Biology: Chapter Eleven

True or False: All mutations either increase or decrease the fitness of an organism.

False

True or False: The theory of evolution attempts to explain the origin of life.

False

True or False: Among biologists, the theory of evolution is still controversial.

False.

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

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

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.

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

The word "theory" in theory of evolution is best replaced by __

fact

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%

The five conditions that must be met for Hardy-Weinberg Equilibrium to be met are;

1) no mutation 2) random mating 3) an infinitely large population 4) a population that is reproductively isolated from other populations of the same species 5) all phenotypes must be equally able to survive and reproduce.

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.

Which situation would most likely lead to allopatric speciation? An injury causes an organism to seek out a new food source. A storm causes several large trees to fall down. A mutation causes a new trait to develop. A flood causes the formation of a new lake.

A flood causes the formation of a new lake.

Macroevolution

New species over time.

Which of the following would NOT upset Hardy-Weinberg equilibrium? All individuals in a population having the same chance at reproducing Mutations producing new alleles Individuals moving in and out of a population Changes in allele frequencies due to chance, random events

All individuals in a population having the same chance at reproducing

According to the evolutionary theory, which statement is NOT true? Evolution explains the diversity of life. Diversity occurs because various living things are adapted to different ways of life. Evolution explains the unity of life. All living things share the same fundamental characteristics. All living things are NOT descended from a common ancestor.

All living things are NOT descended from a common ancestor.

Which of the following situations will lead to natural selection? The seeds of two plants land near each other and one grows larger than the other. Two types of fish eat the same kind of food, and one is better able to gather food than the other. Male lions compete for the right to mate with females, with only one possible winner. All of the above.

All of the above.

In the case of Darwin's finches, an ancestral finch species from the mainland arrived on the Galápagos Islands and soon developed into many new species via adaptive radiation. The finches did NOT undergo adaptive radiation back on the mainland. What is the most plausible biological explanation?

Competition from many other bird species on the mainland that was absent on the islands.

___ 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

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. It increases the level of rare alleles in a population. It reduces the chances of mutation in a population. It increases the number of heterozygotes in a population. It is more likely to occur in a large population than in a small population.

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.

In order for natural selection to occur, which of the following is NOT needed? Traits in a population must vary between individuals. Populations must be geographically isolated from one another. Traits must have a genetic basis and so are passed on to offspring. Some traits must allow the individual to survive and/or reproduce better than others.

Populations must be geographically isolated from one another.

Which of the following would NOT result in reproductive isolation? Fruit flies on one Hawaiian island live for hundreds of generations and do not come in contact with fruit flies on another island except when blown there by rare tropical storms. Snakes found in one state are genetically identical to snakes found in a neighboring state with no geographic barriers separating them. One brood of the 17-year cicada emerged in 1987 (and will do so every 17 years) and lives a few months as adults; another brood emerged in 1992 (and will do so every 17 years); the larvae of both feed side by side on tree roots. A lion and a tiger mate in the artificial confines of a zoo but the offspring is infertile. Two populations of crickets are indistinguishable in physical features but the females in each group only come to the different songs of their males.

Snakes found in one state are genetically identical to snakes found in a neighboring state with no geographic barriers separating them. Reproductive isolation would not result from having genetically identical populations spread out over a wide range. As long as the populations are experiencing gene flow reproductive isolation would not be possible.

Microevolution

The evolution of populations/a change in the allele frequencies of a population over time.

allopatric speciation

The formation of new species in populations that are geographically isolated from one another.

sympatric speciation

The formation of new species in populations that live in the same geographic area

Which statement is NOT true about the founder effect? It is a form of genetic drift. It produces a high frequency of some rare alleles in a small isolated population. Founding members contain a tiny fraction of the alleles found in the original population. Chance determines which alleles are carried by the original founders. 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.

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.

___ 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

___ 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

Which is NOT one of the preconditions in a population where natural selection is at work? There is variation that can be inherited in a population. Adaptive characteristics in some individuals make them more likely to survive and reproduce. Heritable variations must be passed on the subsequent generations. Many more individuals are produced by a population than can survive and reproduce. The population always becomes adapted to its environment.

The population always becomes adapted to its environment.

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.

True or False: Allopatric speciation requires a geographic barrier to block gene flow; sympatric speciation does not.

True

True or 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

True or False: In order for natural selection to occur, a population must exhibit variation at the genetic level.

True.

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.

Which of the following would NOT be an example of sexual selection? a zebra stallion chasing away smaller, weaker males so that controls the territory with the best food and water female peacocks preferring males with the largest, most colorful tails female robins mating with the male who sings the "prettiest" song a female frog who produces more eggs that other females

a female frog who produces more eggs that other females

The Amish of Lancaster, PA. have a higher frequency of an unusual form of dwarfism than the population at large. This is probably due to

a founder effect.

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

The model of speciation that requires some time with geographic barriers between two populations, allowing evolution of reproductive isolation, is

allopatric speciation.

Structures that are similar in function and appearance but do not share an origin in a common ancestor are referred to as ___.

analogous

Which of the following can be used to investigate the accumulation of small changes in the gene pool of a population over time? structural proteins. basic biochemical molecules that are universal. similarities only based on available dietary proteins. blood type molecules. There are no restrictions, any amino acids for any structure would provide a legitimate comparison among organisms.

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.

The fact that DNA sequences are more similar in more closely related organisms is evidence of what?

descent with modification

Which variable increases the likelihood of allopatric speciation taking place more quickly? equivalent numbers of individuals in each population longer distance between divided groups lower rate of mutation increased instances of hybrid formation

longer distance between divided groups

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.

In which of the following pairs do both evolutionary processes introduce new genetic variation into a population? natural selection and genetic drift mutation and gene flow natural selection and gene flow gene flow and genetic drift

mutation and gene flow

Which of the following agents of evolutionary change results in adaptation? gene flow genetic drift mutation nonrandom mating natural selection

natural selection

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

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 I A 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

All the members of a single species that occupy a particular area and are able to interbreed are a

population.

Which of these conditions is NOT among the requirements of the Hardy-Weinberg equilibrium? no selection of one genotype over another no net migration of alleles into or out of the population no net mutations small population with genetic drift sexually reproducing and random mating population

small population with genetic drift.

According to Lamarck, which variable would have the greatest influence on the evolution of an organism?

the environment

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

Structures that once had a purpose but no longer serve any function in an organism are termed ___.

vestigial