BIOL 1308 Exam 4

Imagine that individuals with a certain allele (B) have much greater reproductive success than those without the allele. However, individuals with the B allele also have shorter life spans than those without the allele. How would you predict the allele frequencies in the population will change through subsequent generations?

The B allele will become more common only if the individuals reach reproductive ages.

Paleontology is the study of

fossil remains of past life on Earth.

Remains, evidence, or impressions of organisms more than 10,000 years old are called

fossils

a genotype's ________ is the number of individuals with that genotype, divided by the total size of the population.

frequency

In a population, each genotype's ______ is the number of individuals with that genotype, divided by the total size of the ______.

frequency; population

Analogous structures have similar ______ but do not have a common developmental pathway.

functions

_______ flow is the movement of individuals or gametes into or out of a population.

gene

The spread of plant pollen by wind for several miles to a new population is an example of

gene flow.

In evolutionary terms, fitness of an organism is defined as an organism's

genetic contribution to the next generation.

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

The bottleneck effect and the founder effect are two types of

genetic drift

Which of the following are mechanisms of evolution?

genetic drift and nonrandom mating

Ernest Mayr proposed that the definition of biological species should be a population whose members

can interbreed and produce fertile offspring.

Genetic drift is a change in allele frequencies that occurs by ______ and, unlike mutations, it tends to eliminate alleles from the population.

chance

Extinctions occur when

no member of a species has the alleles necessary to survive and reproduce when conditions change.

Natural selection can act to eliminate

nonadaptive phenotypes

Experiments conducted by Conover and Munch at Stony Brook University indicate that harvesting of large fish is acting as a selective force to

decrease average fish size in the population.

The graph shows that when large fish are harvested from experimental tanks, the average weight of individuals ______ over subsequent generations, and the growth rate of these fish is ______.

decreases; slower

Gradual genetic changes in organisms from an ancestral species describes

descent with modification

The similar structures in vertebrate embryos shows that ______ can reveal homologous structures and evolutionary relationships.

development

In sexual dimorphism, one sex is ______ than the other sex.

different in appearance

In adaptive radiation, a species ______ in response to new conditions and lack of competitors.

diversifies into many new species

The exact match in amino acid sequences of proteins found in closely related species is an example of how comparisons of ______ can indicate evolutionary relationships.

proteins

According to the chart, what organism shared the most recent common ancestor with humans?

rabbit

______ dating places fossils into a sequence of events without assigning a specific age.

relative

What kind of fossil dating places fossils into a sequence from oldest to most recent but doesn't assign a specific age to the fossils?

relative dating

In comparing nucleotide or amino acid sequences, researchers base evolutionary relationships on the assumption that

the more closely related two species are, the greater the similarity in their DNA and proteins.

What phrase describes macroevolution?

the process of new species appearing and other species going extinct on Earth over long periods of time

Structures are called homologous if

the similarities between them reflect common ancestry.

Bacteria, Archaea, and Eukarya are the names of the three ______ of life.

domains

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.

Biogeography is the study of

the distribution of species across Earth.

Anatomical structures that have similar functions but that evolved independently are called ______ structures.

analogous

In birds and mammals, feathers and hair develop from structures on the surface of the embryo called placodes. Recently, researchers found placodes in the embryos of several groups of reptiles, indicating that scales of reptiles, feathers of birds, and hair of mammals

are homologous structures

Earth's continents are in motion; this is referred to as

continental drift.

Continental drift is the term used to describe the fact that the ______ of Earth are in motion.

continents

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

Organisms have changed over time; new species have appeared while other species have gone extinct. This is a description of

macroevolution

Label the cladogram of terrestrial vertebrates.

(clockwise) common ancestor mammals, common ancestor birds, clade, reptiles, taxon

Researchers discover that a North American bird species called a brown thrasher has a very similar beak structure to one of Darwin's finches. The specialized beak structure, which independently evolved in each species, allows the birds to break open seeds. What terms might relate these two beaks? Select all that apply.

- Convergent evolution - Analogous - Homoplasy

Which of the following hypothetical observations during the voyage of the Beagle would have provided evidence to support Darwin's theory of evolution? Select all that apply.

- Different species of orchids on the South American coast varied only slightly in color, shape, and bloom timing - An inhabitant of South America was selectively breeding pigs to have the best-tasting meat. - In a population of wallabies in southern Australia, individuals have differing tail width-to-length ratios

Select all the reasons why it is difficult for biologists to determine whether a speciation event is allopatric, sympatric, or parapatric.

- It is hard to detect all the barriers that are important to different species. - The definitions of allopatric, parapatric, and sympatric speciation represent three points along a continuum.

Select all of the following that are true about molecular clocks.

- They can be used to estimate when humans and chimps diverged from a common ancestor. - They use the mutation rate of genes to determine the time of divergence from a common ancestor.

Select all the key properties of evolutionary adaptations.

- They can confer reproductive success. - They are heritable.

Select all of the characteristics of the ancient fossil snake Najash that suggest snakes evolved on land. Refer to the Investigating Life feature.

- a pelvis - a sacrum - functional legs

Select all of the following that occur in natural populations and that violate the assumptions of the Hardy-Weinberg equilibrium.

- allele frequencies can change due to chance events - migration among populations occurs - mating is often nonrandom

Match the type of speciation on the left with its correct figure on the right, using the letters on the diagram.

- allopatric speciation: No contact between populations - parapatric speciation: Populations share a border area - sympatric speciation: Continuous contact between populations

Match the type of speciation on the left with its description on the right.

- allopatric: no contact between the populations - parapatric: populations sharing a border - sympatric: continuous contact between populations

Select all the examples of nonrandom mating.

- choosing mates based on certain characteristics - mate choice based on social position - mating only within a specific group

Match the type of prezygotic reproductive barrier on the left with its example on the right.

- habitat isolation: Choice, Herbivorous ladybird beetles feed on different types of plants. - temporal isolation: Field crickets mature at different times - behavioral isolation: Frog mating calls differ

Common ancestry can be indicated by which of the following? Select all that apply.

- homologous structures - nucleotide and amino acid sequence similarities

Select all the ways in which humans are creating situations that cause extinctions of animals and plants on Earth.

- introducing nonnative species into new habitats - releasing pollution into the atmosphere and water - destruction of habitat - fragmentation of habitat

Select all of the following that are mechanisms of evolution and that can alter allele frequencies.

- mutation - natural selection - gene flow

Select all the reasons that could cause a species to go extinct.

- new predator - new disease - natural disaster - habitat loss

Select all of the following that are true about vestigial structures.

- persist in related organisms even when no longer used - include pelvic and hindlimb bones in whales

Select all of the following that are prevented by postzygotic reproductive barriers.

- survival of offspring to maturity - production of fertile offspring

What kinds of molecular comparisons are useful for determining species relatedness? Select all that apply.

- whole-genome comparisons - single-gene sequence comparisons - gene function comparisons - the protein cytochrome c - amino acid sequence of a common protein

In a population of 200 fish, 182 fish are blue and 18 fish are red. Eighty-four of the 182 blue fish are heterozygous for the color trait. What is the frequency of the red allele in the population? (Assume simple dominance/recessiveness of the color allele.)

0.3

In the population of 25 ferrets shown in the image, what will be the proportion of heterozygous individuals in the next generation, assuming the population is in Hardy-Weinberg equilibrium? (Click on the one correct answer.)

0.48

The croaking trait of bullfrogs is in Hardy-Weinberg equilibrium. The dominant allele (D) confers a very deep croak, and the recessive allele (d) confers a higher-pitched croak. Ninety percent of the alleles in the population are dominant for this trait. What proportion of the population of bullfrogs has a very deep croak?

0.99

Decide which type of fossil formation is described. Drag and drop each answer choice into the appropriate column. 1. Cast 2. Petrifaction 3. Compression 4. Impression

1. A squirrel dies in the mud and the body rots away. Mud fills up the space where the body was and hardens into a rock. Whats left is a piece of rock that looks like a squirrel. 2.A squirrel dies and is buried by soil. Over time water seeps through the soil and the squirrels tissues are replaced with minerals. Whats left is a stone that looks like a squirrel sculpture. 3. A squirrel dies and is covered by sediment. Over time its tissues are chemically altered as the area develops into sedimentary rock. What is left is a squirrel sized lump of coal.(fossil fuel) 4. A squirrel makes foot prints in the mud. Later the mud hardens into a rock. Whats left is a piece of rock with foot prints in it. In birds and mammals, feathers

Classify each example into the correct evolutionary evidence category. 1. Biogeography 2. Anatomy 3. Molecular comparisons 4. Development

1. Distinct species on either side of the wallace line. 1. Distribution of fossils on five continents 2. Vestigeal structures. 2. Homologous structures of vertebrate forelimbs. 3. Amino acid sequence difference between two species. 3. Similarity in DNA sequences. 4. Similarities in the embryo stage of species.

Evidence of an organism that is more than ______ years old is called a fossil.

10,000

What can you conclude about the evolution of chimpanzees and humans from the skull comparisons in the figure?

Although skulls in adults look different, comparisons at the fetal stage reveal homology.

______ extinction results from a gradual loss of a species as populations face new challenges, whereas ______ extinction results from the loss of a great number of species in a relatively short time period.

Background; mass

_______ dating involves assigning a specific age to a fossil by testing either the fossil or the sediments above and below it.

Carbon

Who was a collector and captain's companion on the five-year voyage of the HMS Beagle?

Charles Darwin

What has made the comparison of a few bases, one gene, or families of genes possible?

DNA sequencing

True or false: The goal of natural selection is to produce perfect organisms.

False

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

The biological species concept proposed by ______ states that a biological species is a population whose members can interbreed and produce fertile offspring.

Mayr

What describes allopatric speciation?

Microevolutionary forces occur in two populations that are isolated from each other, and eventually they can no longer interbreed.

Select the correct statement about natural selection.

Natural selection does not have a goal of a perfect organism.

______ are evolutionary trees that are used by biologists to represent hypothesized relationships among species or groups.

Phylogenies

How do reproductive barriers relate to the biological species concept?

Reproductive barriers prevent two populations from interbreeding, producing unique species.

What describes the postzygotic isolating mechanism called hybrid breakdown?

Second-generation hybrid offspring are unable to reproduce.

Why are soft-bodied organisms less likely to leave a fossil trace than hard-bodied organisms?

Soft body parts are less likely to be preserved than shells, bones, or teeth.

Prior to the formation of a land bridge about 3 MYA that allowed placental mammals to invade, marsupials were diverse and abundant on what other continent besides Australia?

South America

Select the correct statement from the ones below with respect to how speciation may occur.

Speciation may be gradual or occur quickly in bursts.

Why might a plant invest energy to produce and store nectar in extrafloral nectaries?

The nectar recruits plant-defending insects.

Rank the three types of speciation, from the form with complete reproductive isolation at the top to the form with continuous intermingling of the species at the bottom.

Top: allopatric Mid: parapatric Bot: sympatric

In regards to evolution, which deer has the highest "fitness"?

a deer that produces offspring that survives the most

Studies have shown that the formation of ______ explains the migration of animals between North America and South America and the possible cause of the extinction of most marsupial mammals on the South American continent.

a land bridge

The type of dating that involves testing an actual fossil, or the layers above and below it, and assigning an age to the fossil in relation to the present is called ______ dating.

absolute

A(n) ______ is a feature that provides a selective advantage to an organism because it improves its ability to survive and reproduce.

adaptation

______ radiation is a situation in which a population inhabiting an environment with new resources gives rise to multiple specialized forms in a relatively short time.

adaptive

A process called ______ created the diversity of species in Hawaiian honeycreepers following the relocation of a mainland species to an island.

adaptive radiation

Speciations can happen in rapid bursts during a(n) ______, in which a population inhabiting a patchy or heterogeneous environment gives rise to multiple specialized forms in a relatively short time period.

adaptive radiation

The type of speciation that occurs when two populations are separated by a physical barrier so that they cannot interbreed is called ______ speciation.

allopatric

According to the Investigating Life essay, _____ evidence of the vertebrate transition to land helped scientists discover the fossil ______, which has features of both fish and amphibians.

biogeographical; Tiktaalik

Geographical barriers such as deep ocean trenches, mountains, and isolated islands greatly influence the distribution and origin of species on Earth. This field of biology is called

biogeography

A diagram depicting evolutionary relationships based on shared derived characters is called a

cladogram

What is an example of a compression fossil?

coal

Homologous genes can be identified in different organisms by locating a gene in one organism and then

comparing it to known genes in databases.

A(n) ______ fossil forms when an organism dies and becomes buried in sediment that packs down the organism as sedimentary rock forms.

compression

The root cause of extinction is when microevolution in a species doesn't keep up with

environmental change.

Descent with modification describes the process of

evolution

One definition of ______ is "changes in traits from generation to generation."

evolution

Phylogenies are trees of organisms that depict hypotheses about

evolutionary relationships.

A species becomes ______ when all members of that species have died.

extinct

If speciation is the beginning of a species, then _______ is the end of a species.

extinction

True or false: Charles Darwin was the first to attempt to explain how the diversity of life arose.

false

The genetic contribution of an organism to the next generation is referred to as

fitness

Natural selection requires genetic variation, competition for limited resources, overproduction of offspring, and unequal reproductive success. What requirement does the following sentence represent? A subset of finches that have large beaks is contained within a population of finches that mostly have small beaks.

genetic variation

The modern evolutionary synthesis connects natural selection and

genetic variation that arises by mutation

The two-word name assigned to every species, as devised by Linnaeus, consists of the ______ of the organism followed by a second word that designates the species.

genus

Linnaeus designed a system of assigning names to organisms. The first word in an organism's scientific name designates the broader classification level called the _______ of the organism, and the second word designates the _______

genus; species

Small, incremental changes over numerous generations is the model of speciation described by Darwin and is known as

gradualism

Evolutionary theory

has developed over several centuries

Homologous genes are best described as genes that

have a common ancestral gene.

If the similarities between structures of two different organisms reflect common ancestry, then the structures are

homologous

What may be causing a current sixth mass extinction on Earth at a rate of about 20 to 200 extinctions per million species per year?

humans

A cladogram depicts

hypothesized evolutionary relationships.

Mass extinction is the loss of species

in large numbers over a short time.

The fossil record is often ______ because fossils can be destroyed or buried too deep.

incomplete

Mate choice, such as in sexual selection,

leads to nonrandom mating.

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

Differences and similarities in the DNA or protein of organisms is ______ evidence that can reveal evolutionary relationships.

molecular

a(n) ______ clock uses differences in DNA to determine when organisms diverged from a common ancestor.

molecular

What type of evolutionary evidence is the most objective because it allows the comparison of clearcut numbers, such as percent similarity between two species?

molecular comparisons

New alleles that might allow a bacterium to become resistant to an antibiotic arise through

mutation

What occurred in the red bacterial cell that generated genetic diversity? (Click on the one correct answer.)

mutation

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

Directional, disruptive, and stabilizing are all types of ______, in which certain phenotypes are favored over others.

natural selection

What mechanism of evolution changes the genetic makeup of a population by favoring alleles that increase reproductive success?

natural selection

When a portion of a population can no longer breed and produce fertile offspring with the rest of the population, then a ______ has formed.

new species

A population of snails is separated when an eight-lane highway is built. After 50 years, the two separate populations can no longer interbreed. This describes the process of

new species forming.

The study of fossil remains and other clues to past life on Earth is referred to as

paleontology

Homologous genes within a single species are said to be

paralogs

If a new species begins to form when a portion of a population enters a new habitat bordering the rest of the population, this represents a case of ______ speciation.

parapatic

The type of speciation that occurs when part of a population enters a new habitat bordering the range of the parent species is ______ speciation.

parapatric

A(n) ______ group of organisms contains a common ancestor and some, but not all, of its descendants.

paraphyletic

If a group of species contains a common ancestor and some but not all of its descendants, it is referred to as being

paraphyletic

Fertilization between two species can be prevented by ecological isolation, temporal isolation, behavioral isolation, and others. These are examples of ______ reproductive isolating mechanisms.

prezygotic

Hardy-Weinberg equilibrium is seldom seen in natural populations because

selection takes place in natural systems.

A difference in the appearance between males and females of a species is called

sexual dimorphism.

What is an example of protein sequence similarity among species?

sheep keratin and the keratin in human hair

Two different models of ______ are gradualism and punctuated equilibrium.

speciation

According to this chapter's Investigating Life essay, an extrafloral nectary is a structure that ______ and is not a ______.

stores nectar; flower

Cuvier thought that lower layers of rock were older than those above them. This principle describes

superposition

The type of speciation that occurs when populations diverge genetically while living in the same physical area is called ______ speciation.

sympatric

Suppose that many species of cichlids in one lake in Africa diverged from a common ancestor, which also inhabited the lake. What process has occurred among cichlids in this lake?

sympatric speciation

If a population diverges genetically from its parent population while remaining in the same physical area, this is an example of ______ speciation.

sypatric

The study of classification is called ______, which incorporates both taxonomy and phylogenetics.

systematics

Systematics, the study of classification, incorporates two interrelated specialties, which are

taxonomy and phylogenetics.

What evolutionary tree in the image represents the gradualism model of speciation?

the tree on the left

How many domains of life, the most inclusive level of taxonomic hierarchy, are organisms grouped into?

three

Homologous genes can be the result of a misaligned crossover event and random mutations accumulated over the course of many generations.

true

A structure that has no apparent function in one species yet is homologous to a functional organ in another species is called a ______ structure.

vestigial