Biology chapter 11
Biologic evolution changes individual organisms.
False
The theory of evolution attempts to explain the origin of life.
False
Imagine the formation of a new mountain range that splits a population of flowering plants into two populations, one on either side of the mountains. This would be an example of vicariance.
True
The model of speciation that requires some time with geographic barriers between two populations, allowing evolution of reproductive isolation, is
allopatric speciation.
A variety of genotypes and phenotypes in a population is useful because it
allows the species to survive if the environment changes.
Structures that are similar in function and appearance but do not share an origin in a common ancestor are referred to as ___.
analogous
When two species evolve in different directions from a common point, it is called ___.
divergent evolution
The gene pool of a population of bighorn sheep in the southwest United States is altered when several sheep cross over a mountain pass and join the population. This would be an example of ___.
gene flow
Movement of alleles between populations such as by the migration of breeding individuals is called
gene flow.
A random alteration in the sequence of DNA nucleotides that provides a new variant of the gene is
gene mutation
The ________ is the total number of alleles of all the gene loci in all the members of a population.
gene pool
If there is a change in the allele frequency of a gene pool due to chance, primarily in a small population, it is termed
genetic drift
Which of the following mechanisms does NOT result in variation in the gene frequencies from the ancestral population?
genetic equilibrium
Which of the following would NOT be a cause of sympatric speciation?
geographic separation
The wing of a bird and the arm of a human are examples of ___ structures.
homologous
Population genetics is the study of ___.
how allele frequencies in a population change over time
Inbreeding (mating between relatives to a greater extent than by chance) within a population is an example of
nonrandom mating
What is the correct order of the steps regarding allopatric speciation?
one species → geographic isolation → reproductive isolation → two species
All the members of a single species that occupy a particular area and are able to interbreed are a
population
Allopatric speciation requires a geographic barrier to block gene flow; sympatric speciation does not.
True
According to Lamarck, which variable would have the greatest influence on the evolution of an organism?
the environment
In order for natural selection to occur, which of the following is NOT needed?
Populations must be geographically isolated from one another
Which piece of evidence did Darwin observe during his 5-year journey aboard the HMS Beagle?
A South American species of finch is most likely the ancestor of the Galápagos Island finches.
According to the Hardy-Weinberg equilibrium, in a population in which 1% does NOT have freckles (recessive), what percentage of the next population is likely to NOT have freckles?
1%
Which situation would most likely lead to allopatric speciation?
A flood causes the formation of a new lake
Natural selection, which is the mechanism of evolution, was independently described by Charles Darwin and ___.
Alfred Russell Wallace
Which of the following would NOT upset Hardy-Weinberg equilibrium?
All individuals in a population having the same chance at reproducing
According to the evolutionary theory, which statement is NOT true?
All living things are NOT descended from a common ancestor.
Which of the following situations will lead to natural selection?
All of the above
___ starts with related species that look very similar but are faced with different ecological problems. Over time, their body parts become modified differently to fit their own set of conditions. The result is related organisms that have different morphologies.
Divergent evolution
Among biologists, the theory of evolution is still controversial.
False
All mutations either increase or decrease the fitness of an organism.
False
Which of the following is true about genetic drift?
It may lead to an allele becoming fixed in a population when its alternative allele is lost from the population
___ is a change in the allele frequencies of a population over time.
Microevolution
What is the difference between micro- and macroevolution?
Microevolution describes the evolution of populations, while macroevolution describes the emergence of new species over long periods of time.
Which of the following is true about natural selection?
On average, it favors the survival of young with adaptive characteristics.
What is the main difference between dispersal and vicariance?
One involves the movement of the organism, whereas the other involves a change in the environment
Which of the following would NOT result in reproductive isolation?
Snakes found in one state are genetically identical to snakes found in a neighboring state with no geographic barriers separating them.
Which statement is NOT true about the founder effect?
The founder effect occurs when a population is subjected to near extinction and then recovers, so that only a few alleles are left in survivors.
When he arrived at the Galápagos Islands, Darwin did not observe the amazing tool-using "woodpecker finch" that can modify twigs to pry out grubs. Because there are no true woodpeckers on the Galápagos Islands, this behavior allows this finch to exploit an untapped food source. However, not all members of this species exhibit this behavior, which is probably learned from watching other finches. Therefore, which of the following is NOT true?
This "learned" behavior will not lead to evolutionary change in the woodpecker population.
The observation by ________ that human reproductive potential would rapidly outstrip available food and living space was an important concept adopted by Darwin in formulating his theory of natural selection.
Thomas Malthus
The northern elephant seal went through a severe population decline as a result of overhunting in the late 1800s. As a result of a hunting ban, the population has rebounded but is now homozygous for nearly every gene studied. This would be an example of ___.
a bottleneck
When only a few individuals survive unfavorable times, thereby losing the majority of genotypes in the next generation, it is called
a bottleneck effect
During allopatric speciation
a geographic separation occurs between subpopulations.
The Hawaii archipelago was originally colonized by just a single species of honeycreeper (a type of bird). Over time, this species underwent many changes to occupy empty ecological niches and there are now many species. This is an example of ___.
adaptive radiation
Which of the following can be used to investigate the accumulation of small changes in the gene pool of a population over time?
basic biochemical molecules that are universal.
If two adjacent populations of the same species show gene flow, then the two populations will
become more similar in their gene pools
A line of evidence NOT considered by Darwin in his development of the theory of natural selection is
biochemistry (= molecular biology)
Homologous structures such as the bones in wings, flippers, and arms are most closely concerned with
comparative anatomy
Unrelated species that have similar morphology (= physical shapes) can be explained by ___.
convergent evolution
The fact that DNA sequences are more similar in more closely related organisms is evidence of what?
descent with modification
What is the unifying theory in biology that explains the relationships of all living things?
evolution
The word "theory" in theory of evolution is best replaced by ___.
fact
A scientific theory is an idea proposed by someone but which does not have any evidence supporting it.
false
The organisms examined by Darwin on the Galápagos Islands that were most important in his development of the theory of natural selection were
finches
Which evidence for evolution uses impressions of plants and animals pressed into sedimentary rock?
fossil record
Galápagos medium ground finches are found on Santa Cruz and San Cristóbal islands, which are separated by about 100 km of ocean. Occasionally, individuals from either island fly to the other island to stay. This can alter the allele frequencies of the population through which of the following mechanisms?
gene flow
Which variable increases the likelihood of allopatric speciation taking place more quickly?
longer distance between divided groups
What is the term used to describe the accumulation of small changes in the allele frequencies of a gene pool of a species over time?
microevolution
The raw material for evolutionary change is
mutation
In which of the following pairs do both evolutionary processes introduce new genetic variation into a population?
mutation and gene flow
Which of the following agents of evolutionary change results in adaptation?
natural selection
Within a population, plants that produce a toxin that kills plant-eating insects are more likely to survive and reproduce than plants that do not produce the toxin. This would be an example of ___.
natural selection
If the Hardy-Weinberg equilibrium is met, what is the net effect?
no evolution because the alleles in the population remain the same
A study in Jordan examined the allele frequencies in the ABO blood system. The frequency of any one of the alleles is the number of copies of that allele divided by all the copies of the ABO gene in the population. The study found a frequency of IA to be 26.1 percent. The IB and I0 alleles made up 13.4 percent and 60.5 percent of the alleles respectively, and all of the frequencies add up to 100 percent. This would be an example of the use of ___
population genetics
During sympatric speciation
reproductive isolation between certain subpopulations occurs.
Which of these conditions is NOT among the requirements of the Hardy-Weinberg equilibrium?
small population with genetic drift
Africa, Asia, South America, and Antarctica share some patterns of primitive (fossil) plants and early reptiles, but do not have similar mammal populations. This therefore
suggests that the earlier plants and reptiles evolved while continents were joined but mammals radiated into diverse groups after separation.
A small, reproductively isolated religious sect called the Dunkers was established by 27 families that came to the United States from Germany over 200 years ago. The frequencies for blood group alleles in this population differ significantly from those in the general U.S. population. This would be an example of ___.
the founder effect
What evidence would NOT be studied by a biogeographer?
the genetic makeup of organisms that evolved in separate but similar conditions
___ describes how evolutionary pressures, such as natural selection, can affect a population's genetic makeup, and, in turn, how this can result in the gradual evolution of populations and species.
the modern synthesis
In order for natural selection to occur, a population must exhibit variation at the genetic level.
true
Which of the following conditions does NOT contribute to evolution?
unchanging environmental conditions
Anatomical features that are fully developed and functional in one group of organisms but reduced and functionless in a similar group are termed
vestigial
Structures that once had a purpose but no longer serve any function in an organism are termed ___.
vestigial
An insect population lives along the edge of a north-south mountain range. The populations from the east and west slope eventually join in a low northern pass and interbreed, producing fertile offspring; but they do not circle around the southern edge because of a desert barrier. When glaciers move southward, the populations are pushed south of the northern pass and are isolated. While isolated, the two populations develop enough differences over time that when the glaciers retreat north and the insects again share the same pass, they no longer mate at the same time, nor can they produce fertile offspring. These insects
were originally one species but are now two species