Chapter 10: Evolution

Question 1

evolution

Answer 1

-change in allele frequencies in a population

Question 2

measuring age

Answer 2

• radiometric dating

- paleomagnetic dating

Question 3

old conditions of Earth

Answer 3

• no free oxygen until cyanobacteria, leading to the Cambrian Explosion
• carbon, nitrogen, water
• lightning and U.V. radiation provided energy

Question 4

homologous structures

Answer 4

• same structure, different function

- reflect common ancestry

Question 5

analogous structures

Answer 5

• different structure, same function

- shows adaptation to similar environments

Question 6

vestigial structures

Answer 6

-no longer useful (appendix)

Question 7

adaptive radiation

Answer 7

• animals adapt and fill every available niche

- emergence of numerous species from a common ancestor introduced into an environment

Question 8

Hutton

Answer 8

-gradualism: Earth was molded by gradual change

Question 9

Lamarck

Answer 9

-inheritance through use and disuse

Question 10

directional selection

Answer 10

-favors one extreme (antibiotic resistance)

Question 11

diversifying selection

Answer 11

-favors 2 extremes

Question 12

stabilizing selection

Answer 12

-favors individuals in the middle

Question 13

balanced polymorphism

Answer 13

-one population divided into 2 types

Question 14

sexual dimorphism

Answer 14

-difference in appearance between males and females

Question 15

sexual selection

Answer 15

-selection based on variation in secondary sexual characteristics related to competing for mates

Question 16

cline

Answer 16

-graded variation in phenotype of an organism

Question 17

frequency-dependent selection

Answer 17

• AKA minority advantage

- decrease frequency of common phenotypes

Question 18

genetic drift

Answer 18

-change in a gene pool due to chance

Question 19

bottleneck effect

Answer 19

-natural disasters that reduce the size of a population unselectively, resulting in the loss of genetic variation

Question 20

founder effect

Answer 20

• small population breaks away from old population to colonize a new area
• alleles are not represented equally

Question 21

gene flow

Answer 21

• movement of alleles in and out of a population

- increases diversity

Question 22

Hardy-Weinberg conditions for no evolution

Answer 22

• population must be large
• isolated from other populations
• no mutations
• mating random
• no natural selection

Question 23

species

Answer 23

-population whose members have the potential to interbreed and produce viable,fertile offspring

Question 24

reproductive isolation

Answer 24

• prezygotic: habitat, temporal, behavioral, mechanical, gametic
• postzygotic: hybrid sterility, hybrid inviability (dies), and hybrid breakdown (eventually becomes more weak or sterile through generations)

Question 25

speciations

Answer 25

-creation of new species

Question 26

allopatric speciation

Answer 26

-caused by geographic isolation

Question 27

sympatric speiation

Answer 27

• no geographic barrier
• polyploidy
• habitat, behavioral (nocturnal vs. daytime), temporal (become sexuallymature in different seasons), and reproductive isolation

Question 28

polyploidy

Answer 28

-more than 2 complete sets of chromosomes, can form from nondisjunction (no separation of homologous chromosomes, leading to 4n etc.)

Question 29

convergent evolution

Answer 29

-unrelated species occupy the same environment, leading to similar adaptations

Question 30

parallel evolution

Answer 30

-2 related species that have similar evolutionary adaptations after their divergence from a common ancestor

Question 31

coevolution

Answer 31

-influence of two interacting populations on the evolutionary history

Question 32

punctuated equilibrium

Answer 32

• popular theory of evolution

- new species appear after long periods of stasis

Question 33

Miller and Urey

Answer 33

-proved that organic molecules formed in early conditions

Question 34

anaerobic hetertrophic prokaryotes

Answer 34

-first cells on earth

Question 35

endosymbiosis

Answer 35

• chloroplast and mitochondria have their own DNA
• DNA C and M is more like prokayotic DNA than eukayotic (not wrapped with histones)
• have double membranes (inner belongs to symbiont, outer belongs to host plasma membrane)