Unl Life 121 Exam 1

Front 1

discretionality of evolution

Back 1

species change over time and are adapted to their environment

Front 2

use and disuse

Back 2

body parts that are used become larger and stronger, while those that are not used deteriorate

Front 3

inheritance of acquired characteristics

Back 3

characteristics could be passed to offspring

Front 4

descent with modification

Back 4

organisms evolve through natural selection and adapt to their environment

Front 5

adaptation

Back 5

inherited characteristics that enhance survival and reproduction in a specific environment

Front 6

natural selection

Back 6

a process in which individuals with particular inherited traits will survive and reproduce at higher rates than those individuals without the traits

Front 7

binomial nomenclature

Back 7

two part scientific name of a species

Front 8

phylogeny

Back 8

the evolutionary history of a species or group of related species

Front 9

homology

Back 9

phenotypic and genetic similarities due to shared ancestry

Front 10

analogy

Back 10

similarities resulting from convergent evolution such as similar structures

Front 11

clade

Back 11

group of species descended from a common ancestor

Front 12

monophyletic

Back 12

ancestor and all of its descendants

Front 13

paraphyletic

Back 13

ancestor and part of its descendants

Front 14

polyphyletic

Back 14

group composed of members with different ancestors

Front 15

shared ancestral character

Back 15

trait that predates branching of a clade

Front 16

shared derived character

Back 16

trait that is unique to a clade

Front 17

microevolution

Back 17

adaptation

Front 18

macroevolution

Back 18

speciation

Front 19

phenotypic variation

Back 19

variation in physical and physiological traits among individuals

Front 20

genetic variation

Back 20

differences among individuals in their genetic information

Front 21

population

Back 21

a group of organisms of the same species that inhabit the same area and interbreed

Front 22

gene pool

Back 22

all copies of every type of allele at all loci in every individual in a population

Front 23

locus

Back 23

specific portion of chromosome where one gene is located

Front 24

allele

Back 24

versions of gene that may produce a phenotypic effect

Front 25

gene flow

Back 25

transfer of alleles into and out of population due to the movement of fertile individuals

Front 26

genetic drift

Back 26

process in which random events cause unpredictable fluctuations in allele frequencies from on generation to the next

Front 27

founder effect

Back 27

small number of individuals establish a new population

Front 28

bottleneck effect

Back 28

occurs when a population is reduced in number

Front 29

directional selection

Back 29

conditions favor one extreme of a phenotypic range

Front 30

disruptive selection

Back 30

individuals at both extremes of a phenotypic range are favored over intermediate phenotypes

Front 31

stabilizing selection

Back 31

selection favors intermediate types and acts against extreme phenotypes

Front 32

speciation

Back 32

process by which new species arise

Front 33

species

Back 33

a set of individuals that are closely related by descent from a common ancestor and can reproduce viable offspring with each other but not with members of any other species

Front 34

phylogenetic species concept

Back 34

smallest group of individuals descended from a common ancestor and who all possess a combination of shared derived traits

Front 35

morphological species concept

Back 35

group of individuals that appear identical by morphological criteria

Front 36

biological species concept

Back 36

one or more populations interbreeding under natural conditions and producing viable fertile offspring and reproductively isolated from other such populations

Front 37

habitat isolation

Back 37

species occupy different habitats within overlapping ranges and rarely encounter each other

Front 38

temporal isolation

Back 38

species breed during different times or seasons

Front 39

behavioral isolation

Back 39

operates through courtship rules and other behavioral patterns

Front 40

mechanical isolation

Back 40

morphological differences prevent mating

Front 41

gametic isolation

Back 41

male and female gametes fail to unite

Front 42

reduced hybrid viability

Back 42

hybrid zygotes fail to develop in utero or reach sexual maturity

Front 43

reduced hybrid fertility

Back 43

hybrid sterility

Front 44

hybrid breakdown

Back 44

offspring of hybrids are weak or infertile

Front 45

allopatric speciation

Back 45

a population forms a new species while geographically isolated from parent generation

Front 46

sympatric speciation

Back 46

a subset of a population forms a new species without geographic speciation

Front 47

polyploidy

Back 47

the presence of extra set of chromosomes due to accidents during cell division

Front 48

autopolyploidy

Back 48

an individual with more than two chromosomes sets derived from one species

Front 49

allopolyploidy

Back 49

a species with multiple sets of chromosomes derived from different species

Front 50

hybrid zone

Back 50

region where species with incomplete reproductive barriers come into contact and mate producing hybrids

Front 51

reinforcement

Back 51

hybrids are not fit and disappear

Front 52

fusion

Back 52

reproductive barriers are overcome by gene flow and two species fuse into a single species

Front 53

stability

Back 53

hybrid populations are stable as a result of surviving and reproducing better than individuals of parents species