Chapter 22 - Descent with Modification: A Darwinian View of Life

Question 1

Evolution: “descent with modification”

Answer 1

a phrase Darwin used to summarize the process by which species accumulate differences from their ancestors as they adapt to different environments over time

Question 2

Evolution -

Answer 2

a change in the genetic composition of a population from generation to generation

Question 3

Adaptations -

Answer 3

inherited characteristics of organisms that enhance their survival and reproduction in specific environments

Question 4

Natural selection -

Answer 4

a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals

Question 5

Evolution is a process in which both ______ and ______ can be observed.

Answer 5

descent and modification

Question 6

Scientists estimate that over ____ of all species that have ever lived are now extinct

Answer 6

99%

Question 7

Artificial selection -

Answer 7

process in which humans have modified other species over many generations by selecting and breeding individuals for desired traits

Question 8

Descent -

Answer 8

shared ancestry, resulting in shared characteristics

Question 9

Modification -

Answer 9

the accumulation of differences

Question 10

____________ is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals because of those traits.

Answer 10

Natural selection

Question 11

Over time, natural selection can increase the frequency of __________ that are favorable in a given environment

Answer 11

adaptations

Question 12

If an environment changes, or if individuals move to a new environment, natural selection may result in adaptation to these new conditions, sometimes _____ ____ __ ___ ______.

Answer 12

giving rise to new species

Question 13

individuals do not evolve; [what does]

Answer 13

the population evolves over time

Question 14

natural selection ________ or _________ only those heritable traits that differ among the individuals in a population

Answer 14

amplifies or diminishes

Question 15

A drug does not create resistant pathogens; it ___________

Answer 15

selects for resistant individuals that are already present in the population

Question 16

In species that produce new generations in short periods of time, evolution by natural selection can occur __________

Answer 16

rapidly

Question 17

Natural selection depends on _____ and ______. It favors those characteristics in a genetically variable population that provide an advantage in that ______, _______ ___________

Answer 17

time and place ; current, local environment

Question 18

Homology -

Answer 18

similarity resulting from common ancestry

Question 19

Homologous structures -

Answer 19

represent variations on a structural theme that was present in a common ancestor; share common ancestry, but not necessarily similar function

Question 20

Vestigial structures -

Answer 20

remnants of features that served a function in the organism’s ancestors

Question 21

An evolutionary tree -

Answer 21

a diagram that reflects evolutionary relationships among groups of organisms

Question 22

Analogous structures -

Answer 22

share similar functions, but not common ancestry

Question 23

Biogeography -

Answer 23

the scientific study of the geographic distributions of species

Question 24

Organisms share characteristics because of common descent -

Answer 24

homology

Question 25

Convergent evolution

Answer 25

when natural selection affects independently evolving species in similar environments in similar ways