chapter 12 questions
Natural selection requires
genetic diversity
Mate choice, such as in sexual selection,
leads to nonrandom mating.
What scientist was the first to propose a mechanism for how species could change through repeated use or disuse of a body part?
Lamarck
Migration of individuals from one population to another
creates gene flow between populations.
Rock layers at the bottom of a geologic deposit are the
oldest.
Who was one of the first scientists to suggest that species arose from ancestors and were changing?
Buffon
A book written by Thomas Malthus that influenced Charles Darwin's formulation of natural selection was titled
Essay on the Principle of Population.
Select the name of the scientist who first stated that the Earth was older than 6,000 years.
Lyell
When multiple alleles of a gene persist indefinitely in a population at more or less constant frequencies, then what is occurring?
balanced polymorphism
If two species that live on opposite sides of the planet share common characteristics and live in similar habitats, then these two species have undergone
convergent evolution.
Gradual genetic changes in organisms from an ancestral species describes
descent with modification.
Natural selection, mutation, genetic drift, nonrandom mating, and gene flow are all mechanisms of ______ and can change allele frequencies in populations.
evolution
Descent with modification describes the process of
evolution.
What describes how genetic drift occurs?
gain or loss of alleles by chance
The spread of plant pollen by wind for several miles to a new population is an example of
gene flow.
The founder effect is an example of what mechanism of evolution?
genetic drift
The modern evolutionary synthesis connects natural selection and
genetic variation that arises by mutation.
Lyell's idea about fossils and the age of the Earth led to the conclusion that
gradual changes occurred in some organisms and that these could be preserved in the fossil record.
As proposed by James Hutton, the theory of uniformitarianism states that
gradual geological processes such as erosion and sedimentation that act in modern times also occurred in the past.
Evolutionary theory
has developed over several centuries.
Select all of the following that are true about the heterozygous genotype in the situation of heterozygote advantage.
has greater fitness than homozygous genotypes can contain harmful alleles
When allele and genotype frequencies are not changing between generations, the population is said to be
in Hardy-Weinberg equilibrium.
A(n) ______ does not evolve because alleles do not change; however, a(n) ______ can evolve because allele frequencies can change
individual; population
A population consists of
interbreeding members of the same species.
Select all the examples of nonrandom mating.
mate choice based on social position choosing mates based on certain characteristics mating only within a specific group
What mechanism of evolution changes the genetic makeup of a population by favoring alleles that increase reproductive success?
natural selection
In artificial selection, mating is
nonrandom.
Sexual selection is a special form of natural selection in which individuals vary in ability to
obtain mates.
The entire collection of the genes and their alleles in a population is called the gene
pool
In the bottleneck effect, what alleles are lost when a population's size drops is
random.
A difference in the appearance between males and females of a species is called
sexual dimorphism.
Human birth weight is an example of a type of natural selection called _______ selection.
stabilizing
When the intermediate phenotype of a trait is being selected for and the extreme phenotypes are being selected against, the population is probably undergoing
stabilizing selection.
A mutation can affect evolution in a species only if
subsequent generations inherit it.
Prior to newer geological ideas of the 1700s and later, many people believed that Earth was relatively ______ and that species were ______.
young; unchangeable
A precise definition of evolution is the
genetic change in a population over multiple generations.
A chance change in a population's allele frequencies, such as after a drastic reduction in population size, is the root of what force of evolution?
genetic drift
In a bird species, when females have inconspicuous coloration and males are brightly colored, this is an example of
sexual dimorphism.
What increases genetic variability within a species through shuffling and reshuffling of parental alleles to produce genetically different offspring?
sexual reproduction
To calculate an allele frequency, you should divide the number of copies of that allele by the total number of ______ in the population for that gene.
alleles
True or false: Charles Darwin was the first to attempt to explain how the diversity of life arose.
False
In a population of 100 individuals, 36 of the individuals are homozygous recessive (aa) for a particular gene. What is the frequency of that genotype?
0.36
Use the equation p2 + 2pq + q2 = 1.0 to solve the following problem. In a population of 100 squirrels there are 64 black ones, and the remaining are white. Black (B) is the dominant allele, and white (b) is the recessive allele. If the population is in Hardy-Weinberg equilibrium, what is the frequency of the black squirrels that are heterozygous (Bb) for their coat color?
0.48
What is the genotype frequency of CC if 320 individuals have the genotype CC in a population of 2,000 individuals?
0.16
Select all the statements that describe Lamarck's ideas about the origin of species.
Any physical changes that happen to the parents during their lives can be passed on to the next generation. Organisms that use a body part repeatedly increase their abilities.
Selection of dairy cows that produce more milk for human consumption is an example of ______ selection, and selection of light-colored moths over dark-colored moths by a bird predator is an example of ______ selection.
Artificial, Natural
___selection occurs when humans select for desirable characteristics in crosses of dogs, horses, or other organisms, whereas _____selection occurs when environmental factors select for adaptive traits.
Artificial;natural
How did natural selection shape the evolution of finches on the Galápagos Islands?
Birds with different heritable differences were able to better survive and reproduce in different habitats.
Select all the correct examples of artificial selection.
Broccoli, cauliflower, and kale were created by artificial selection of wild mustard. The different breeds of domesticated dogs have been produced using artificial selection. Darwin raised and developed several breeds of pigeons using artificial selection.
Select all the statements about Charles Darwin that are correct.
Darwin studied similarities and differences among organisms and related them to geological observations. Darwin proposed that natural selection was a force that could change populations and give rise to new species.
flow is the movement of individuals or gametes into or out of a population
Gene
Random mating, a large population, and no mutation, selection, migration, or nonrandom mating are all assumptions of
Hardy-Weinberg equilibrium.
The idea that organisms could change their body form by repeated use of their body parts and that these changes could be passed to the next generation was introduced by
Lamarck.
What publication did Darwin read during his voyage on the HMS Beagle that convinced him of uniformitarianism and the old age of the Earth?
Lyell's Principle of Geology
Select the true statement about mutation and natural selection.
Natural selection acts on existing mutation.
Select observations and inferences that Charles Darwin made in support of natural selection.
Natural selection can change the characteristics of a population over many generations. There is competition among individuals for limited resources. Organisms are varied and some variations are inherited. More individuals are born than can survive to reproduce. Some individuals survive due to their inherited characteristics, making them more likely to reproduce.
Select the correct statement about natural selection.
Natural selection does not have a goal of a perfect organism.
Select the five assumptions of the Hardy-Weinberg equilibrium that must be met to keep allele frequencies from changing.
No natural selection occurs. Mating is random. The population is large. No mutations occur. There is no migration into or out of the population.
Select all of the following that are examples of the bottleneck effect.
North American bison greater prairie chickens
The shortened title of the book that Charles Darwin published in 1859 was
On the Origin of Species.
Whose essay, describing how factors limit human population size, influenced Charles Darwin's ideas about variation and survival among individuals in a population?
Thomas Malthus
What is an example of the founder effect?
a few birds colonizing an isolated island
A gene pool is the collection of all of the genes and alleles of
a population.
Balanced polymorphism means that multiple ____ of a gene persist in a population at more or less constant frequencies indefinitely.
alleles
Broccoli, brussels sprouts, cauliflower, kale, and cabbage come from the wild mustard plant that humans have influenced over hundreds of years. The process that resulted in these five species is
artificial selection.
Because genes do not "know" when to mutate, it follows that bacterial species with a resistance to an antibiotic must have had a mutation ______ exposure to the antibiotic.
before
Charles Darwin consulted John Gould about the birds that he had collected on the Galápagos Islands. Gould identified 13 distinct types of finches based on the birds'
bills.
When a population's size drops rapidly over a short period, resulting in a loss of many alleles that were present in the larger ancestral population, this is referred to as the ____ effect
bottleneck
Genetic drift is a change in allele frequencies that occurs by ______ and, unlike mutations, it tends to eliminate alleles from the population.
chance
What is an example of microevolution?
change in allele frequencies in a population from generation to generation
In sexual dimorphism, one sex is ______ than the other sex.
different in appearance
Selection for dark-winged moths in a population of moths with pigmentation that varies from light to dark is an example of _____ selection.
directional
Selection for one extreme phenotype in a population would be considered a type of natural selection called ______ selection.
directional
When two phenotypic extremes of a trait are being selectively favored, then a natural population is undergoing _______ selection.
disruptive
If a predator is more likely to prey upon fish that are brightest in color, then natural selection in this environment will favor
drabber fish.
One definition of ______ is "changes in traits from generation to generation."
evolution
is defined as a change in allele frequencies in a population over time.
evolution
In a population, each genotype's ______ is the number of individuals with that genotype, divided by the total size of the ______.
frequency; population
The bottleneck effect is an example of what mechanism of evolution?
genetic drift
Which of the following are mechanisms of evolution?
genetic drift and nonrandom mating
A change in allele frequencies that occurs by chance and that tends to eliminate alleles in a population rather than increase diversity is called
genetic drift.
In the Hardy-Weinberg equilibrium, the terms p2, 2pq, and q2 refer to
genotype frequencies in a population.
In a population undergoing stabilizing selection, what phenotype becomes more common over time?
intermediate
Select all of the following that are examples of sexual dimorphism.
large size and snout of male elephant seals compared to female elephant seals antlers on male deer females that look drab compared to males with showing feathers
In order for natural selection to take place, natural resources, like food and water, must be
limited.
Fossils present in ______ layers of rock are older.
lower
The principle of superposition explains the idea that ______ layers of rock, along with the fossils they contain, are older than the layers ______ them.
lower; above
Select all of the following that occur in natural populations and that violate the assumptions of the Hardy-Weinberg equilibrium.
migration among populations occurs mating is often nonrandom allele frequencies can change due to chance events
A ____is a change in an organism's DNA sequence and is the raw material for evolution, because genes affect phenotypes and evolution acts on phenotypes.
mutation
A(n)____ is a change in a DNA sequence that occurs at random.
mutation
In real populations, what mechanism introduces new alleles into the gene pool and violates the assumptions of Hardy-Weinberg equilibrium?
mutation
The only way that new genetic variants arise is through ______, which is the raw material of evolution.
mutation
What mechanism of evolution introduces new alleles into a population?
mutation
Select all of the following that are mechanisms of evolution and that can alter allele frequencies.
mutation natural selection gene flow
Select the example of a mutation that could result in evolutionary change.
mutation in the chromosome structure of an egg cell before fertilization
New alleles that might allow a bacterium to become resistant to an antibiotic arise through
mutation.
Charles Darwin's book titled On the Origin of Species proposed ______ as an evolutionary mechanism.
natural selection
What occurs when environmental factors cause the differential reproductive success of individuals with particular genotypes?
natural selection
Natural selection can act to eliminate
nonadaptive phenotypes.
Select all of the following that are true about natural selection.
occurs due to variation in environmental factors reproductive success of individuals differs
After reading Malthus's essay, Darwin realized that
poorly adapted individuals would not survive if resources were limited.
Evolution can be defined as a change in allele frequencies within a(n)
population.
A type of natural selection that results from variations in the ability to obtain mates is referred to as
sexual selection.
Species have undergone convergent evolution if they
share characteristics and evolved in similar environments.
Cuvier thought that lower layers of rock were older than those above them. This principle describes
superposition.
The drastic reduction in cheetah population size in the last 10,000 years and the resulting decrease in genetic diversity is an example of
the bottleneck effect.
One cause of genetic drift is _____, in which a small group of individuals leaves its home population and establishes a new, isolated settlement.
the founder effect
Suppose the migration of a subset of the human population to a new area leads to relatively low genetic diversity in the new population. This is an example of
the founder effect.
Which two of the following was Charles Darwin not able to explain or understand with respect to his ideas on natural selection as a force of evolution?
the source of variation within populations how heritable traits were passed from one generation to the next
In 1859, ______ published his book titled On the Origin of Species that underlies many principles of modern life science.
Charles Darwin
Who was a collector and captain's companion on the five-year voyage of the HMS Beagle?
Charles Darwin
Darwin collected birds from the _______ Islands and took them back to England to study, where John Gould identified 13 species of birds called ______.
Galápagos; finches
Geological processes that occur today also occurred in the past, producing changes to Earth over time. This theory was proposed by ______ and is referred to as ______.
James Hutton; uniformitarianism
Select all the reasonings of Charles Darwin that were influenced by Thomas Malthus's essay.
More individuals are born into a population than the habitat can support. Some individuals in a population are better able to obtain resources than others. There is variation in a population.
Select all the key properties of evolutionary adaptations.
They are heritable. They can confer reproductive success.
A(n) ______ is a feature that provides a selective advantage to an organism because it improves its ability to survive and reproduce.
adaptation
Darwin noted that natural selection occurs because
adaptive traits that are heritable can pass to offspring and increase their survival and reproduction.
The number of copies of an allele divided by the total number of alleles in a population is the
allele frequency.
In the state of Hardy-Weinberg equilibrium, allele frequencies
are not changing.
How does natural selection act to change allele frequencies?
favors phenotypes that increase reproductive success
Disruptive selection is a mechanism of natural selection that
favors two or more extreme phenotypes in a population.
The genetic contribution of an organism to the next generation is referred to as
fitness.
A genotype's ____ is the number of individuals with that genotype, divided by the total size of the population.
frequency
In evolutionary terms, fitness of an organism is defined as an organism's
genetic contribution to the next generation.
What is a mechanism by which harmful alleles can be maintained in a population even though homozygous recessive individuals have greatly reduced fitness?
heterozygote advantage
Although Darwin proposed that natural selection acted on heritable traits, Darwin did not understand
how heritable traits were shuffled and passed on between generations.
In artificial selection, ______ determines the traits that give individuals the greatest reproductive success.
human choice
Changes in allele frequencies in a population or species that occur over a relatively short time rather than millions of years is an example of
microevolution
In the 1930s, scientists unified natural selection and genetics into the
modern evolutionary synthesis.
Darwin reasoned that the variety of finch species found on the Galápagos Islands descended from a common ancestor. He used the phrase "descent with____ " to describe gradual genetic changes from the ancestral type.
modification
When the process of ______ takes place over billions of years, a simple organism can give rise to many different types of species, such that all species are related to each other through evolution.
natural selection
What type of reproduction amplifies genetic variation by shuffling alleles and producing genetically different offspring?
sexual
True or false: The goal of natural selection is to produce perfect organisms.
False
Select all the ideas that were considered fundamental principles in explaining the diversity of life before the late 1800s.
Members of a particular species are identical in form and capacity. Organisms arose by special creation and did not change.
Hardy-Weinberg equilibrium is seldom seen in natural populations because
selection takes place in natural systems.
Artificial selection is also called
selective breeding
For a gene that has only two possible alleles with allele frequencies of p and q, the Hardy-Weinberg equilibrium states that p + q =
1
Interbreeding members of the same species compose a
population