Section 5

Question 1

evidence of evolution

Answer 1

chemical analysis of early atmosphere and measurements of radioactive elements in fossils and rocks

Question 2

Earth’s early atmosphere

Answer 2

believed to be CO2, N2, and H2O vapor
Oxygen didn’t exist because it’s too chemically reactive, plus there were no aerobic bacterium or plants yet to generate it

Question 3

Miller-Urey Experiment

Answer 3

1950s, demonstrated spontaneous production of organic molecules from the mixture of simple compounds

Question 4

1977 Australian researchers

Answer 4

discovered amino acids on a meteor, the idea that life could be influenced from outside our ecosystem

Question 5

evolution of 1st prokaryotic cells

Answer 5

amino acids → proteins, RNA → membrane bound globs + matter from environment (grow and divide) → 1st prokaryotic cells (biologically evolved under water, away from harmful UV radiation)

Question 6

prokaryotes

Answer 6

no distinct nucleus, all cellular functions exist within the membrane-bound single cell

Question 7

evolution

Answer 7

is a change in the genetic makeup of a population occurring through successive generations of sexual reproduction

Question 8

theory of evolution

Answer 8

supported by many biologists, based on the idea that all current species descended from earlier species, explains diversity of life

Question 9

microevolution

Answer 9

small changes in a population

Question 10

macro evolution

Answer 10

long-term changes within an entire group or species

Question 11

endosymbiosis

Answer 11

process in which prokaryotes evolved into eukaryotes

Question 12

Microevolution

Answer 12

small genetic changes that a population experiences over generations, developing generic variability, creating possibility for evolution

Question 13

alleles

Answer 13

different molecular forms of the same genes in members of a population, reason for genetic variability

Question 14

mutation

Answer 14

only source of new alleles, occur randomly when there are random mistakes in coding genetic instructions, advantageous alleles are rare and result in new genetic combination (potential of becoming microevolution)

Question 15

deleterious

Answer 15

dangerous/harmful mutations, offspring won’t survive, develop, and reproduce

Question 16

natural selection

Answer 16

helpful gene is created and kept as result of adaptation and different reproduction, favors individuals, not genes

Question 17

directional natural selection

Answer 17

favors the different, shift in gene frequencies (can be due to environmental conditions)
example: England peppered moths

Question 18

stabilizing natural selection

Answer 18

favors the average, abnormal genes don’t have an advantage and are eliminated
ex: birth weight of babies 5-9 lbs, can be dangerous if too low/high

Question 19

disruptive natural selection

Answer 19

aka diversifying selection, favors abnormal, environmental conditions favor individuals on extremes, mid-range is reduced
ex: Darwin’s finches in Galapagos Islands, beak variation, wide beaks or narrow thin

Question 20

gene flow

Answer 20

enhances variation in a population, refers to the flow of genes from one population of species to another, sustained gene flow between two groups results in a combination of both pools

Question 21

genetic drift

Answer 21

completely stable genes, frequency of the different gene forms called alleles in a population, changes in allele frequency of a population’s gene pool, effective genetic drift is due to chance and more evident in small populations

Question 22

bottleneck effect

Answer 22

unusual situation, usually catastrophic, large part of population isn’t allowed to reproduce and is eliminated

Question 23

founder effect

Answer 23

few individuals go off and populate a new area, gene pool is understandably diminished, big potential for mutations
ex: Amish population

Question 24

basis of microevolution

Answer 24

mutation + natural selection = the basis of microevolution

Question 25

Co-evolution

Answer 25

adaptation follows adaptation, each population keeps up with the other example: as a cactus species evolves defenses like longer thorns, birds that feast on their flesh evolve to have longer, thinner beaks to avoid harm

Question 26

adaptations

Answer 26

inherited traits that allow organism to survive and reproduce within their environment

Question 27

macroevolution

Answer 27

long term evolutionary changes among an entire group or species, long time scale

Question 28

Gradualism Model

Answer 28

evolutionary change occurs gradually, over many millions of years, that accumulated small changes lead to the eventual of multiple different species

Question 29

Punctuated Equilibrium Model

Answer 29

state that perhaps there are long periods of relatively little change, punctuated by brief periods of rapid change

Question 30

speciation

Answer 30

describes the evolution of one species into two in response to environmental changes, mechanism for speciation occurs via reproductive isolation

Question 31

four basic modes of speciation

Answer 31

allopatric, peripatric, parapatric, and sympatric allopatric and peripatric = geographical differences parapatric and sympatric = unequal gene flow

Question 32

allopatric speciation

Answer 32

geographic isolation, occurs when a significant portion of the original population is physically separated from the rest

Question 33

peripatric speciation

Answer 33

geographic isolation, small group breaks off from larger group, similar to allopatric, but population is small and peripheral

Question 34

parapatric speciation

Answer 34

species is spread out, individuals are more likely to mate with geographic neighbors than with individuals farther away in the population's range

Question 35

sympatric speciation

Answer 35

no physical barriers, spontaneous exhibition of unique behavior patterns, causes them to mate non-randomly with other individuals with the same unique behavior pattern

Question 36

divergent evolution

Answer 36

result of speciation when a structure with a shared origin evolves to be used for the unique environments

Question 37

ecological niche

Answer 37

not a physical location, but occupation and habits

Question 38

fundamental niche

Answer 38

all possible conditions an organism can survive

Question 39

realized niche

Answer 39

condition organism is actually surviving

Question 40

mass extinctions

Answer 40

abrupt increase in extinctions, catastrophic, global, 75% loss of species

Question 41

adaptive radiation

Answer 41

new species radiation out from common/ancestral DNA with heritable traits

Question 42

biodiversity

Answer 42

variety of life

Question 43

ecological niche

Answer 43

range of tolerance, available nutrients physical space, biotic and abiotic interactions, role in energy flow and matter cycling

Question 44

generalist species

Answer 44

broad range of conditions, food variety and many different locations ex: racoons

Question 45

specialist species

Answer 45

specific habitat, narrow range of conditions, one type of food, and unique niche ex: koala - eucalyptus (poisonous to other animals)