Homework 6 Descent with Modification

Homework #6 Descent with Modification

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Activity: The Voyage of the Beagle: Darwin’s Trip Around the World

Click here to complete this activity.

Then answer the questions.

Part A

Darwin’s thinking while on the Beagle was greatly influenced by his reading of a book written by _____.

ANSWER:

Bishop Ussher

Shakespeare

Wallace

Lyell

Chaucer

Correct

Darwin was greatly influenced by Lyell’s Principles of Geology.

Part B

According to this climatograph, London experiences more precipitation during _____ than during any other month.

ANSWER:

January

June

October

February

July

Correct

Precipitation is greatest in October.

Part C

Which of these is a consequence of uniformitarianism?

ANSWER:

Earth is very old.

Populations evolve.

Populations reproduce faster than their food supply.

A Creator made Earth.

Earth is round, not flat.

Correct

Uniformitarianism holds that geologic processes occur today in much the same way as they did in the past.

Part D

The Argentinean pampas are a type of _____.

ANSWER:

temperate deciduous forest

tropical forest

desert

chaparral

grassland

Correct

The pampas are treeless plains.

Part E

At the fossil site at Punta Alta, Darwin found evidence _____.

ANSWER:

of extinction

that Brazilian flatworms were a type of slug

of divine creation

that extinction does not happen

that the pampas could support large mammals

Correct

At Punta Alta, Darwin found the bones of types of mammals that no longer lived.

Part F

Patagonia is a _____.

ANSWER:

tropical forest

desert

grassland

chaparral

savanna

Correct

Patagonia is a desert.

Part G

His experiences with Fuegians and slavery convinced Darwin that differences among all peoples are primarily _____ differences.

ANSWER:

cultural and genetic

due to height

genetic and height-related

cultural

genetic

Correct

Darwin observed that there is no inborn superiority or inferiority separating different peoples.

Part H

Species in hot climates tend to _____ compared to species in cold climates.

ANSWER:

experience less interspecific competition

be less colorful

have larger surface-to-volume ratios

have smaller surface-to-volume ratios

have less fear of humans

Correct

This makes it easier for these species to cool off.

Part I

In the Andes, at elevations of 12,000 feet, Darwin collected fossilized marine shells. The existence of marine shells at this altitude provided evidence that _____.

ANSWER:

Earth’s surface does not change

marine organisms can survive at great elevation

the deposit had been gradually uplifted to its present location

someone carried them from the oceans and left them on the mountains

geologic processes occur at a rapid rate

Correct

The location where the marine shells were found was once at the bottom of an ocean.

Part J

The Galápagos Islands are located _____.

ANSWER:

off the coast of California

Off the coast of Ecuador

in the Antarctic

off the coast of Brazil

in the Arctic

Correct

The Galápagos Islands are located on the equator off the coast of Ecuador.

Part K

Why were the Galápagos Islands so important to Darwin’s formulation of natural selection?

ANSWER:

The species found on the Galápagos Islands are also found in Australia.

Each island in the Galápagos possessed unique species.

They provided evidence in support of uniformitarianism.

They are where Darwin did most of his writing.

The Galápagos Islands are the only place in the world where finches are found.

Correct

The origin of so many unique species in a small geographical area intrigued Darwin, and played a role in his formulation of natural selection.

Activity: Darwin and the Galapagos Islands

Click here to complete this activity.

Then answer the questions.

Part A

The Galápagos Islands are cooled by the _____.

ANSWER:

Kuroshio Current

Gulf Stream

Humboldt Current

Equatorial Countercurrent

Monsoon Drift

Correct

The Humboldt carries cool water northward from Antarctica.

Part B

How many finch species did Darwin send to the British Museum?

ANSWER:

30

13

21

17

15

Correct

Thirteen distinct species of finch were identified.

Activity: Artificial Selection

Click here to view this animation.

Then answer the questions.

Part A

Which of the following statements about natural selection is true?

Hint 1.

What conditions must be met for natural selection to occur?

ANSWER:

Natural selection favors individuals that reproduce more than others.

Natural selection can be used by farmers to generate organisms with desirable traits.

Natural selection is a process whereby genes are selected randomly for preservation in the next generation.

Natural selection occurs in opposition to evolution.

Correct

Individuals who are better able to survive and reproduce are more likely to be selected for than individuals who don’t survive or cannot reproduce.

Part B

Which term describes a trait that increases an individual’s ability to survive in a particular environment?

Hint 1.

How do individuals change to accommodate their environment?

ANSWER:

Evolution

Fitness

Adaptation

Heritability

Correct

An adaptation is a trait that increases an individual’s ability to survive in a particular environment.

Part C

Which term describes the ability of a trait to be passed on to offspring?

Hint 1.

How do offspring obtain traits from their parents?

ANSWER:

Evolution

Adaptation

Fitness

Heritability

Correct

Heritability is the ability of a trait to be passed on to offspring.

Part D

Which of the following organisms could be produced by artificial selection?

Hint 1.

Remember that artificial selection only works for heritable traits.

ANSWER:

A cow that produces a large quantity of milk.

A dog that serves as the “eyes” for a blind individual.

A rabbit that is housebroken.

A chimpanzee that communicates through sign language.

Correct

A cow’s ability to produce milk is a heritable trait that can be manipulated by artificial selection.

Part E

Which pair of chickens should a farmer breed to produce larger chickens?

Hint 1.

Consider which parental animals have the traits desired in the offspring.

ANSWER:

Small hen, small rooster

Small hen, large rooster

Large hen, large rooster

Large hen, small rooster

Correct

Large parents should be bred to produce larger offspring.

Part F

A farmer wishes to develop a strain of high-yield corn that is also resistant to drought. He has the following individuals from the current year’s crop:

Individual A—Yield: 179 bushels/acre; drought resistance: high

Individual B—Yield: 220 bushels/acre; drought resistance: low

Individual C—Yield: 185 bushels/acre; drought resistance: medium

Individual D—Yield: 140 bushels/acre; drought resistance: high

Individual E—Yield: 200 bushels/acre; drought resistance: medium

Which of the following crosses would produce the highest corn yield with the highest resistance to drought?

Hint 1.

Determine the average yield and drought resistance expected from each cross.

ANSWER:

A and B

C and E

B and B

A and E

Correct

This cross would result in an average corn yield of 189.5 bushels/acre and have a medium-high drought resistance, which is the best you can get for both traits.

Chapter 22 Question 2

Part A

Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier’s attempt to explain the existence of

ANSWER:

uniformitarianism.

evolution.

natural selection.

the fossil record.

the origin of new species.

Correct

Chapter 22 Question 5

Part A

During a study session about evolution, one of your fellow students remarks, “The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.” Which statement is most likely to be helpful in correcting this student’s misconception?

ANSWER:

Disuse of an organ may lead to its eventual disappearance.

Only favorable adaptations have survival value.

Spontaneous mutations can result in the appearance of new traits.

If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation.

Characteristics acquired during an organism’s life are generally not passed on through genes.

Correct

Chapter 22 Question 7

Part A

In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko’s attempts in this regard were most in agreement with the ideas of

ANSWER:

Cuvier.

Lyell.

Darwin.

Hutton.

Lamarck.

Correct

Chapter 22 Question 9

Part A

Which of these conditions should completely prevent the occurrence of evolution in a population over time?

ANSWER:

The environment is changing at a relatively slow rate.

The population lives in a habitat where there are no competing species present.

All phenotypic variation between individuals is due only to environmental factors.

The population size is large.

Correct

Chapter 22 Question 8

Part A

Charles Darwin was the first person to propose

ANSWER:

that population growth can outpace the growth of food resources.

a mechanism for how evolution occurs.

that evolution occurs.

that Earth is older than a few thousand years.

a mechanism for evolution that was supported by evidence.

Correct

Chapter 22 Question 11

Part A

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus?

ANSWER:

Earth changed over the years through a series of catastrophic upheavals.

The environment is responsible for natural selection.

Earth is more than 10,000 years old.

Populations tend to increase at a faster rate than their food supply normally allows.

Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future.

Correct

Chapter 22 Question 19

Part A

The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because

ANSWER:

humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.

humans are becoming resistant to bacteria by taking methicillin.

humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant.

S. aureus is cultivated by humans to replenish the soil with nutrients.

Correct

Activity: Reconstructing Forelimbs

Click here to complete this activity.

Then answer the questions.

Part A

Which of the following is(are) homologous to the bones in this image?

ANSWER:

Correct

The digits of a cat are homologous to those of these whale bones.

Part B

The wing of a bat is homologous to the _____ of a whale.

ANSWER:

flipper

tail

blowhole

rib cage

baleen

Correct

The bones of a bat wing and a whale flipper are homologous.

Chapter 22 Question 24

Part A

If two modern organisms are distantly related in an evolutionary sense, then one should expect that

ANSWER:

they shared a common ancestor relatively recently.

their chromosomes should be very similar.

they should share fewer homologous structures than two more closely related organisms.

they live in very different habitats.

they should be members of the same genus.

Correct

Chapter 22 Question 32

Part A

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?

ANSWER:

analogous; analogous

homologous; analogous

homologous; homologous

analogous; homologous

Correct

Chapter 22 Question 35

Part A

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that

ANSWER:

island forms and mainland forms have identical gene pools.

common environments are inhabited by the same organisms.

the islands were originally part of the continent.

island forms and mainland forms descended from common ancestors.

the island forms and mainland forms are converging.

Correct

Chapter 22 Question 48

Part A

About 13 different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that

arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza).

If the six ground finch species have evolved most recently, then which of these is the most logical prediction?

ANSWER:

They should share fewer anatomical homologies with each other than they share with the tree finches.

They should be limited to the six islands that most recently emerged from the sea.

Their genomes should be more similar to each other than are the genomes of the five tree finch species.

The chances of hybridization between two ground finch species should be less than the chances of hybridization between two tree finch species.

Correct

ABC News Video: Exploring Evolution in the Solomon Islands

Watch the ABC News video (2:18 minutes). Then answer the questions to the right.

Part A

Where are the Solomon Islands located?

ANSWER:

off the southern tip of Florida

off the coast of California

in the South Pacific

in the Mediterranean Sea

Correct

Part B

Scientists studying evolution on the Solomon Islands described which animal as the ‘poster child’ for the biological species concept?

ANSWER:

sea turtle

frog

snake

white-eye bird

Correct

Part C

Based on the video, what can you infer about speciation–the process by which one species splits into two or more species?

ANSWER:

New species typically form as a consequence of new parasites or predators in the environment.

It is rare for new species to form on islands.

Different species are typically very different in appearance, even if they are closely related.

Physical separation of populations is often part of the speciation process.

Correct

Part D

Why did the biologists consider a frog that they found to be a new species?

ANSWER:

It was larger than any known frog.

Its call was unique.

It jumped higher than other known frogs.

Its coloration was different from other known frogs.

Correct

Part E

When Darwin wrote On the Origin of Species, he knew very little about the subject of _____, an essential component of evolutionary theory today.

ANSWER:

botany

zoology

genetics

marine biology

Correct

ABC News Video: Protecting the Galapagos Islands

Watch the ABC News video (2:07 minutes). Then answer the questions below.

Part A

Where are the Galapagos Islands located?

ANSWER:

northeast of Australia along the Great Barrier Reef

near the tip of South Africa

600 miles west of Ecuador, near the equator

in the Mediterranean Sea, as part of the Greek Islands

Correct

Part B

Which of the following sets of animals are likely to be found on the Galapagos Islands?

ANSWER:

tortoises, finches, blue-footed boobies

beaver, snakes, armadillos

frogs, lungfish, mountain goats

ostriches, cougars, porcupines

Correct

Part C

Which species is threatening the natural wildlife on the Galapagos Islands?

ANSWER:

humans

zebra mussels

Asian carp

mountain lions

Correct

Part D

The Galapagos Islands were the first place on Earth to _____.

ANSWER:

suffer the complete extinction of all native species

be declared off-limits to all humans

be declared a world heritage site

be invaded by human-introduced species

Correct

Part E

Tourism on the Galapagos Islands is being restricted by requiring tourists to _____.

ANSWER:

be escorted by trained guides at all times

view the islands only from the water

visit each island in groups of only ten individuals at a time

stay at least 100 feet away from all animals on the islands

Correct

Current Events: A Colorful Way to Watch Evolution in Nebraska’s Sand Dunes (New York Times, 8/8/2011)

Read this New York Times article and then answer the questions.

A Colorful Way to Watch Evolution in Nebraska’s Sand Dunes (New York Times, 8/8/2011)

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Part A

What is unique about deer mice?

ANSWER:

They are the only mice found in one distinct color.

They are the most populous mouse found in North America.

They are the only mice that hibernate.

They are the only mice that reproduce three times per year.

Correct

Part B

For this project, which of the following are scientists studying?

ANSWER:

lab mice

lab and wild mice

wild mice

genetically-engineered mice

Correct

Part C

You wish to research how genetics determine color of deer mice. How many genes should you focus on?

ANSWER:

1

3

5

7

Correct

Part D

The three-spine stickleback typically lacks armor in fresh water. Why?

ANSWER:

To allow for faster growth.

The armor hinders its hunting.

It doesn’t need the protection.

Due to delayed development.

Correct

Part E

Which of the following is true?

ANSWER:

Genotype and phenotype are the same thing.

Genotype determines phenotype.

Phenotype determines genotype.

Genotype and phenotype are not related.

Correct

Misconception Question 108

Part A

Soapberry bugs use needlelike “beaks” to feed on seeds within the fruits of various plants. Bugs feed most successfully when their beak length matches the size of the fruit on which they are feeding. For 25 years, populations of soapberry bugs in central Florida have been feeding on small goldenrain tree fruits that were introduced to the area, rather than on the larger native balloon vine fruits that serve as food for other soapberry bug populations. Beak lengths of soapberry bugs are variable, but the average beak length is shorter in soapberry bug populations that feed on goldenrain tree fruits than in populations that feed on balloon vine fruits, as shown in the graph. How does natural selection act on beak length in soapberry bug populations?

ANSWER:

Natural selection increases beak length in soapberry bug populations.

The action of natural selection on beak length in soapberry bug populations varies with the environment.

Natural selection decreases beak length in soapberry bug populations.

Correct

Traits favored by natural selection may change as the environment in which a population lives changes. Selection and adaptation must always be discussed in the context of a particular environment. Soapberry bugs feed most effectively when their beak length closely matches the size of the seed-containing fruit. In central Florida, where soapberry bugs feed on small goldenrain tree fruits, natural selection has reduced average beak length in the population of bugs. However, in Louisiana, where soapberry bugs feed on larger fruits, natural selection has increased average beak length in the population of bugs.

Misconception Question 109

Part A

What happened in the soapberry bug population in central Florida when the bugs began to feed on smaller goldenrain tree fruits?

ANSWER:

Bugs developed short beaks, because they needed them to feed on the small fruits.

Bugs with shorter beaks had more access to food, allowing them to produce more offspring.

The length of each bug’s beak gradually became shorter over time.

Correct

Bugs that happened to have short beaks were better able to feed on the small fruits. Their increased access to food allowed them to produce more offspring, which also had small beaks. However, bugs with small beaks did not arise in order to feed on the small fruits. Evolutionary change comes about as the proportion of individuals in the population displaying a particular trait increases from generation to generation. The trait does not change gradually in all members of the population.

Chapter 22 Question 5

Part A

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that

ANSWER:

humans and chimpanzees share a relatively recent common ancestor.

humans and chimpanzees are not closely related.

chimpanzees evolved from humans.

convergent evolution led to the DNA similarities.

humans evolved from chimpanzees.

Correct

Chapter 22 Pre-Test Question 1

Part A

Which of the following is an example of the pattern of evolution? (Overview)

Hint 1.

The pattern of evolutionary change is revealed by data.

ANSWER:

natural selection

the fossil record of the evolution of modern cetaceans

the inheritance of acquired characteristics

heredity

descent with modification

Correct

The fossil record contains observable data regarding both the morphological development and biogeographical distribution of early cetaceans.

Evidence for Evolution

Charles Darwin described evolution as “descent with modification,” meaning that species change through time. A great deal of evidence indicates that life has evolved over time and continues to evolve. Natural selection is the primary mechanism by which evolution takes place.

Part A – Scientific evidence supporting evolution

Scientific evidence documents the pattern of evolution. The evidence exists in a variety of categories, including direct observation of evolutionary change,

the fossil record, homology, and biogeography. Sort the following examples into the correct categories.

Drag each phrase to the appropriate bin.

Hint 1. What are the meanings of the terms relating to evidence for evolution?

Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.

ANSWER:

Hint 2. Skeletal structure of mammalian forelimbs

The forelimbs of mammals, regardless of shape or function, have the same arrangement of bones. The most parsimonious explanation (the one that is least complex and requires the fewest evolutionary changes) is that the different forelimbs represent variations of a structure present in a common ancestor. The image below shows the forelimbs of four mammals: human, cat, whale, and bat.

Similar characteristics in different species that result from having a common ancestor are called homologies.

Hint 3. Transitional forms and extinct species

The fossil record shows that present-day organisms differ from past organisms and that many species have become extinct. In addition, fossils can

document evolutionary changes that have occurred in particular groups of organisms through time. For example, the following diagram shows part of the fossil record of horses. Notice that the large present-day horse (Equus), which has a single toe on each foot and teeth adapted for grazing, evolved from a small, many-toed ancestor (Hyracotherium) with teeth adapted for browsing. With the exception of Equus, all of the organisms shown in the diagram are extinct.

ANSWER:

Correct

Scientists have directly observed evolution occurring in many instances, including the development of drug resistance in bacteria and other pathogens. The fossil record has provided evidence for extinct species and for transitional forms of organisms, such as the ancestors of present-day horses. Homologies include similarities in structure, development, and DNA sequences in different organisms. Vestigial structures are homologous structures that have a reduced function or no function at all. Examples include the pelvic bones of whales.

The geographic distribution of species, such as the high concentration of marsupial mammals in Australia, can provide evidence about common ancestors. In addition, the endemic species found on many island chains yield information about evolution on those islands.

Part B – Phylogenetic trees and geographic relationships

The island fox, Urocyon littoralis, is endemic to the Channel Islands, which are located off the coast of southern California. Six of the eight Channel Islands support fox populations, and each of these islands is home to a distinct subspecies, as shown in the table below.

The island fox shares a common ancestor with the gray fox, Urocyon cinereoargenteus, which is found on the mainland. Both species have similar coloration and a diploid chromosome number of 66. One structural difference between the two species is the reduced size of the island fox, a feature known as dwarfism. The various island subspecies also differ from each other in size, number of tail vertebrae, and other characteristics.

The phylogenetic tree below shows the evolutionary relationships between the island fox subspecies and the gray fox. Drag the labels to their appropriate locations on the tree.

First, drag the blue labels onto the blue targets to identify the common ancestors at the branch points.

Next, drag one white label onto the white target to identify the homologous characteristic.

Then, drag one pink label onto the pink target to identify the relationship between the two species.

Hint 1. How to read a phylogenetic tree

A phylogenetic tree is a diagram that reflects evolutionary relationships among groups of organisms. Each branch point in the tree represents the common ancestor of the lineages beginning at that point or to the right of it. In the tree below, branch point 1 represents the common ancestor of species A, B, and C, whereas branch point 2 represents the common ancestor of species B and C.

A hatch mark in a phylogenetic tree represents a homologous characteristic shared by all the groups to the right of the mark. In this example, the hatch mark indicates a homologous characteristic shared by species B and C; that characteristic is not found in species A.

In the tree below, species B and C are more closely related than species A and B because they share the more recent common ancestor.

Hint 2. How can you determine the relatedness of species on a phylogenetic tree?

Based on the information in the tree below, rank the given pairs of species from most closely related to least closely related.

Rank the pairs from most closely related to least closely related.

ANSWER:

Hint 3. Can you place homologous characteristics on a phylogenetic tree?

The following table lists characters of five imaginary animal species. A check-mark (√) indicates the presence of a character, and a dash ( ) indicates the absence of a character.

Characters

Add the characters to the appropriate places on the phylogenetic tree shown below. Drag the labels onto the phylogenetic tree. ANSWER:

ANSWER:

Correct

One notable difference between gray foxes and island foxes is the small size of island foxes. This character (dwarfism) was exhibited by the common ancestor of all six island fox subspecies. Note that the northern Channel Island fox subspecies are more closely related to each other than to any of the southern subspecies, and that the southern subspecies are more closely related to each other than to the northern subspecies.

Part C – Natural selection in monkey flowers

Some monkey flowers (Mimulus guttatus) living near the sites of copper mines can grow in soil containing high concentrations of copper, which is toxic to most plants. Copper tolerance is a heritable trait.

The map below shows the area near an old copper mine, which contaminated the nearby soil with copper. A stream flows past the mine toward the lake at the bottom right of the map.

Use the map to determine which of the statements below are true.

Select the three statements that are true.

Hint 1. Process of natural selection

Natural selection includes the following main ideas:

Individuals within a population vary.

Much of the variation is due to heritable traits.

In any given environment, some heritable traits give individuals a higher probability of surviving and reproducing.

Individuals that have such traits tend to leave more offspring than other individuals.

Therefore, the frequency of favorable traits increases in the population over generations.

Hint 2. Can you outline the steps in natural selection in another example?

The increased frequency of copper tolerance in monkey flowers can be compared to the increased frequency of drug resistance in bacteria. What are the steps leading to drug resistance in a population of bacteria?

Drag the labels to their appropriate labels on the flowchart.

ANSWER:

ANSWER:

Natural selection favors copper tolerance in all soils near the old mine, not only in the contaminated soils.

If you were to test monkey flowers growing on the shore of the lake, you would expect nearly 100% of them to be copper tolerant.

The population that existed before mining must have included both copper-tolerant and copper-intolerant plants.

Copper-tolerant plants are found only in contaminated soils.

Copper contamination in the soil created copper-tolerant plants.

Nearly 100% of monkey flowers growing in copper-contaminated soil are copper tolerant.

Correct

Copper tolerance in monkey flowers is an example of a direct observation of evolution. Natural selection favors the survival and reproduction of copper-tolerant plants in copper-contaminated soils. Therefore, the allele for copper tolerance must have been present in some plants when the soil became contaminated. Because copper tolerance provides no benefit to plants in uncontaminated soils, the trait is not as common in plant populations growing outside the contaminated area.

Score Summary:

Your score on this assignment is 89.9%.

You received 20.68 out of a possible total of 23 points.