Chapter 23/24/8

Front 1

Mechanisms That Change Allele Frequencies

Back 1

1. Natural Selection

2. Some individuals reproduce more than others

Front 2

Natural Selection

Back 2

alleles that increase relative fitness become more common

Front 3

Maladaptive

Back 3

alleles that reduce fitness become less common

Front 4

Genetic Drift (3)

Back 4

random loss of alleles from one generation to the next

Front 5

Bottleneck Effect

Back 5

sudden reduction in population size due to an environmental change

Front 6

Founder Effect

Back 6

alleles from an isolated population differ from the original population

ex: frequency of red allele is low in original population, several travelers to new island carry red allele, and red allele is then higher in new population

Front 7

Chance Events

Back 7

just by chance, alleles are lost

ex: frequency of red allele is low in population of lizards, only lizard with red allele gets eaten by an eagle, and the red allele is lost

Front 8

Genetic Drift Summary

Back 8

big impact on small populations

change allele frequencies by chance

can lead to a loss of genetic variation

can lead to fixation of harmful alleles

Front 9

Fixed Allele

Back 9

all individuals in a population have the same allele

Front 10

Gene Flow

Back 10

movement of alleles among populations

Front 11

Gene flow tends to..

Back 11

reduce differences between populations over time

new alleles from gene flow can be good or bad

Front 12

Speciation

Back 12

the origin of a new species

Front 13

Macroevolution

Back 13

evolutionary change above the species level (Phylum, Domain, Family, Genus)

Front 14

Morphological Species Concept

Back 14

a group of phenotypically similar organisms

Front 15

Phylogenetic Species Concept

Back 15

grouping is based on shared morphology and common ancestry

Front 16

Biological Species Concept

Back 16

individuals of the same species interbreed to produce viable, fertile offspring

cannot be applied to fossils & asexual organisms

Front 17

Prezygotic Barriers

Back 17

prevent fertilization from even happening

Front 18

Four Prezygotic Barriers

Back 18

Habitat

Temporal

Behavorial

Mechanical- try to mate but are morphologically incompatible

Front 19

Five Postzygotic Barriers

Back 19

Reduced Hybrid Viability

Reduced Hybrid Fertility

Hybrid Breakdown

Front 20

Gametic Isolation

Back 20

think sea creatures that spray sperm everywhere

after mating but before fertilization

Front 21

Reduced Hybrid Viability

Back 21

offspring die if fertilization occurs

Front 22

Reduced Hybrid Fertility

Back 22

surviving hybrid but cannot reproduce

ex: mule

Front 23

Hybrid Breakdown

Back 23

viable, fertile, but only for a limited time

Front 24

Hybrid Vigor

Back 24

phenomenon in which the hybrid is stronger and/or larger than either of the parent species

ex: liger

Front 25

Allopatric Speciation

Back 25

1. isolation of gene pools

2. evolutionary change in separate gene pools

3. reproductive isolation

Front 26

Allopatry

Back 26

species are geographically separated from each other

NOT considered a biological reproductive barrier

separate populations can still mate to produce viable, fertile offspring

Front 27

How Could Geographic Isolation Lead to Reproductive Isolation? (2)

Back 27

1. genetic drift in isolated populations

2. natural selection driving evolution to unique habitat

Front 28

Fusion

Back 28

weakening of reproductive barriers between two species that results in a single, hybridized species

ex: grolar bear

Front 29

Sympatry

Back 29

species living together in the same geographic area

Front 30

Autopolyploidy

Back 30

failure in cell division results in viable, fertile individuals with uncharacteristic chromosome number

Front 31

Autopolyploidy happens in _______ generation(s) and __________ species

Back 31

in a single generation and a single species

common in plants

Front 32

Allopolyploidy happens in ______ generation(s) and ______ species

Back 32

multiple generations and at least two species

Front 33

3 Hybrid Zones

Back 33

1. Reinforcement

2. Fusion

3. Stability (stay in hybrid zone forever)

Front 34

2 Patterns of Speciation

Back 34

1. Punctuated Equilibrium

2. Gradual

Front 35

Punctuated Equilibrium

Back 35

long periods of equilibrium punctuated by short periods of rapid evolutionary change

Front 36

Gradual

Back 36

small changes accumulate over long periods of time, resulting eventually in a new species

A LOT of intermediates

Front 37

Metabolism

Back 37

the sum total of all the chemical reactions that take place in the body

Front 38

Catabolic

Back 38

reactions that break down complex molecules into simpler ones

reactions that release energy

Front 39

Anabolic

Back 39

reactions that use energy to produce more complex molecules

Front 40

Kinetic Energy

Back 40

energy of motion

Front 41

Potential Energy

Back 41

energy of an object resulting from its structure or position

Front 42

Chemical Energy

Back 42

energy can be released through chemical reactions

Front 43

Heat Energy

Back 43

total kinetic energy of all molecules in a substance

Front 44

First Law of Thermodynamics

Back 44

energy cannot be created or destroyed, but it can be transformed

Front 45

Second Law of Thermodynamics

Back 45

every energy transformation increases entropy in the universe

Entropy- disorder (heat energy)

Front 46

Spontaneous Reaction

Back 46

will occur without any energy input and will increase entropy in the universe

Front 47

Free Energy

Back 47

energy that can do work when temperature and pressure are uniform, as in a living cell

Front 48

Exergonic Reaction

Back 48

proceeds with a net release of free energy and is spontaneous

Front 49

Endergonic Reaction

Back 49

absorbs free energy from its surroundings and is nonspontaneous

Positive Delta G

Ex: photosynthesis

Front 50

Open System

Back 50

system exchanges energy with the outside

Front 51

Closed System

Back 51

system that does not exchange energy with outside sources

Front 52

Work Done By Cells (3)

Back 52

1.Transport (getting one thing from one side of the cell to the other)

2. Chemical

3. Mechanical (flailing, moving around)

Front 53

Energy Coupling

Back 53

using an exergonic reaction to power an endergonic reaction

Front 54

Hydrolysis

Back 54

breaking of chemical bonds with water

Front 55

Catalyst

Back 55

substance that speeds up chemical reactions

Front 56

Enzyme

Back 56

a catalytic protein

ex: sucrase, lactase, all end in ase

Front 57

Substrate

Back 57

reactants that join with enzyme

Front 58

Active Site

Back 58

where substrate joins enzyme

Front 59

Allosteric Site

Back 59

binding site other than active site

Front 60

Free Energy Activation (Ea)

Back 60

free energy required to initiate a reaction