Chapter 10 - Evolutionary Genetics

Question 1

central concept in biology

Answer 1

evolution

Question 2

one of the foundations of evolution

Answer 2

genetics

Question 3

group of individuals of the same species

Answer 3

population

Question 4

• series of partial or complete and irreversible transformations of the genetic structure of a population based principally on altered interaction with the environment
• chance processes, interacting with a changing environment, generated complex structures and organs that now have purposes which were not planned or designed

Answer 4

organic evolution

Question 5

Requirements for Evolution

Answer 5

1. heritable variation
2. limited environmental opportunities
3. changing environments

Question 6

genetic mechanism that is not perfect but produces offspring that are sometimes slightly different from their parent/s

Answer 6

heritable variation

Question 7

insufficient resources for all individuals to survive and reproduce, leading to competition for necessary resources

Answer 7

limited environmental opportunities

Question 8

as conditions change, different individuals are best able to survive and reproduce

Answer 8

changing environments

Question 9

Forces that modify gene frequencies in populations

Answer 9

1. mutation
2. migration
3. natural selection
4. genetic drift
5. gene recombination

Question 10

increases variability within a population

Answer 10

mutation

Question 11

adds genetic variability to a population

Answer 11

migration

Question 12

• decreases genetic variability through elimation of unfavorable mutations
• results in the perpetuation of those life forms having favorable characteristics that enable them to adapt to a specific environment

Answer 12

natural selection

Question 13

results in the chance elimination of genotypes due to small population size

Answer 13

genetic drift

Question 14

causes reshuffling of genes to produce new gene combinations for acceptance or rejection by selective forces of evolution

Answer 14

gene recombination

Question 15

identification by humans of desirable traits in plants and animals, and the steps taken to enhance and perpetuate those traits in future generations

Answer 15

Artificial selection

Question 16

genetic base in artificial selection

Answer 16

narrow

Question 17

genetic base in natural selection

Answer 17

broad

Question 18

• change in population’s gene pool over a succession of generations
• occurs over relatively brief period of time

Answer 18

microevolution

Question 19

• total collection of genes in a population at any given time
• reservoir from which members of next generation derive their genes

Answer 19

gene pool

Question 20

genetic drift that results from event that drastically reduces population size

Answer 20

bottleneck effect

Question 21

refers to the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population

Answer 21

founder effect

Question 22

Three Evolutionary Patterns

Answer 22

1. divergent evolution
2. convergent evolution
3. parallel evolution

Question 23

• occurs when members of a species are placed in different environmental conditions
• members of population may gradually develop into different species with no particular point in time for their separation

Answer 23

divergent evolution

Question 24

• refers to the development of superficial resemblances between organisms of different ancestries
• these groups, which are unrelated by descent, but living under similar environmental conditions can exhibit similarities in habits and general appearances

Answer 24

convergent evolution

Question 25

herbaceous plant or shrub with milky latex and very small, typically greenish, flowers

Answer 25

spurge

Question 26

- two organisms acquire similar characteristics independently of one another - have stemmed from related ancestries - akin, yet distinguishable from convergence

Answer 26

parallel evolution

Question 27

Modes of Selection

Answer 27

1. directional selection 2. stabilizing selection 3. disruptive selection

Question 28

ex. of directional selection

Answer 28

english peppered moths

Question 29

ex. of stabilizing selection

Answer 29

horseshoe crab

Question 30

ex. of disruptive selection

Answer 30

African swallowtail

Question 31

process of splitting a genetically homogenous population into two or more populations that undergo genetic differentation and reproductive isolation

Answer 31

speciation

Question 32

The Rate of Speciation

Answer 32

1. phyletic gradualism 2. quantum speciation

Question 33

speciation is a microevolutionary event resulting from the accumulation of many small gene differences over time under the influence of natural selection

Answer 33

phyletic gradualism

Question 34

- stochastic or catastrophic speciation - evolutionary events occur suddenly and intermittently

Answer 34

quantum speciation

Question 35

Models of Quantum Speciation

Answer 35

1. Punctuated Equilibrium 2. Founder-Flush Theory

Question 36

- idea that evolution occurs in spurts instead of following the slow, but steady path that Darwin suggested - Long periods of stasis with little activity in terms of extinctions or emergence of new species are interrupted by intermittent bursts of activity

Answer 36

Punctuated equilibrium

Question 37

genetic evolution is in some way different in a population that is founded by a small number of individuals and that subsequently grows rapidly

Answer 37

Founder-flush theory

Question 38

Models of Speciation (Recent, most developed)

Answer 38

1. allopatric speciation 2. sympatric speciation 3. stasipatric speciation

Question 39

- geographic features such as lakes, rivers, or mountains act as barriers to gene flow between population - physical isolation is the first step in the process of evolution

Answer 39

allopatric speciation

Question 40

formation of species from populations that live in the same geographic range and do not become geographically isolated

Answer 40

sympatric speciation

Question 41

- rapid speciation that may occur among small breeding populations that are not completely isolated genetically or spatially. - formation of new species as a result of chromosomal rearrangements

Answer 41

stasipatric speciation

Question 42

Human Evolution

Answer 42

1. loss of alleles 2. increasing allele frequencies

Question 43

branch of systematics that attempts to construct phylogenetic trees based on the presence of shared derived characters

Answer 43

cladistics

Question 44

Two types of Isolation

Answer 44

1. Geographical Isolation 2. Reproductive Isolation

Question 45

Two types of Reproductive Isolation

Answer 45

1. Prezygotic Isolation 2. Postzygotic Isolation

Question 46

Prezygotic Isolation

Answer 46

1. ecological 2. seasonal 3. ethological 4. physiological 5. mechanical 6. gametic mortality

Question 47

Postzygotic Isolation

Answer 47

1. cytological 2. zygotic mortality 3. hybrid inviability 4. hybrid sterility 5. hybrid breakdown