbial resistance
outcome depends on fitness and allele frequency

Question 6

interactions among evolutionary forces

Answer 6

don’t always act independently; can work together or in opposition
mutations and genetic drift can counter selection
gene flow can either promote or prevent evolutionary change

Question 7

artifical selection

Answer 7

occurs when humans select for certain characteristics
-selective breeding

Question 8

natural selection vs evolution

Answer 8

natural selection is a process that leads to evolution
evolution refers to the historical record of change through time, it is the outcome of natural selection