Unit 1: vocabulary

Question 1

clathrates

Answer 1

frozen chunks of ice and methane found at the bottom of the ocean

Question 2

climate

Answer 2

long-term, predictable atmospheric conditions present in a specific area

Question 3

global climate change

Answer 3

altered global weather patterns, including a worldwide increase in temperature, due largely to rising levels of atmospheric carbon dioxide

Question 4

greenhouse effect

Answer 4

warming of Earth due to carbon dioxide and other greenhouse gases in the atmosphere

Question 5

greenhouse gases

Answer 5

atmospheric gases such as carbon dioxide and methane that absorb and emit radiation, thus trapping heat in Earth’s atmosphere

Question 6

haze-effect cooling

Answer 6

effect of the gases and solids from a volcanic eruption on global climate

Question 7

Industrial Era (Industrial Revolution)

Answer 7

period marked by the transition in manufacturing to machines. Concentrated in Great Britain, continental Europe, and the United States, and occurred during the period from around 1760 to1840

Question 8

Milankovitch cycles

Answer 8

cyclic changes in the Earth’s orbit that may affect climate

Question 9

phenology

Answer 9

study of the timing of periodic life cycle events

Question 10

solar intensity

Answer 10

amount of solar power energy the sun emits in a given amount of time

Question 11

weather

Answer 11

conditions of the atmosphere during a short period of time

Question 12

adaptive evolution

Answer 12

increase in frequency of beneficial alleles and decrease in deleterious alleles due to selection

Question 13

allele frequency (also, gene frequency)

Answer 13

rate at which a specific allele appears within a population

Question 14

bottleneck effect

Answer 14

magnification of genetic drift as a result of natural events or catastrophes

Question 15

directional selection

Answer 15

selection that favors phenotypes at one end of the spectrum of existing variation

Question 16

diversifying selection

Answer 16

selection that favors two or more distinct phenotypes

Question 17

evolutionary fitness (also, Darwinian fitness)

Answer 17

individual’s ability to survive and reproduce

Question 18

founder effect

Answer 18

event that initiates an allele frequency change in part of the population, which is not typical of the original population

Question 19

frequency-dependent selection

Answer 19

selection that favors phenotypes that are either common (positive frequency- dependent selection) or rare (negative frequency- dependent selection)

Question 20

gene flow

Answer 20

flow of alleles in and out of a population due to the individual or gamete migration

Question 21

gene pool

Answer 21

all the alleles that the individuals in the population carry

Question 22

genetic drift

Answer 22

effect of chance on a population’s gene pool genetic structure distribution of the different possible genotypes in a population

Question 23

genetic variance

Answer 23

diversity of alleles and genotypes in a population

Question 24

good genes hypothesis

Answer 24

theory of sexual selection that argues individuals develop impressive ornaments to show off their efficient metabolism or ability to fight disease

Question 25

handicap principle

Answer 25

theory of sexual selection that argues only the fittest individuals can afford costly traits

Question 26

heritability

Answer 26

fraction of population variation that can be attributed to its genetic variance

Question 27

honest signal

Answer 27

trait that gives a truthful impression of an individual’s fitness

Question 28

macroevolution

Answer 28

broader scale of evolutionary changes that scientists see over paleontological time

Question 29

microevolution

Answer 29

changes in a population’s genetic structure

Question 30

modern synthesis

Answer 30

overarching evolutionary paradigm that took shape by the 1940s and scientists generally accept today

Question 31

population genetics

Answer 31

study of how selective forces change the allele frequencies in a population over time

Question 32

population variation

Answer 32

distribution of phenotypes in a population

Question 33

relative fitness

Answer 33

individual’s ability to survive and reproduce relative to the rest of the population

Question 34

selective pressure

Answer 34

environmental factor that causes one phenotype to be better than another

Question 35

sexual dimorphism

Answer 35

phenotypic difference between a population's males and females

Question 36

stabilizing selection

Answer 36

selection that favors average phenotypes