Chapter 11 - Where Did We Come From?

When did life first appear on the planet?

3.5 billion years ago

How old is our planet Earth?

4.6 billion years old

You have a housecat. Which of the following would likely work the best for your cat?

A brush that penetrates her fur and reaches the skin.

In studying a species of fish, a structure is discovered that has no apparent function. If this is a vestigial structure, what should be found in some relatives of this fish?

A similar structure should be present, but it would be larger and have a function.

How are adaptations beneficial to organisms?

Adaptations help organisms survive and reproduce in a particular environment.

Which scientist also proposed a mechanism for evolution similar to natural selection?

Alfred Russel Wallace

Which of the following is evidence for evolution in action?

All are evidence for evolution

Which of the following is true?

All housecats have the same size tongue papillae.

What is an adaptation?

All of the above are correct

Who was Charles Darwin?

An English naturalist who traveled the world in the early 19th century

What type of statement would most biologists consider the statement "All modern organisms derive from a single common ancestor" to be?

An accepted scientific theory

Cauliflower, broccoli, Brussels sprouts, cabbage, and kohlrabi are all the same species of plant. What is responsible for the differences in these vegetables?

Artificial selection

Which explanation could be considered a Lamarckian argument?

As giraffes stretched their necks to eat leaves, a long neck trait was passed to their offspring and subsequent generations.

Which example describes microevolution?

Beetles evolved resistance to chemical pesticides.

Why would the DNA of cats and dogs be more similar than the DNA of cats and hamsters?

Cats and dogs have a more recent common ancestor than cats and hamsters.

Which of the following best defines microevolution?

Changes in genes within a population over time

Which organisms are most closely related?

Cheetahs and leopards, which are both in the family Felidae

What does the presence of a tail in early human embryos and other chordates suggest about all chordates?

Chordates were derived from a common ancestor with this developmental pathway.

Humans and chimpanzees have a common ancestor that lived approximately 5 million years ago. Scientists have arranged an impressive collection of ancestral human fossils in chronological order to observe the evolutionary changes to more human-like characteristics. What evidence supports the statement that humans and chimps have a common ancestor that lived approximately 5 million years ago?

DNA sequence similarity

Which fact best supports the hypothesis of one common ancestor for all life?

DNA sequences from bacteria can be transferred to plants and other organisms.

What type of evolutionary evidence would include the pharyngeal slits in chordates?

Developmental homology

Which option best describes the concept of an evolutionary tree diagram?

Evolutionary trees relate species to each other by ancestry. An ancestor common to all of the species is placed at the root of the tree. Branch points are defined by homologous features that are shared by the descendant species along a particular branch.

How do genetic engineering techniques lend support to the theory of common descent?

Genes from one organism can be moved to a very different organism and still code for the same protein.

Which of the following processes is most likely to occur on this small population of humans?

Genetic drift

The Carolina chickadee, boreal chickadee, and black-capped chickadee are small songbirds that look and sound very similar to one another. What could account for their differences?

Geographical separation

What was Lamarck's idea about how organisms changed?

He proposed that body parts changed as a result of extra use or disuse.

How did the geologist Charles Lyell influence Darwin?

He suggested that slow, gradual changes shaped the features of Earth.

Your friend wants a cat but doesn't want to brush it. Which of the following is true?

He would do well to avoid getting a long-haired ragdoll.

Human embryos have a developmental stage during which they have a tail and pharyngeal pouches (those pouches develop into gills in fish). How can we explain these characteristics of human embryos?

Human embryos share a common ancestor who had gills.

How might global warming result in most grizzly bears having fur that is less dense in the future?

In any population of bears, some individuals have thick fur, some have thin fur, and some are in between. As temperatures increase with the passage of time, the survival of bears with thin fur will increase, and the number of bears in the population with thick fur will decrease.

Which change is an example of biological evolution?

Methicillin-resistant Staphylococcus aureus is resistant to many antibiotics.

Why can evolution in mosquitoes be more easily observed than evolution in a population of squirrels?

Mosquitoes have a shorter generation time.

Before Darwin published his work, Lamarck and others had suggested mechanisms for evolution. By what means did Darwin propose species evolved over time?

Natural selection

What process involves populations adapting to a changing environment?

Natural selection

Which of the following statements regarding natural selection is false?

Natural selection starts with the creation of new alleles that are directed toward improving an organism's fitness.

The tree diagram below shows the evolutionary relationships among several primates. What information can be inferred according to the diagram?

Orangutans are less closely related to bonobos than to gorillas.

Which two observations led Darwin to conclude that there is competition for survival?

Overproduction of organisms and limited food resources

Why is common descent considered a scientific theory?

Overwhelming evidence supports it from many areas of biology.

Which human structure has a modification that allows for an upright stance?

Pelvis

Why do organisms with different appearances develop along similar pathways?

Similar genes control the development of these organisms.

What conclusion resulted from Darwin's observations on the voyage of the HMS Beagle?

Similar species share a common ancestor.

Why would intelligent design not be considered a scientific explanation for the origin of living things?

Supernatural causes cannot be tested with experiments.

Before the publication of Charles Darwin's On the Origin of Species, what was the prevailing public consensus regarding species evolution?

That species were permanent and unchanging

According to this phylogenetic tree, which bear is most closely related to the American black bear?

The Asiatic black bear

What evidence shows the similarities between humans and apes?.

The DNA, development, and adult anatomy

Why are bat wings homologous to the front legs of cats?

The common ancestor of bats and cats contained a similar bone structure.

The forelimbs of humans, cats, and bats have a number of detailed similarities in their construction. What best explains these similarities?

The forelimbs are similar because all of these organisms inherited the basic forelimb design from a common ancestor.

What is biological evolution?

The gene changes occurring in populations over many generations.

What geographic conditions of the Galápagos Islands affected the diversity of organisms observed by Darwin?

The islands are oceanic.

A pharmaceutical company is developing a new head lice treatment that kills 99% of lice on contact. What may happen after the treatment has been used for a few years?

The number of lice resistant to the chemical treatment will increase.

Which factor would be the most important consideration for a scientist designing a study to observe evolution in a population?

The organism should have a short generation time.

Which of the following statement is correct regarding the phylogenetic tree above?

The polar bear and the brown bear are the most recently evolved species.

Consider a hypothetical insect population of 100 individuals. Two equally represented alleles (A and a) exist for a particular gene. Which scenario is an example of microevolution in this population?

The population is exposed to a toxin that kills individuals with the A allele. After exposure to the toxin the population has 25 surviving individuals, and 95% of them have the aa genotype.

A population of small fish lives in a lake with a sandy bottom. The major predator of these fish is a wading bird that hunts by sight. Most of the fish are light sandy brown, but about 10% are mottled. The color pattern is heritable. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction?

The proportion of mottled fish will increase over time.

A zombie apocalypse wipes out almost the entire human species before the zombie threat is eliminated. Only a group of 100 people who were at a family reunion on an uninhabited island survived. They returned to the mainland completely unaware of what had happened to everyone. Answer the following question(s) regarding the few survivors who now begin to rebuild the human population. Despite an abundance of habitat, why will it be difficult for the human species to recover?

The reduced genetic diversity will make it difficult for the population to adapt to new diseases or other environmental changes.

From the perspective of an evolutionary biologist, what significant information can be inferred from this figure?

The relative arrangement of bones is similar.

What characteristics would determine whether structures from two kinds of organisms are homologous?

The structures should have similar anatomy in the two organisms.

A dog breeder wishes to develop a breed that does not bark. She starts with a diverse mixture of dogs. Generation after generation, she allows only the quietest dogs to breed. After 30 years of work she has a new breed of dog with interesting traits, but on average, the dogs still bark at about the same rate as other dog breeds. Which of the following would be a logical explanation for her failure?

The tendency to bark is not a heritable trait.

Which of the following is true of homologous structures?

They are structurally similar due to inheritance from a common ancestor.

Your aunt conducts research on ocelots in Central America. Which of the following is true of her research subjects?

They have papillae on their tongues.

According to the theory of common descent, how should each species on Earth today compare?

They should have a single ancestor in common.

What prompted Darwin to publish his book decades after he began writing it?

Wallace, a colleague, was about to publish a similar manuscript.

Which description would be considered a scientific theory like the theory of evolution?

a theory about why an apple falls to the ground when dropped

Whales have a small pelvic girdle similar to the pelvic girdle of land mammals connecting leg bones to the skeleton. What evidence for common descent would include the whale's pelvic girdle?

a vestigial structure

Evolution can be best defined as ________.

change in the gene pool of a population

Comparing the body structures of organisms to find evidence of a shared evolutionary history is called ________.

comparative anatomy

Which species is most likely to share the greatest percentage of DNA with humans?

deer

The core theme of biology, which explains both the unity and diversity of life, is

evolution

Which taxonomic level would contain members that are the most similar?

genus

Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species; both species have four limbs with a similar skeletal structure; the species' early embryos are very similar; and where the salamander has a functional tail, humans have a vestigial tailbone. In evolutionary terms, these are examples of

homology

Natural selection acts on ________, and ________ evolve.

individuals; populations

A weed that exhibits resistance to an herbicide ________.

inherited the gene that made it resistant to the herbicide

The original source of all genetic variation is _____.

mutation

The ultimate source of all new alleles is

mutation

Organisms that possess homologous structures probably __________.

share a common ancestor that also had this structure

What information would be most useful for studying the evolution of a worm species?

similarities in histone genes between other worms and the studied worm

You invent a new cat brush that mimics a cat's tongue. Which of the following liquids does your brush contain?

synthetic cat saliva

Which vestigial structure found in humans shows evolutionary connections to other primates and mammals?

tailbone

In artificial selection, humans provide the selective pressure for species to change and shape the evolution of various breeds. What provides the selective pressure in natural selection?

the environment

What is the molecular clock?

the rate at which mutations accumulate in DNA within a species

Which observation was most influential to Charles Darwin?

the slight differences between organisms on nearby islands

Which of the following represents a pair of homologous structures?

the wing of a bat and the flipper of a whale

If two organisms of different species share more similar DNA sequences with each other than with other species, we can conclude that ________.

these two species are very closely related

If whales evolved from land-dwelling mammals, one would expect the fossil record to include intermediate forms, creatures more whale-like than land-dwelling mammals yet still possessing hind limbs and a pelvis lacking in modern whales. Such intermediates are termed __________.

transitional forms

What type of evidence for the theory of common descent would include the presence of goose bumps in humans?

vestigial structures

Whereas some modern whales possess a small and useless __________ pelvis, __________ linking modern whales to their four-legged evolutionary ancestors possess a larger and even functional pelvis.

vestigial; transitional forms