Chapter 18 - Evolution of Populations

Question 1

All the genes, including all the different alleles for each gene, that are present in a population at any 1 time

Answer 1

Gene Pool

Question 2

Number of times that an allele occurs in a gene pool compared w/ the # of alleles in that pool for the same gene

Answer 2

Allele Frequency

Question 3

Trait controlled by 1 gene that has 2 alleles

Answer 3

Single-Gene Trait

Question 4

Trait controlled by 2 or more genes

Answer 4

Polygenic Trait

Question 5

Evolution involves any change in the frequency of ___ in a population over time.

Answer 5

alleles

Question 6

An ___ ___ is any genetically controlled trait that increases an individual’s fitness.

Answer 6

evolutionary adaptation

Question 7

1. Mutation
2. Genetic recombination during sexual reproduction
3. Lateral gene transfer

Answer 7

sources of genetic variation

Question 8

The # of ___ produced for a trait depends on how many genes control the trait.

Answer 8

phenotypes

Question 9

The bell-shaped curve on a graph measuring a polygenic trait

Answer 9

normal distribution

Question 10

Form of natural selection in which individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve

Answer 10

Directional Selection

Question 11

Form of natural selection in which individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve

Answer 11

Stabilizing Selection

Question 12

Natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals near the middle of the curve

Answer 12

Disruptive Selection

Question 13

Sum total of all the different forms of genetic info. carried by a particular species, or by all organisms in Earth

Answer 13

Genetic Drift

Question 14

A change in allele frequency following a dramatic reduction in the size of a population

Answer 14

Bottleneck Effect

Question 15

Change in allele frequencies as a result of the migration of a small subgroup of a population

Answer 15

Founder Effect

Question 16

Situation in which allele frequencies in a population remain the same

Answer 16

Genetic Equilibrium

Question 17

Principle that states that allele frequencies in a population remain constant unless 1 or more factors cause those frequencies to change

Answer 17

Hardy-Weinberg Principle

Question 18

The selection of mates based on heritable traits

Answer 18

Sexual Selection

Question 18

The movement of genes into or out of a population

Answer 18

Gene Flow

Question 18

1. Directional selection
2. Stabilizing selection
3. Disruptive selection

Answer 18

3 types of selection can be affected by the fitness of their phenotypes by natural selection on polygenic traits

Question 19

In small populations, individuals that carry a particular allele may leave more ___ than other individuals, just by chance.

Answer 19

descendants

Question 20

1. Nonrandom mating
2. Small population size
3. Gene flow from immigration/emigration
4. Mutations
5. Natural selection

Answer 20

5 conditions that the Hardy-Weinberg principle predicts can disturb genetic equilibrium and cause evolution to occur

Question 21

Group of homeotic genes clustered together to determine the head to tail identity of body parts in animals; all contain the homeobox DNA sequence

Answer 21

Hox Gene

Question 22

One way new genes can evolve is through ___, followed by ___, of existing genes.

Answer 22

duplication; modification

Question 23

Small changes in ___ ___ activity during embryological development can produce large changes in adult animals.

Answer 23

Hox gene

Question 24

A ___ ___ uses mutation rates in DNA to estimate the time that 2 species have been evolving independently.

Answer 24

molecular clock

Question 25

Layers of sedimentary rock, volcanic ash or amber trap and preserve fossils

Answer 25

fossil record

Question 26

1. includes actual trapped organisms, footprints, and casts of organisms
2. within sedimentary rock layers give a record of the succession of organisms that have populated Earth throughout a long period of time

Answer 26

fossils

Question 27

___ ___ show the change over time in a species.

Answer 27

Transitional fossils

Question 28

___ proposed his Theory
of ___ ___ in 1912, based on the similarity of fossil organisms on different continents.

Answer 28

Wegener; Plate Tectonics

Question 29

The Theory of Plate Tectonics explains how current organisms could have shared a ___ ___ and the geographical distribution of living species and fossils on ___ ___.

Answer 29

common ancestor; different continents

Question 30

Genetic sequencing of mitochondrial b-cytochrome DNA material measures the ___ differences, which creates a molecular clock.

Answer 30

mutation

Question 31

Organisms not closely related independently evolve similar traits as a result of having to adapt to similar environments or ecological niches is ___ ___.

Answer 31

convergent evolution

Question 32

___ ___ encode the characteristics of ‘position’, ensuring that the correct structures form in the correct places of the body.

Answer 32

Hox proteins

Question 33

According the the Hardy-Weinberg principle, a population’s allele and genotype frequencies are ___ unless there is some type of evolutionary force acting on them.

Answer 33

constant

Question 34

A change in a population’s gene pool over a secession of generations; evolutionary changes in single species over relatively brief periods of geological time

Answer 34

microevolution

Question 35

1. Genetic Drift
2. Gene Flow
3. Mutation
4. Non-random Mating
5. Natural Selection

Answer 35

5 mechanisms of microevolution

Question 36

The Founder Effect results in the random change of the ___ ___.

Answer 36

gene pool

Question 37

Formation of a new species

Answer 37

Speciation

Question 38

Separation of a species/population so that they no longer interbreed and evolve into separate species

Answer 38

Reproductive Isolation

Question 39

Form of reproductive isolation in which 2 populations develop differences in courtship rituals/other behaviors that prevent them from breeding

Answer 39

Behavioral Isolation

Question 40

Form of reproductive isolation in which 2 populations are separated by geographic barriers, (rivers, mountains, bodies of water) leading to the formation of 2 separate subspecies

Answer 40

Geographic Isolation

Question 41

Form of reproductive isolation in which 2 or more species reproduce at different times

Answer 41

Temporal Isolation

Question 42

The shuffling of _ that occur during sexual reproduction cannot change the allele frequencies.

Answer 42

genes

Question 43

Evolutionary change is seen as ___ ___ changes in a population over time.

Answer 43

allele frequency

Question 44

Hardy-Weinberg equations (symbols)

Answer 44

p² + 2pq + q² = 1
p + q = 1

Question 45

We would expect the allele frequencies to stay the same if the population is in ___ ___ Equilibrium and can be applied to the next generation.

Answer 45

Hardy-Weinberg

Question 46

mutations, small populations, nonrandom mating, emigration/immigration (gene flow), natural selection

Answer 46

what evolutionary change is caused by