Bio 412 exam 1--> Quiz questions
What are adaptations?
inherited characteristics of organisms that enhance their survival and reproduction in specific environments
Sexual dimorphism is most often a result of
intersexual selection.
The most likely explanation for the high rate of sympatric speciation that apparently existed among the cichlids of Lake Victoria in the past is
sexual selection.
When using a cladistic approach to systematics, which of the following is considered most important for classification?
shared derived characters
Analogous features share ________ function but not ________ ancestry.
similar; common
Heterozygote advantage should be most closely linked to which of the following?
stabilizing selection
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation?
stabilizing selection
hpw do you do carbon dating
take the half-life and multiply it by however many half lives occured
A difficulty in presenting evidence for a sixth mass extinction is
that tropical rain forests harbor many unknown species
Whenever diploid populations are in Hardy-Weinberg equilibrium at a particular locus,
the allele's frequency should not change from one generation to the next, but its representation in homozygous and heterozygous genotypes may change.
Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?
the postzygotic barrier, reduced hybrid viability
According to the principle of maximum parsimony,
the preferred tree is the one that minimizes the amount of evolutionary change.
If two modern organisms are distantly related in an evolutionary sense, then one should expect that
they should share fewer homologous structures than two more closely related
When evolution occurred on the Galápagos Islands, the finch beaks
varied in size across the population and sometimes conferred benefits in feeding, survivorship, and reproduction that were passed down to surviving offspring.
What is the founder effect?
when a few individuals become isolated from a larger population and their gene pool differs from that source population
Macroevolution occurs
when reproductive barriers, either pre- or post-zygotic, genetically isolate species to the point where they no longer interbreed to produce viable offspring.
A species is represented by individuals that form a population
whose members have the ability to interbreed and produce viable, fertile offspring.
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms are applicable? 1. sympatric species 2. prezygotic isolation 3. postzygotic isolation 4. allopatric species 5. habitat isolation 6. reduced hybrid fertility
1 and 2 only
In a hypothetical situation, a certain species of flea feeds only on the blood of pronghorn antelopes. In rangelands of the western United States, pronghorns and cattle often associate with one another. If some of these pronghorn-feeding fleas develop a strong preference for cattle blood and mate only with other fleas that prefer cattle blood, then over time which of these should occur, if the host mammal can be considered as the fleas' habitat? 1. reproductive isolation 2. sympatric speciation 3. habitat isolation 4. prezygotic barriers
1 through 4
Assuming the phylogenetic tree shown is an accurate depiction of relatedness, then which of the following should be correct? 1. The entire tree is based on maximum parsimony. 2. If all species depicted here make up a taxon, this taxon is monophyletic. 3. The last common ancestor of species B and C occurred more recently than the last common ancestor of species D and E. 4. Species C is the direct ancestor of both species B and species D. 5. The species present at position 3 is ancestral to C, D, and E.
1,2,3
Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship.
2 → 4 → 1 → 3
If we visualize the time that has passed since the origin of our solar system and Earth, or about 4.6 billion years, as a one-hour clock, then out of one hour, humans have been present on the planet for about
2/10ths of a second.
If we visualize the time that has passed since the origin of our solar system and Earth, or about 4.6 billion years, as a one-hour clock, then out of one hour, prokaryotes have been present on the planet for about
45 minutes.
monophyletic
ALL descendants came from one common ancestor
Which of the following descriptions of polyploidy indicate speciation?
Allopolyploids mate with each other but cannot interbreed with parent species.
How can gene flow improve adaptation of population?
Beneficial alleles are transferred to a new population.
What is the benefit of using carbon in radioisotope dating, versus using other elements?
Carbon is central to nearly all molecules in living organisms, and its ubiquitous presence in the atmosphere, plus shorter half-life, provides accurate dating of especially recent samples.
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?
Characteristics acquired during an organism's life are not passed on through genes.
If organisms A, B, and C belong to the same class but to different orders, and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?
D and F
From the list below, select the correct format for the binomial (scientific name) of the species the monarch butterfly.
Danaus plexippus
Which of the following correctly describes, or is an example of, habitat isolation?
Members of the same species never come in contact due to a geographic barrier to interbreeding.
Which of the following statements is most accurate?
Geographic separation may result in biological barriers over time if populations of a species in the newly isolated regions undergo selective pressures that promote biological isolation and prevent successful reproduction if the species were to again come into contact later.
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago If a speciation event occurred on Sao Tomé, producing D. santomea from a parent colony of D. yakuba, then which of the following terms applies (apply)? I. macroevolution II allopatric speciation III. sympatric speciation
I and III
What is an example of what happens when herbivores switch to a new food source with different characteristics?
In populations that feed on goldenrain tree, natural selection results in beaks that are shorter than those in populations that feed on balloon vine.
Why is the Hardy-Weinberg model useful?
It allows you to calculate genotype frequencies of a population and compare them to what was expected under the assumptions
What must be true of any organ that is described as vestigial?
It must be homologous to some feature in an ancestor.
Which of the following is correct about genetic variation?
It must be present in a population before natural selection can act upon the population
Which statement about the atmosphere and life on Earth is correct?
Life on Earth arose before oxygen was present.
Does the number of branches on a tree determine how similar species are from each other?
No--> they share teh same common ancestor they just have more divergence
DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, today DDT is largely useless against many insects. Which of the following should have occurred for this pest eradication effort to be successful in the long run?
None of the individual insects should have possessed genomes that made them resistant to DDT.
Why don't similar genotypes always produce the same phenotype?
Phenotypes can vary depending upon environment
What evidence suggests that limbless bodies are the result of convergent evolution of snakes and lizards?
Snakes and lizards with limbless bodies evolved from different ancestors of legged lizards.
Within the past century, humans have been eating higher cholesterol and fatty meals and have become less physically active, which makes them more susceptible to heart disease. Which of the following will lead to an adaptation?
Some people's bodies are able to break down cholesterol and fat more efficiently than others.
Four relatively recent fossil species were recovered, and when the DNA was extracted, investigators observed that Species W and Z both had long finger bones, and species X and Y had short finger bones. Based upon this information and the hypothetical molecular data below, sequenced from common regions in one gene of their DNA, which two species are the most closely related to each other? Species W: AACATTGCTT TTGTAACGAA Species X: AACCGCGCGT TTGGCGCGCA Species Y: AGCAGCGCTT TCGTCGCGAA Species Z: AACCGCGCTT TTGGCGCGAA
Species X and Z
Phylogeny branch lengths represent genetic changes. Which organism on the tree has undergone the most genetic changes since divergence from common ancestor?
The one with the longest line
Which of the following is true of all horizontally oriented phylogenetic trees, in which time advances to the right?
The common ancestor represented by the rightmost branch point existed more recently in time than the common ancestors represented at branch points located to the left.
How is a scientific name written?
The genus is capitalized, and the whole name is in italics
A large community of rattlesnakes, from El Paso, Texas, is separated into two groups. One group is taken 46 miles northwest to Las Cruces, New Mexico. The other group goes 712 miles north to Estes Park, Colorado. Which of the following statements is most accurate?
The group moved to Estes Park will undergo a series of adaptations to survive
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
These bacteria should be outcompeted and replaced by bacteria that have lost these genes.
Members of two different species possess similar-looking structures that they use in a similar fashion to perform the same function. Which of the following statements describes these structures originating from convergent evolution?
These structures share function but do not share a common ancestry.
What is true of pseudogenes?
They are vestigial genes.
Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
A shared ancestral character is
a character that originated in an ancestor of two taxa.
Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon?
a variety of empty ecological niches, leading to adaptive radiation
Darwin's observation of the Galápagos Islands finches' various beaks and behaviors could be explained by
adaptations forged by natural selection.
Mountains also have an unmatched power to drive human evolution. Starting tens of thousands of years ago, people moved to high altitudes, and there they experienced natural selection that has reworked their biology. In Tibet, for example, people have broader arteries and capillaries. In the Andes, they can dissolve more oxygen into their blood. These different traits of people who live in high altitudes illustrate
adaptive evolution
Which event stimulated the rapid development of eukaryotes?
addition of oxygen to the atmosphere
"Conventional wisdom holds that the development of separate species happens quickly, most often when populations become separated by a geographical barrier." This is called ________ speciation. "Even if these groups meet again and manage to mate before diverging too far from one another, their offspring will be unfit and die out." This is described as hybrid ________.
allopatric; breakdown
The history of continental drift on Earth has
allowed for both speciation and extinction to occur.
Adaptive radiation
allows new species to occupy different habitats.
What does the Hardy-Weinberg equation asses?
an assessment of evolution at a particular locus
If you wanted to find the largest number of endemic species, you should visit which of the following geological features (assuming each has existed for several millions of years)?
an isolated ocean island in the tropics
Hawaii is the most southeastern of the seven islands and is also closest to the seafloor spreading center from which the Pacific plate originates, which lies about 5,600 km farther to the southeast. Assuming equal sedimentation rates, what should be the location of the thickest sediment layer and, thus, the area with the greatest diversity of fossils above the oceanic crust?
around the base of Kauai, the oldest of the Hawaiian Islands
You find a plant that is larger than others in your wheat field. When you examine the chromosomes of this plant during cell division, you observe that the cells have double chromosome numbers of the other wheat plants. You conclude this is an autopolyploid plant representing a new biological species in your wheat field when you observe
fertile tetrapods produced by self-pollinating.
Which of the following are the best examples of homologous structures?
bones in the bat wing and bones in the human forelimb
Of the following anatomical structures, which is homologous to the bones in the wing of a bird?
bones in the flipper of a whale
How did Mendel's model of inheritance help explain Darwin's theory of natural selection?
by proposing a mechanism of how organisms could transmit discrete, heritable units to offspring
Evolution of a gene
can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not met for that particular gene.
paraphyletic.
consists of an ancestral species and some, but not all, of its descendants
A potential source of confusion in constructing a phylogeny tree is similarity between organisms that is due to
convergent evolution
Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of
convergent evolution.
Radiometric dating is based on the
decay of radioactive isotopes.
In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?
directional selection
Imagine a male dragonfly is flying around in an aggressive pattern to find an appropriate mate in a wetland with many species of dragonflies and damselflies. Finally, he spots a female dragonfly that appears to be of the same species, based on her flight behavior and color, and the two mate. The sperm of the male, however, are unable to fertilize the eggs of the female when she lays them because her egg cell membrane proteins and carbohydrates do not recognize and bind to the male's sperm. This is an example of
gametic isolation.
Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing
gene flow
Which of the following must exist in a population before natural selection can act upon that population?
genetic variation among individuals
The Hardy-Weinberg equation p2 + 2pq + q2 = 1 allows you to calculate
genotype frequencies.
More species tend to be found in regions subdivided by rivers, canyons, mountains, or other human-induced barriers because of
geographic isolation.
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago. Using only the information provided in the paragraph, which of the following is the best initial hypothesis for how D. santomeadescended from D. yakuba?
habitat differentiation
In the formula for determining a population's genotype frequencies, the 2 in the term 2pq is necessary because
heterozygotes can come about in two ways based upon parental gametes.
Scientists discovered a fossil in China that belongs to a previously unknown species of an obscure group of small dinosaurs, related to primitive birds such as the famous Archaeopteryx. It had feathers, but they seemed too insubstantial to be useful in flight. Then the scientists said they recognized the unusually long, rodlike bone extending from each of the two wrists: curving structures possibly supporting an aerodynamic membrane. These scientists are grouping the found fossil with birds based on ________ structures.
homologous
The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because
humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.
Which of the following reproductive types of isolation illustrates postzygotic barriers?
hybrid breakdown
On the volcanic, equatorial West African island of Sao Tomé, two species of fruit fly exist. Drosophila yakuba inhabits the island's lowlands and is also found on the African mainland, located about 200 miles away. At higher elevations, and only on Sao Tomé, is found the very closely related Drosophila santomea. The two species can hybridize, though male hybrids are sterile. A hybrid zone exists at middle elevations, though hybrids there are greatly outnumbered by D. santomea. Studies of the two species' nuclear genomes reveal that D. yakuba on the island is more closely related to mainland D. yakuba than to D. santomea (2n = 4 in both species). Sao Tomé rose from the Atlantic Ocean about 14 million years ago. 1) Which of the following reduces gene flow between the gene pools of the two species on Sao Tomé, despite the existence of hybrids?
hybrid sterility
Lamarck's contribution to evolutionary theory was the
idea that evolutionary change explains patterns in fossils.
What is the result of adaptive evolution?
increase in frequency of alleles that provide reproductive advantage
Natural selection is based on all of the following except
individuals adapt to their environments and thereby evolve.
It is estimated by a wide body of scientists that in recent decades we have begun another mass extinction event on Earth. Amphibians in particular have been in decline, sometimes due to climate change, and they therefore provide a possible early sign of dramatic biodiversity change to come. With respect to climate change and natural selection acting upon a population of one species of frog in a tropical rain forest, mutations of DNA sequences of the frog genome that are inherited by offspring
may have no effect at all, be beneficial, or be harmful.
Which life form has been present on Earth the longes
microbes such as bacteria
You are an undergraduate student working with a graduate student in an entomology lab, and she presents you with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to help her separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?
morphological
Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in
mutations to homologous genes
Which of the following consistently improves the degree to which organisms are well suited for life in their environment?
natural selection
What is the Hardy-Weinberg equation?
p^2 + 2pq + q^2 = 1
polyphyletic
pertaining to a group of taxa derived from two or more different ancestors
Which of the following are problematic when the goal is to construct phylogenies that accurately reflect evolutionary history?
polyphyletic and paraphyletic taxa
Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). Consequently, the morphological similarities of these two species are probably due to
possession of analogous structures.
When hypothesizing a possible phylogeny in order to classify taxa, scientists incorporate systematics to
provide molecular or genetic information, as well as morphological information.
Sister taxa
represent groups of organisms that share an immediate common ancestor.
Of the following, which is the most abundant source of fossil evidence?
sedimentary rock, because such rock forms in areas sediment moved by water can cause the burial of organisms
Adult male humans generally have deeper voices than do adult female humans, which is the direct result of higher levels of testosterone causing growth of the larynx. If the fossil records of apes and humans alike show a trend toward decreasing larynx size in adult females and increasing larynx size in adult males, then
sexual dimorphism was developing over time in these species.
