chapter 10: evolution and natural selection

Question 1

population

Answer 1

group of organisms of the same species living in the same geographical region

Question 2

evolution

Answer 2

a change in allele frequencies of a population

Question 3

ideas influencing Darwin

Answer 3

1. earth is very old
2. species go extinct
3. species may change
4. earth’s features change

Question 4

traits

Answer 4

physical characteristics

Question 5

4 processes that can change evolution

Answer 5

mutation, genetic drift, mutation, natural selection

Question 6

mutation

Answer 6

alteration of base-pair sequence in DNA of an individuals gamete-producing cells that changes an alleles frequency
1. we cannot predict which individuals will have which mutations
2. cannot predict whether the mutation will be helpful, harmful, neutral

Question 7

genetic drift

Answer 7

random change in allele frequencies, unrelated to any allele’s influence on reproductive success

Question 8

gene flow (migration)

Answer 8

change in allele frequencies caused by individuals moving into/out of a population

Question 9

natural selection

Answer 9

change in allele frequencies that occurs when individuals with 1 version of veritable trait have greater reproductive success than individuals with different alleles

Question 10

fixation

Answer 10

when results of allele are 100% frequency in a population

Question 11

founder effect

Answer 11

isolation of small subgroups of larger population leading to changes in allele frequencies of the isolated group

Question 12

population bottleneck effect

Answer 12

sudden reduction in population size that can lead to changes in allele frequencies of the isolated population

Question 13

when does natural selection occur

Answer 13

1. there is variation for a trait
2. heritability
3. differential reproductive success

Question 14

differential reproductive success

Answer 14

some individuals have greater reproductive success

Question 15

sexual selection

Answer 15

traits have greater reproductive success because they make an individual more attractive

Question 16

hardy-weinberg law

Answer 16

alleles must add up to 100%

Question 17

fitness

Answer 17

measure of amount of reproduction of an individual with particular phenotype relative to reproductive output of individuals of same species with alternative phenotypes

Question 18

adaption

Answer 18

process organisms become better matched to their environment and to the specific feature that makes an organism more fit

Question 19

artificial selection

Answer 19

differential reproduction success determined by humans
- typically goal oriented

Question 20

directional selection

Answer 20

(for a trait) increases fitness at one extreme of phenotype and reduces fitness at other

Question 21

stabilizing selection

Answer 21

selection that produces greatest fitness at intermediate point of phenotype range

Question 22

disruptive selection

Answer 22

increases fitness at both ends of phenotype distribution and reduces fitness at middle value

Question 23

fossil

Answer 23

remains of an organism, usually hard parts, that have been naturally preserved

Question 24

radiometric dating

Answer 24

method of determining both relative and absolute age of object by measuring the radioactive isotopes they contain and their decay points

Question 25

fossilization represents animals that:

Answer 25

1. happen to live in the location
2. could be preserved under certain chemical conditions
3. had physical structures that could leave fossils

Question 26

biogeography

Answer 26

study and interpretation of distribution patterns of living organisms around the world
- evolution doesn’t lead to same solutions

Question 27

homologous structures

Answer 27

body structures in different organisms that although they may have been modified over time to serve different functions in different species, derived through inheritance from common evolutionary ancestor

Question 28

vestigial structures

Answer 28

structures that are no longer useful

Question 29

convergent evolution

Answer 29

process of natural selection which features of organisms not related start to resemble each other because of similar selective forces