Unit 3 Terms

Question 1

neutral mutation

Answer 1

mutation that does not result in any selective advantage or disadvantage

Question 2

harmful mutation

Answer 2

any mutation that reduces the reproductive success of an individual and is therefore selected against
-do not accumulate over time

Question 3

beneficial mutation

Answer 3

any mutation that increases the reproductive success of an organism
- are favoured by natural selection and accumulate over time

Question 4

artificial selection

Answer 4

directed breeding in which individuals that exhibit a particular trait are chosen as parents of the next generation

Question 5

immutable

Answer 5

unable to change

Question 6

fossil

Answer 6

any ancient remains, impressions, or traces of an organism, or traces of its activity that have been preserved in rocks or other mineral deposits in Earth’s crust

Question 7

paleontology

Answer 7

the scientific investigation of prehistoric life through the study of fossils

Question 8

catsatrophism

Answer 8

the theory that the pattern of fossils could be accounted for by a series of global catastrophes that wiped out most species on earth

Question 9

uniformitarianism

Answer 9

the theory that geological changes are slow and gradual and that natural laws and processes have not changed over time

Question 10

biogeography

Answer 10

the scientific study of the geographic distribution of organisms based on both living species and fossils

Question 11

homologous feature

Answer 11

a structure with a common evolutionary origin that may serve different functions in modern species

Question 12

analogous feature

Answer 12

a structure that performs the same function as another bus is not similar in origin or anatomical structure

Question 13

vestigial feature

Answer 13

a rudimentary and non-functioning or (only marginally functioning) structure that is homologous to a fully functioning structure in closely related species

Question 14

natural selection

Answer 14

the way in which nature favours the reproductive success of some individuals within a population over others

Question 15

survival of the fittest

Answer 15

a phrase that has been used to describe the process of natural selection

Question 16

adaptation

Answer 16

a characteristic or feature of a species that makes it well suited for survival or reproductive success in its environment

Question 17

radiosioptope

Answer 17

an atom with an unstable nucleus that is capable of undergoing radioactive decay

Question 18

half-life (radioactive)

Answer 18

the time required for half the quantity of a radioactive substance to undergo decay; the half-life is a constant for any given isotope

Question 19

modern evolutionary synthesis

Answer 19

the modern theory of evolution that takes into account all branches of biology

Question 20

gene pool

Answer 20

the complete set of all alleles contained within a species or population

Question 21

psurdogene

Answer 21

a vestigial gene that no longer codes for the functioning protien

Question 22

plate tectonics

Answer 22

the scientific theory that describes the large-scale movements and features of the earth’s crust

Question 23

directional selection

Answer 23

selection that favours an increase or decrease in the value of a trait from the current population average

Question 24

stabilizing selection

Answer 24

selection against individuals exhibiting traits that deviate from the current population average

Question 25

disruptive selection

Answer 25

selection that favours 2 or more variations of a trait that differ from the current population average

Question 26

sexual selection

Answer 26

differential reproductive success caused by variation in the ability to obtain mates results in sexual dimorphism and mating and courtship behaviours

Question 27

genetic drift

Answer 27

changes to allele frequency as a result of chance | - more pronounced in smaller populations

Question 28

genetic bottleneck

Answer 28

a dramatic, often temporary reduction in population size usually resulting in significant genetic drift

Question 29

Hardy-Weinberg principle

Answer 29

in large populations in which only ransom chance is at work, allele frequencies are expected to remain constant from generation to generation

Question 30

founder effect

Answer 30

genetic drift that results when a small number of individuals separate from their original population and establish a new population

Question 31

microevolution

Answer 31

changes in gene (allele) frequencies and phenotypic traits within a population and species -evolution within a species

Question 32

reproductive isolating mechanism

Answer 32

any behavioral, structural, or biochemical trait that prevents individuals of different species from reproducing successfully

Question 33

prezygotic mechanism

Answer 33

a reproductive isolating mechanism that prevents interspecies mating and fertilization

Question 34

postzygotic mechanism

Answer 34

a reproductive isolating mechanism that prevents maturation and reproduction in offspring from interspecies reproduction

Question 35

allopatric speciation

Answer 35

the formation of a new species s a result of evolutionary changes following a period of geographic isolation

Question 36

sympatric speciation

Answer 36

the evolution of populations withing the same geographic area into separate species

Question 37

adaptive radiation

Answer 37

relatively rapid evolution of a single species into any new species, filling a variety of formerly empty ecological niches

Question 38

divergent evolution

Answer 38

the large-scale evolution of a group into many different forms

Question 39

convergent evolution

Answer 39

the evolution of similar traits in distantly related species

Question 40

coevolution

Answer 40

a process in which one species evolves in response to the evolution of another species

Question 41

macroevolution

Answer 41

large-scale evolutionary changes including the formation of new species and new taxa -evolution causing speciation

Question 42

abiogenesis

Answer 42

the origin of life from non-living matter

Question 43

Cambrian explosion

Answer 43

the rapid evolution of most major animal phyla that took place over approximately 40 million years during the Cambrian period

Question 44

cladistics

Answer 44

a method of determining evolutionary relationships based on the presence or absence of recently evolved traits

Question 45

derived trait

Answer 45

a trait that has evolved relatively recently with respect to the species or groups being discussed

Question 46

synapomorphy

Answer 46

a derived trait shared by 2 or more species or groups

Question 47

theory of gradualism

Answer 47

a theory that attributes large evolutionary changes in species to the accumulation of many small and ongoing changes and processes

Question 48

theory of punctuated equilibrium

Answer 48

a theory that attributes most revolutionary changes to relatively rapid spurts of change followed by long periods of little or no change

Question 49

transitional form

Answer 49

a fossil or species intermediate in form between 2 other species in a direct line of descent

Question 50

primate

Answer 50

a group of relatively large-brained, mostly arboreal mammals that includes prosimians, monkeys, apes and humans

Question 51

prosimian

Answer 51

the group of primates that includes lemurs, lorises and tarsiers

Question 52

anthropoid

Answer 52

the group of primates that includes monkeys, apes and humans

Question 53

hominid

Answer 53

all species descended from the most recent common ancestor of chimpanzees and humans that are on the human side of lineage