Biology Chapter 22: Evolution
In some populations, 1 in 500 people have sickle cell disease. What reason does the film give for why a potentially deadly, inherited disease is found at such high frequencies?
Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population.
What did researchers discover about the genetic mutation causing lactase persistence?
It is found in a regulatory region (a "switch") upstream of the lactase gene.
Why is the enzyme lactase necessary to digest dairy products?
Lactase breaks down lactose into smaller molecules that can be absorbed by the cells that line the small intestine.
Most people are lactose intolerant as adults, but nearly everyone produces sufficient lactase as an infant. However, in some cases, genetic mutations can occur that make an infant lactose intolerant. From an evolutionary perspective -- over thousands of years -- why would lactose intolerance in infants be very rare in the population?
Lactose intolerant infants could not digest breast milk and therefore usually died, never having the chance to pass the mutation on to their children.
What does Dr. Carroll mean when he says, "while mutation is random, natural selection is not"?
Natural selection acts on traits. Natural selection favors some mutations. Mutations for advantageous traits are more likely to be passed on to the next generation.
Recent research supports which of the following?
Early humans went back and forth between hunting and gathering and agrarian societies.
Which of the following statements is true?
Environmental changes may create new habitats, favoring the development of new species. Submit
Which one of the following is TRUE regarding fossils?
Even though fossils from more than 200,000 different species have been found, the fossil record remains incomplete.
Because fossils have been found from over 200,000 species, the fossil record is now considered complete.
False
Which of the following would best support the most recent ideas regarding early humans?
Finding human fossils in many different habitats.
How do foraminifera found in rock layers above the K-T boundary compare to those in rock layers below?
Foraminifera above the boundary are smaller and less diverse than those below.
Which of the following statements about fossils is true?
Fossils are most likely to be found in sedimentary rock.
Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct?
Gene flow causes the frequency of the brown allele to increase.
The Grants witnessed strong selection during droughts in 1977 and 1985. Compare the two droughts.
-Both droughts events provided strong natural selection on medium ground finch populations. -Both droughts resulted in changes to food sources that favored the survival of some medium ground finches over others.
Darwin and Wallace made independent observations in different parts of the world. Which statements are true?
-Both witnessed nature up close and realized it was a battlefield with massive casualties. -Both observed slightly different species on nearby islands and concluded that species could change over time. -Both collected huge numbers of specimens and realized that individuals vary within species.
The evolution of eukaryotic cells began approximately ________ years ago.
1.7 billion
Why should we not view lactose intolerance as a disease in adult humans?
Adult humans did not consume dairy products until fairly recently in our evolutionary history. Submit
To learn more about the earliest humans, which two areas would be best to conduct research?
Africa and Eurasia
Which of the following is true?
All housecats have the same size tongue papillae.
Which of the following are causes of evolutionary change?
All of them (Mutation,Genetic Drift, Gene Flow, Natural Selection
Which of the following statements is NOT consistent with demonstrating the validity of the theory of evolution?
Although evolutionary studies cannot be carried out in the laboratory or in nature, statistical evidence points to the validity of evolutionary theory.
Which of the following statements supports the conclusion that the common ancestor of modern chimps and modern humans lived around 7 million years ago?
Analysis of modern human and modern chimpanzee protein and DNA sequences suggests that their lineages diverged about 7 million years ago.
Which discovery supports the hypothesis that evolution of the lactase-persistence trait was driven by the use of milk in pastoralist cultures?
Ancient pots used to hold milk are about the same age as the lactase-persistence mutations.
What did scientists learn from other fossils found in the same sediment layer as Ardi?
Ardi lived in a woodland habitat
The scientific community was slow to accept the asteroid impact hypothesis. Why?
At the time, most geologists thought that the Earth changed slowly and gradually, and not by major catastrophes.
What makes bed bugs different than most other blood-feeding parasites?
Bed bugs prefer humans over other hosts.
This molecule is thought to be the first self-replicating organic molecule to have formed on Earth.
RNA
Select the statements about the K-T boundary that are true.
The K-T boundary dates to 65 million years ago (when the dinosaurs disappeared).The K-T boundary separates rock layers of the Cretaceous period from those of the Tertiary period.The K-T boundary in Zumaia, Spain is sharp--representing an abrupt change in the marine ecosystem.
Which of the following is TRUE about members of the Homo genus?
The earliest known member of the Homo genus is the species Homo habilis.
Many blood-feeding parasites carry diseases but bed bugs do not. What is the most logical explanation for this?
The infectious agent is inactivated within the gut of the bed bug.
As Wallace traveled the Malay Archipelago, he noticed that western islands had placental mammals, like monkeys. Eastern islands had marsupial mammals, like kangaroos. How did Wallace explain this distribution?
The western islands were once connected to Asia and the eastern islands had been connected to Australia. The islands had never been connected to each other.
mutations are always _________
a change in an individuals DNA
Which of the following anatomical features of the 3.2-million-year-old Australopithecus fossil known as "Lucy" suggest she was a bipedal hominid?
a much shorter hip bone that is broader from front to back and wraps around the side.
Suppose that a mutation for lactase-persistence occurred in each of the populations described below. In which populations would the mutation be more likely to increase in frequency over time because of natural selection?
a population that raises wheat and sheep
Which of the following places is likely to have the highest level of local extinction?
a tropical forest in guyana
Which of the following best describes evolutionary "fitness"?
ability to survive and reproduce relative to other members of a population
Mass extinctions create conditions that promote _____.
adaptive radiation
The appearance of an evolutionary novelty promotes _____.
adaptive radiation
The different finch species found on the Galápagos Islands probably arose as a result of _____.
adaptive radiation
_____ is rapid speciation under conditions in which there is little competition.
adaptive radiation
__________ refers to the development of many new species from a single ancestor in a relatively short time.
adaptive radiation
The process of using oxygen to extract energy from organic molecules is called
aeriobic metabolism
How could an asteroid impact kill off such a large number of different species all over the planet?
all
How could milk-drinking have provided strong favorable selection for lactase persistence?
all
Which of the following can affect the makeup of the gene pool within a population?
all
Darwin and Wallace independently arrived at the same conclusion that species change over time. Which observations supported their conclusions?
all are correct
Feathers either play a role, or may have played a role, in _____.
all of these
A bird's wing and an insect's wing are both evolved for flight, but they evolved from entirely different structures. These wings are examples of __________ structures.
analogous
The wings of birds and insects share similar functions but evolved from different structures; therefore, the wings of birds and insects are said to be
analogous
Which of the following is(are) homologous to the bones in this image?
the other brown one
As oceans began to form on Earth billions of years ago, they were small, warm, and not very salty.
true
Comparative biochemistry is the scientific discipline that examines similarities and differences between molecules, and infers evolutionary relationships from them.
true
Geographical barriers, such as large bodies of water and mountains, can prevent gene flow.
true
Periods of adaptive radiation are most likely to occur after a change in the environment causes new habitats to form.
true
Primitive photosynthetic organisms were responsible for producing oxygen gas in the atmosphere.
true
RNA is believed to have evolved before DNA and proteins.
true
The largest mass extinction in the history of Earth was the Permian-Triassic, accompanied by extremely high carbon dioxide levels and global warming.
true
The theory of evolution is the single most unifying concept of biology today.
true
There was no protective ozone layer early in Earth's history, which allowed Earth's surface to be bombarded with ultraviolet radiation.
true
In 2004, archaeologists unearthed a female skeleton on the Indonesian island of Flores. Despite a short stature, similar to Australopithecus, she was classified as a member of the more modern genus Homo because of which of the following traits?
upright bipedal posture and a human-like jaw for chewing
Examination of the skeleton of whales shows bones similar to those in the human pelvis. In humans, the pelvis provides support and attachment for the lower limbs. In whales, these bones would be considered:
vestigal
What kind of habitat did tiktaalik live in?
warm, freshwater swamp
When should a lactase supplement be taken in order to be most effective, and why?
at the same time the dairy product is consumed, so that the lactase will be in contact with the lactose Submit
Which of the following shared characteristics of living birds and theropod dinosaurs provided support to the hypothesis that birds evolved from dinosaurs?
birds and theropods have S-shaped necks -birds and many theropods have a wishbone (or furcula) -birds and many theropods have feathers -birds and theropods have hollow bones that are strong, but light
Which of the following have coexisted with modern Homo sapiens?
both Homo neanderthalensis and Homo floresiensis
Compare sickle cell disease and malaria.
both are potentially lethal diseases
A particularly harsh winter kills off 90% of the individuals in a population of reindeer. The resulting population's gene pool is no longer representative of the original gene pool. This is an example of __________.
bottleneck
Which structure is not homologous to the other three?
butterfly wing
How do scientists know that the hominid called "Ardi" is about 4.4 million years old?
by using radiometric dating techniques on the volcanic deposits found above and below the layer containing Ardi
After a long period of coevolution, the photosynthetic bacterium consumed by the predatory cell became the cellular organelle known as the:
chloroplast
Pharyngeal slits in embryos can be used to demonstrate ________.
common vertebral ancestral line
Cytochrome c is a small protein that is found in almost all living organisms. Comparison of the structure of cytochrome c from different organisms to infer evolutionary relationships is an example of the scientific discipline of
comparative biochem
The process of ________ has had a major impact on species distributions worldwide.
continental drift
Cytochrome c oxidase is an enzyme found in countless organisms across the living world. Studying this enzyme is valuable for our understanding of evolution because ________.
differences in cytochrome c oxidase can be used to demonstrate the time frame of divergence between different branches of the evolutionary tree
Different finch species have beaks of different shapes and sizes. What do these beak differences tell us?
different finch beak shapes are evidence that finch species adapted to different environments over many generations
What is the most important characteristic of anole lizard species that keeps members of one species from mating with members of another species?
different species living in the same habitat have different dewlaps
Which evidence is consistent with the asteroid impact hypothesis?
everything EXCEPT plutonium 244
Which of the following traits can be used to differentiate humans from our closest living primate relatives?
extensive tool use, bipedality, large brain size
Dinosaurs and modern humans coexisted for about a million years.
false
Which of the following statements about bird evolution are accurate based on the evidence presented?
feathers may have originally evolved for insulation feathers may have originally evolved for interspecies comunication and display
Which of these events occurred most recently in the history of Earth?
first humans
Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?
flat head with eyes on top, interlocking ribs, a neck
The wing of a bat is homologous to the _____ of a whale.
flipper
Which of these events occurred earliest in the history of Earth?
formation of oxygen
The enzyme lactase breaks the sugar lactose into which compound(s)?
galactose and glucose
The evolution of populations due to chance is
genetic drift
Differences in populations may arise over time when physical structures in the environment, such as mountains or large bodies of water, change. In the context of evolution, these structures are referred to as
geographical barriers
In a population with brown and green alleles for color, genetic drift
has more effect on the evolution of a small population.
In 1949, Dr. Tony Allison observed a high frequency of Kenyans carrying the sickle cell allele in coastal areas and near Lake Victoria, but a lower frequency in the highlands. What did he hypothesize?
he hypothesized that there was a connection between malaria and sickle cell disease.
The structure of the gray whale cytochrome c protein is 5 amino acids different than the hippopotamus cytochrome c, but it differs from the cytochrome c in bottlenose dolphins by 16 amino acids and in harbor seals by more than 50 amino acids. From these data, one could hypothesize that among these animals, gray whales are most closely related evolutionarily to
hippopotomus
Based on fossil evidence, which of the following hominins existed for the longest period of time and dispersed the farthest geographically?
homo erectus
Based on the figure above, which member of the Homo genus appears to have existed the longest, persisting for nearly 2 million years?
homo erectus
humans are _____
homo sapiens
The figure above shows the skeletal structure of the forelimbs of several vertebrates. Because these skeletal elements are similar in form and are believed to have evolved from a common ancestral structure, they are said to be
homologous
In which country would you most likely find a higher incidence of lactase persistence?
in a Scandinavian country where people historically raised dairy cattle and made cheese
The discovery of the new species, Homo floresiensis, created controversy among anthropologists because __________.
it had long been assumed that a large brain size was required for sophisticated toolmaking and complex social organizations
How did Dr. Jack Horner's discovery of dinosaur nesting grounds support the hypothesis that birds evolved from a group of dinosaurs?
it provided evidence that dinosaurs raised and cared for their young in colonies like many birds Submit
Which characteristic was NOT advantageous for organisms in the million years after the catastrophic asteroid impact?
large body size
Humans are classified as hominoids because
larger bodies and bigger brains than other primates
Which of the following is an example of an adaptation in anole lizards?
long legs in the anole lizards that live primarily on the ground and tree trunks
Sexual selection is based on ________.
phenotype
On the early Earth, the evolution of ________ created oxygen gas in the atmosphere.
photosynthesis
Which of the following milestones happened first?
photosynthesis evolved
Humans belong to all of the following taxonomic groups EXCEPT __________.
prokaryote
Which of the following is a tetrapod?
reptile, bird, amphibian,mamal
As climate change continues, species in which of the following marine ecosystems are likely to benefit the most?
rocky areas near the shore
Four individuals measured their baseline blood glucose, then drank a litre of milk. They then measured their blood glucose levels at regular 15 minute intervals for 60 minutes. The results are shown in the graph below. Which individuals are lactase-persistent?
sarah and peter
Predict what will happen to the frequency of the sickle cell allele in areas where malaria has been eradicated.
sickle cell wil decrease in frequency
A key characteristic of modern birds is flight powered by feathered wings. Which of the following pieces of evidence support the hypothesis that the first feathers served a purpose other than flight?
some feathered theropods were not capable of flight
You invent a new cat brush that mimics a cat's tongue. Which of the following liquids does your brush contain?
synthetic cat saliva
What was the critical piece of evidence that supported the hypothesis that an asteroid struck Earth 65 million years ago?
the Chicxulub crater in Mexico
Why doesn't Dr. Logan feel the bed bug feeding on him?
the bed bug injects an anschtiectic as it feeds
Why was the discovery of organisms, such as Archaeopteryx, that have a mix of traits usually associated with two different groups considered validation of Darwin's theory of evolution?
the discovery provided evidence that species descend with modification from other species
If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles,
the frequency of the green allele will increase.
In the lab, Nachman examined dark mice from two different populations living hundreds of miles apart. The mice looked nearly identical. Their dark color was caused by two different genes. What does this tell you?
-Dark fur color evolved independently on each lava flow. -There are at least two genes involved in creating dark mouse fur. -Two completely different mutations in two separate genes can generate the same phenotype. -Under very similar conditions, natural selection can favor very similar adaptations.
No two species of anoles lizards living in the same geographical location have dewlaps of the same size, shape or color. Why?
-Female anole lizards distinguish males of their own species from males of other species by their dewlaps. -Male anole lizards use dewlaps to court females. -Dewlap color is under strong selection. Dewlaps that contrast with a lizard's environment are more effective for communication. -Differences in dewlaps keep different anole species reproductively isolated, even when they live together.
In 1977, medium ground finches on Daphne Major experienced a severe drought. The figure shows the beak depths of the initial population before the drought (red bars) and of the drought survivors (black bars). What do the data show?
-Finches with larger beaks had a survival advantage in the 1977 drought. -More than one-half of the initial population died during the drought. -The most common beak size of the initial population was 8.8 millimeters. A very small proportion (~5%) of the initial population with this beak size survived.
How did Dr. Allison test his hypothesis that sickle cell disease was connected to malaria?
-He expanded his study area beyond Kenya to the rest of East Africa to see if malaria and sickle disease were connected. -He evaluated blood samples for malaria parasites and the presence of sickle cells.
How does Dr. Allison's work provide an example of natural selection in humans?
-In areas without malaria, individuals with two sickle cell alleles reproduced at lower rates than those without sickle cell disease. -In areas with malaria, individuals with one sickle cell allele reproduced at higher rates than those with no sickle cell alleles.
The film defines species as populations whose members don't interbreed. What keeps different Galápagos finch species from mating?
-Males only court females that have a similar beak and similar size. -Geographic isolation and different environments led to changes in traits that affected mating. -Individuals recognize and only respond to songs of their own species.
What observations and evidence have Jonathan Losos and his colleagues gathered to support the theory of natural selection?
-On each of the four large Caribbean islands, Losos observed the same distribution of anole lizard body types. -When Losos and colleagues transplanted tree-dwelling anoles to small, hurricane-scrubbed islands without trees, the lizards evolved to have shorter legs after only a few generations. -DNA evidence suggests that the different lizard body types (twig, grass, etc.) evolved independently on each of the four large Caribbean islands.
Jonathan Losos and colleagues conducted experiments on small, hurricane-swept islands as "natural laboratories." Which of the following statements is true?
-There are many small islands with similar environments, meaning that researchers can repeat their experiments and observations in several locations. -Islands scrubbed by hurricanes allow researchers to introduce new lizard populations and observe their evolution. -Natural selection can lead to rapid changes. The average leg length of lizard populations decreased within a few generations.
Which of the following is an accurate statement regarding human evolution?
-The fossil record contains creatures with features that are intermediate between those of modern humans and quadrupedal apes. -In the latest phase of human evolution, there has been a greater reliance on culture. -The first humans evolved in Africa.
Which evidence supports the hypothesis that four-limbed animals came from fish?
-The fossil record shows more and more tetrapod-like fish before the appearance of tetrapods about 365 million years ago. -Fish and four-limbed animals have very similar embryos. -DNA analysis shows that fish are tetrapods' closest relatives. -Both fish and four-limbed animals are vertebrates. Submit
Which observations led Darwin to establish a relationship between extinct and living animals?
-The fossilized remains of giant sloths were found in places where smaller sloths now live. -The bony shells of armadillos resembled the shells of ancient Glyptodon fossils.
If a person has two normal copies of the hemoglobin allele, which statements are true?
-The person is susceptible to malaria. -The person is homozygous at the hemoglobin locus.
After his journey on the HMS Beagle, Darwin made this now-famous sketch in his notebook. Which ideas does it represent?
-all species are connected to one another in a family tree -all species are linked to one another by common chemistry -species descend from other species just as naturally as children come from parents.
The 150-million-year-old Archaeopteryx fossil has birdlike features such as feathered wings, but it also has characteristics that we associate with living reptiles. Which of the following are considered reptilian characteristics of Archaeopteryx?
-claws on the ends of each digit in the "hands" -teeth in the jaws -long, bony tail
The following is a list of molecules and organisms that formed during the early days of Earth. Which one of the following best represents the order in which they are believed to have arisen? 1. RNA2. aerobic organisms3. simple organic compounds4. anaerobic organisms
3,1,4,2
Life began on Earth approximately ________ years ago.
3.8 billion
How many years ago did humans and Old World monkeys split from their common ancestor?
30 million years ago
In what order did events occur that led to life on Earth? (1) evolution of aerobic organisms, (2) evolution of photosynthetic organisms, (3) production of O2 and its increase in the atmosphere, (4) self-replicating RNA develops
4,2,3,1
You have a house cat. Which of the following would likely work the best for your cat?
A brush that penetrates her fur and reaches the skin.
How does the term "lactase persistent" relate to the term "lactose tolerant"?
A lactase-persistent person is lactose tolerant.
Which of the following is NOT a characteristic of a mutation?
A mutation is almost always adaptive and thus produces new genetic information for the cell.
Which of the following statements about Darwin is FALSE?
Darwin was the first to develop an evolutionary theory.
DNA evidence suggests that anole lizard species from the four largest Caribbean islands are related as shown in the figure. Which statement is true?
Different body types evolved repeatedly and independently on each island.
The amino acid sequence of the protein cytochrome c is compared between three different species: gray whale, hippo, and elephant. It is found that gray whale differs from hippo by 5 amino acids, hippo differs from elephant by 12 amino acids, and gray whale differs from elephant by 30 amino acids. From these data, you could hypothesize that __________.
Gray whales are most closely related to hippos.
Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection?
Green beetles leave more offspring than brown beetles because they are better at finding food.
Iridium is a component of cosmic dust that rains down upon the earth at a constant rate. Why did Luis Alvarez suggest measuring iridium levels in the K-T boundary?
He was looking for a way to determine how quickly the layer had been deposited.
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.
Which of the following statements about the hominoids is FALSE?
Hominoids typically are bipedal and walk upright.
When dark-colored fur gives mice a 1% competitive advantage and 1% of the population begins with dark fur, in about 1000 years, 95% of the population will have dark fur. Which of the following statements is true?
If dark-colored rock pocket mice had a competitive advantage of 0.1%, it would take longer for 95% of the population to have dark fur.
What did Wallace conclude from observing that the bones in manatee flippers look similar to the bones in a human arm and hand?
Manatees' arm and finger bones are evidence that manatees share a common ancestor with land mammals.
Genetic evidence supports which of the following explanations for the presence of 13 different finch species on the Galápagos islands?
Many years ago, a small population of a single finch species migrated to the islands and evolved into the current 13 species.
Which of the following is most certain?
Modern humans first appeared in Africa.
When Charles Darwin set sail on the HMS Beagle, what did he and most of his contemporary scientists think about the origin of species?
Most scientists, including Darwin, thought each species was specially created by God in its present form and did not change over time.
Which of the following statements about mutations is true?
Mutations provide the genetic variation upon which evolution works.
New research leads anthropologists to believe that many societies lived like the Nambikwara. What would this entail?
Societies based on the dry and rainy seasons.
What does the bed bug illustrate in regards to evolution?
Speciation can occur in just a few thousand years.
Some scientists are conducting research on the "saliva" of bed bugs. Which of the following is the most logical medical benefit from this research?
Using the anticoagulant to prevent blood clots in humans.
The top figure shows beak sizes of the 1976 finch population before the drought of 1977 (red bars) and after the drought (black bars). The lower figure shows the beak sizes of the offspring of the drought survivors in 1978. What do these figures tell us?
The overall beak depths of the 1978 offspring population are larger the original 1976 population.
Why do we often get an itchy red bump after being bitten by a bed bug?
The proteins injected by the bed bug trigger an inflammatory response in the human body.
Which of the following is the best example of a species that is locally extinct?
The red-breasted nuthatch, missing from part of its range.
Louis and Mary Leakey found two different fossil hominid skulls at Olduvai. Which of the following statements about the skulls is true?
The second skull represented a species more closely related to modern humans than the first skull's species.
How do lactase supplements help people who are lactose intolerant?
The supplements provide the enzyme that breaks down the lactose in dairy products.
Why do dark-colored rock pocket mice on dark lava flows have white bellies?
There is no selection for dark bellies by visual predators.
What happened in the 1970s to some of the Galápagos Island finches (Geospiza fortis, specifically) that demonstrates that these birds underwent a rapid microevolution?
There was a drought, and the birds with deeper beaks were selected for because they could better crack the large, tough seeds and thus did not starve.
Bed bugs probably evolved from bat bugs. Which statement best describes how this likely happened?
There were two populations of bat bugs, one feeding on humans, and one on bats. Reproductive isolation, mutation, and natural selection led to speciation.
Why did Shubin and Daeschler search in the Canadian arctic for fossil evidence of the transition from fish to tetrapods?
They hypothesized that the transitional fossils were in sedimentary rocks older than 365 million years ago, when the first tetrapods appear in the fossil record.
How did the Grants test their hypothesis that differences in birds' songs can keep different species of finches from breeding with one another?
They played the songs of medium ground finches and cactus finches through a loudspeaker to see which species responded to each song.
Why have we NOT found examples in the fossil record of every animal that ever lived on Earth?
To become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock. -To become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose. -Many fossils remain buried. We can only find them when they are exposed by erosion or excavation.
Lactose intolerance in infants is more common in the population today than it was a hundred years ago. Why?
Today there are alternatives to breast milk, such as lactose-free formula and soy milk, so lactose intolerant infants can survive.
What is a transitional fossil?
Transitional fossils have features that are intermediate between ancestors and descendants. Submit
Recent discoveries indicate toolmaking among species of the Homo genus dates back to at least 3 million years ago.
True
With the advent of photosynthesis, many of the anaerobic organisms present on Earth went extinct.
True
Evolution of shorter legs in anole lizards placed on small, hurricane-scrubbed islands is an example of which type of evolution?
microevolution
Generation-to-generation change in the allele frequencies in a population is _____.
microevolution
After a long period of coevolution, the aerobic bacterium consumed by the predatory cell became the cellular organelle known as the:
mitochondrion
Which of the following agents of microevolution can create new genetic information in a population?
mutation
The most important force in evolution is ________.
natural selection
Which of the following agents of microevolution consistently leads to adaptation of organisms to their environment?
natural selection
Current thinking is that RNA was the first self-replicating molecule that formed on early Earth. In what environment is it thought that RNA first formed?
on clay along ocean shorelines
The bacteria initially persist in the predatory cell because:
the predatory cell is unable to digest the bacteria.
Which discovery ultimately overturned the prevailing perception that all dinosaurs were large, slow, and lumbering?
the small theropod dinosaur Deinonychus, which had a large sickle-shaped claw on each of its hind limbs
How did the great transition from fish to tetrapod occur?
the transition occurred gradually over time so there are many intermediate forms.
When two species contain identical or nearly identical molecules such as proteins, this suggests
the two species may share a common ancestry.
Groundhogs are closely related to marmots. Based on this information, how are they likely to be changing as the climate warms?
they are getting larger
You are a herpetologist studying how milk snakes in Minnesota respond to climate change. Which of the following would be a morphological change?
they are increasing in average length
Why did dark-colored rock pocket mice first appear in a population of light-colored rock pocket mice?
they have a genetic mutation that affects their fur color
Your aunt conducts research on ocelots in Central America. Which of the following is true of her research subjects?
they have papillae on their toungues
