Biol 322 Exam 4 (ch. 11-15, 18, 19, 20)

The apicoplast is an organelle found only in species in a phylum called Apicoplasta. This phylum includes a deadly human parasite, Plasmodium falciparum, which is responsible for malaria. Which of the following is NOT true regarding the apicoplast organelle?

There was only one endosymbiosis, which probably involved a large cyanobacteria engulfed by a protozoan cell, and they both developed second membranes for protection.

The leaf-cutter ant (Acromyrmex octospinosus) is one species of ant that participates in a beneficial mutualism with a fungal species. The female workers in the colony as well as the reproductive females are often covered with a thick whitish-gray coating, which turns out to be a bacterium that produces antibiotics. Which of the following is true regarding the function of these bacteria?

They produce antibiotics which kill parasites that grow in fungal gardens

Which of the following describes the phenetic species concept?

This concept looks at organisms that are clustered together in a phenotype space and is often used by numerical taxonomists

Fossils are the remains of past-living organisms that could form in several different ways. Which of the following describes fossilization by dissolution?

Water seeps into fossils and breaks it down, but the SHAPE of the fossil is preserved in the sediment around, leaving an image of the organism

Why did the human introduction of feral pigs on Santa Cruz Island accelerate the extinction of the native fox and increase the population of skunks?

a and b only (Increased pig numbers attracted the golden eagles, which is a fierce predator of foxes; skunks were the main prey of the island foxes)

mitochondrial eve

all above except the one with Y-chromosome Adam, I mean seriously, Y-chromosome Adam, who ever heard of such a thing (was an individual female who is a direct ancestor of all modern humans; presumably lived in a fairly large interbreeding population; was one of only many direct ancestors of modern humans in her generation)

Discrete ecological resources favor

all answers except "a single generalist species" (assortive mating by ecological resource type, disruptive selection, divergent specialist species)

In the case of California salamanders we can see how traits in one species (coloration of the toxic newts) influence the operation of selection on another (coloration of a nontoxic salamander). The following figure describes the actions of a predator, the western scrub-jay, that was provided with the opportunity to feed on live salamanders. Notice that Ensatina eschscholtzii oregonensis is a nontoxic and plain colored subspecies, a close relative of the mimic Ensatina eschscholtzii xanthoptica. Which of the following is true?

all of the above (Jays were very hesitant to approach E. e. xanthoptica, even though this salamander did not possess the neurotoxin found in the newts; After their first experience with the toxic California newts, the jays took more time to approach E. e. xanthoptica than E. e. oregonensis individuals; If such an encounter happens in the wild, the amount of time the scrub-jay hesitates could make the difference between survival and death for the E. e. xanthoptica.)

It is very difficult to find the fossil remains of the entire organism. Which of the following might be a factor for paleontologists to use when choosing sites to search for the best fossils?

all of the above (Paleontologists will typically focus on the sites that best match the geological and abiotic conditions in which fossilization may have occurred; Paleontologists are unlikely to be the first researcher to be searching for fossils from their organism of interest. Instead, they often choose sites where others have already uncovered related fossils; Paleontologists often use predictions derived from phylogenetic reconstruction, biogeography, or molecular genetics to explore a particular area.)

Galef and his colleagues have been studying the role of cultural transmission in the scavenging behavior of Norway rats (Rattus norvegicus). They wanted to find out if cultural transmission through social learning plays a role in rat foraging so they developed an experiment with observers (rats that did not have previous exposure to some foods) and demonstrators (rats that have experienced a new addition to their diet). Which of the following is true about this study?

all of the above (Rats with "cinnamon tutors" preferred cinnamon-flavored food; Rats with "cocoa tutors" preferred cocoa-flavored food; Cultural transmission from the demonstrators to observers was probably based on olfactory cues that observers picked up from demonstrators.)

Which of the following findings regarding the Midas and arrow cichlids in Lake Apoyo suggests that the speciation even responsible for forming these two species occured in sympatry rather than allopatry?

all of the above (The Midas and arrow sichlids are a monophyletic clade; Lake Apoyo is smalle, shallow, and homogeneous; Not even one mitochondrial haplotype was found in any other nicaraguan lake was the same as those found in the two Lake Apoyo species)

Which of the following is true regarding the evolution of chloroplasts?

all of the above (chloroplasts are derived from once free-living photosynthetic cyanobacteria; Cyanobacteria are related to algal plasts; RNA shows that the chloroplast of plants are closely related to cyanobacteria)

Which of the following are/is considered a type of heterochrony (changes in the rate and timing of development)?

all of the above (hypermorphosis, acceleration, neoteny)

The famous radiation of Galapagos finches from the common ancestor species on the Western coast of South America is probably a result of:

allopatric speciation (adaptive radiation too?)

During the 1990s Knowlton and colleagues studied pairs of sister species of the genus Alpheus (snapping shrimp). In each of these sister species pairs, members of one pair lived on the Caribbean side of the Isthmus of Panama, while members of the other pair lived on the pacific side. What type of speciation might be responsible for this speciation?

allopatric speciation with the dumbbell model (vicariance model)

In a study of two spruce species, red and black, scientists found that the red spruce was living in a smaller geographic area and had much less genetic variation that the black spruce. They proposed that the red spruce might have arisen from a southern population of black spruce, which became geographically isolated from other black spruce populations at some point during the Pleistocene glaciations. This is an example of:

allopatric speciation with the peripheral isolate model

Miller and Urey developed and conducted some experimental tests for a "prebiotic soup" model of the origin of life, which had been proposed a few decades earlier by Oparin and Haldane. What did Miller and Urey show could be synthesized abiotically?

amino acids

What type of coevolution produces an evolutionary arms race between a predator and its prey or a parasite and its host, which may go on indefinitely, producing a wide array of adaptations?

antagonistic coevolution

In all extinctions that have ever occurred on Earth, the majority of the lost species was due to:

background extinctions

In a hypothetical scenario, imagine that you have discovered a rare species of birds on a remote Pacific island. You spend some time studying their ecology and habitation and discover that although these birds look alike, there are indeed two distinct populations with very different mating calls. You propose that these two populations must be two species, since they no longer mate with one another. Which of the following species concepts would you use to defend your statement?

biological species concept

Genetic variation within modern humans indicates that:

both A and C (all modern humans have relatively recent African ancestry; that there were some small level of interbreeding between non-African modern humans and neanderthals)

Kellog (1896) and Fahrenholz (1909) both hypothesized that phylogenies of parasites and hosts often change in parallel. Why do we expect that?

both a and b ( When populations of a host species become geographically isolated from one another, the parasite populations that the host carries also become geographically isolated; If divergence in the host species is great enough and host speciation occurs, this can lead to speciation in the parasite as well.)

Evolutionary biologists are very interested in understanding the patterns and processes that guide the tempo and mode of evolution. In specific clades they are studying they sometimes point to trends (patterns of directional change over time). One such trend is also known as Cope's rule. Which of the following statements are true?

both a and b (Cope's rule states that species in mammalian clades tend to increase in body size over evolutionary time; Avian taxa appeared to follow Cope's rule throughout the Jurassic and Cretaceous periods.)

Which of the following is true of cultural transmission?

both a and b (Cultural transmission is the transfer of information from individual to individual through social learning or teaching; Cultural transmission is the system of information transfer that affects an individual's phenotype via social learning.)

The Hawaiian Islands have gone through at least two waves of human colonization (in prehistoric times and again starting in the seventeenth and eighteenth centuries). Of the approximately 125 to 145 bird species that once inhabited the Hawaiian Islands before human colonization, 90 to 110 are now extinct. Which of the following is most likely true when it comes to these extinctions?

both a and b (Early human colonization devastated the larger species of birds through hunting; Late human colonization devastated the natural habitats and food sources, such as flowers nectar and fruit of the native species)

Predator-prey interactions are one type of antagonistic coevolution. Which of the following traits would natural selection favor, in these interactions?

both a and b (Selection will favor traits in prey that increase the chance of escaping predation and traits in predators that increase their chance to capture and kill the prey; Selection on both participants will lead to an evolutionary arms race in which both predator and prey may evolve new traits.)

One of the gene duplications in developmental genes in plants, OEP16 is also known to arise along with neofunctionalization. Which of the following statements is true regarding these genes?

both a and b (The duplication in OEP16 gene took place in the lineage that led to the land plants; The neofunctionalization of the OEP gene may have been partly responsible for the explosion of plant diversity and the evolution of flowering land plants.)

The imperial blue butterfly (Jalmenus evagoras) and species of ant (Iridomyrmex anceps) have a mutualistic relationship in which the butterfly larvae and pupae secrete sugary nectar that nourishes the ants, while the ants protect the larvae and pupae from predators such as wasps. Which of the following statements describes the investments by both parties?

both a and b (This ant-butterfly mutualism involves a significant cost for the imperial blue butterfly. The larvae spend their resources on production of nectar, which leads to slower development and lower reproductive success; Ants involved in a mutualistic relationship with butterflies likely have an increased risk of detection by their own predators, as well as metabolic costs associated with defense of the butterfly larvae)

One of the main features of a eukaryotic cell is the nucleus. Recent evidence suggests that the cell nucleus may have evolved from archaeal ancestors and that the organelles may have evolved from bacterial ancestors, but there is another important factor that shaped the evolution of nuclear genomes. Which of the following is a source of the eukaryotic nuclear egenes?

both mitochondria and chloroplasts

Which of the following cases is an example of cospeciation?

both of the above (In molecular phylogenetic analysis of nuclear ribosomal DNA of Glochidion trees and Epicephala moths, speciation patterns appear to be very similar. In addition, each species cannot survive in the absence of the other; In comparing the phylogenies of lice and their hosts, there is an evidence of congruence between the hosts' and parasites' shared evolutionary history.)

What type of infectious disease is devastating populations of frogs in North America, Alaska, and Australia today?

chytridiomycosis, which interferes with the ability of amphibians to transport chemicals across the epidermis

Cryptic species

could be common in some taxonomic groups, so there might be a lot of biodiversity that has gone unnoticed

When we say that a cell is totipotent, we refer to a cell that:

could differentiate into any of the cell types that makes up the adult organism.

In a slime mold, Dictyostelium discoideum, single-celled individuals gather in the migratory slug stage of development, in response to environmental cues. Which molecule is associated with this signaling?

cyclic adenosine monophosphate

Speciation requires

divergence

Look at this definition of a species: "A species is a lineage of... populations which maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate." This definition best represents the:

evolutionary species concept

Which of the following molecules involved in membrane structure was likely favored by selection in the evolution of early cells?

fatty acids

In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of biological molecules. He mixed a number of different amino acids together at a high temperature (120 C) in an environment lacking water. When he subsequently placed the mixture into water to investigate what the amino acids would form he:

found some peptide-like structures, but the bonds between the amino acids were weak and unstable

Karl Ernst von Baer (1792-1876), German naturalist, biologist, and embryologist, rejected both the scala naturae and the Mackel-Serres law. Instead von Baer's law states that the:

general characteristics of embryos in closely related species develop before specific characteristics, and embryos of higher taxa do not resemble the adult form of ancestral lower-taxa species

Neural crest cells in vertebrates are cells that are initially positioned near the neural tube during early development and then migrate to new locations. The development and positioning of these cells is controlled by a set of:

homeotic genes (Hox, Snail, Dlx).

In the late 1800s William Bateson documented, both in insects and in vertebrates, many cases where one body part had replaced another, producing unusual forms. Bateson believed that his studies could teach us something about evolutionary changes. He named these changes:

homeotic transformations

Haldane's rule

implies an interaction between autosomes and sex chromosomes

Approximately when did mammals first evolve?

in the Mesozoic "Age of Reptiles"

Which of the following best represents the definition of an individual, as proposed by Michod?

integrated and indivisible wholes that can reproduce and pass heritable variations on to their offspring

reinforcement

is the idea that selection favors assortive mating because of the low fitness of hybrid individuals

All species concepts, at least in plants and animals, to some degree rely upon

minimal gene flow across taxa

There are thousands of different kinds of lichens, each of which is composed of one fungal species and one species of either photosynthetic algae or cyanobacteria. When species interact as fungi and algae do in lichen, so that the interaction of the two species increases the fitness of both species, this is called:

mutualism

Douc langurs are primates that have a diet of leaves instead of insects and fruit. In order to digest such food, these langurs use symbiotic bacteria in their gut and digest some of them using an enzyme associated with a gene known as RNASE. Gene duplication and the subsequent divergence of this gene, seems to be the genetic basis for its evolution. We could say that this is an example of:

neofunctionalization.

Heterochrony is well studied in amphibians. One of the famous examples is in a species of salamanders (Mexican axolotl), where reproductively mature individuals still live in the water and have external gills and flat tails, as in the salamander embryos. This phenomenon is best defined as:

neoteny

Which gas was most likely the least abundant in early Earth's atmosphere?

oxygen

When a reproductive trait appears earlier in development or when some somatic traits of an adult are retarded, we could define this type of development as:

paedomorphosis

Two common species of frogs from the genus Bombina (B. bombina and B. variegata) live in similar latitudes and ecological conditions, but in two different regions, Central and Eastern Europe. In a narrow strip between these regions, scientists observed a third species, which might have been a hybrid between the former divereging populations fo the ancestral species. What evolutionary process might be responsible for the speciation in Bombina?

parapatric speciation

In a hypothetical flowering plant species, one population evolves a different response to the environmental stimuli and began to bloom significantly later in the season than the nearby populations. What type of a reproductive isolating mechanism this would be?

prezygotic

In 1970, Lynn Margulis proposed that the origin of two eukaryotic organelles, mitochondria and chloroplasts, occurred through endosymbiosis. Which of the prokaryotic lineage is a phylogenetic candidate as the source of mitochondria?

proteobacteria

Paleontologists studies on a lineage of Bryozoan (whose fossils preserve many of the morphological characteristics) show a pattern of evolution with little or no change for long stretches of time. Occasionally however, speciation occurred in a burst of change and diversification. This is an example of:

punctuated equilibrium

Coevolutionary interactions with other living species often:

represents strong selection pressure and promotes specialization

Speciation requires divergence, typically caused by:

selection and Genetic Drift

In paleobiology one of the main concepts is that fossils found lower down in the sediment at a particular locality are older than those found closer to the surface. This is often called the law of:

superposition

In some species of fruit flies, males have black spots on the edge of their wings, which they use for visual displays during courtship dances with females, while in other species, these spots are completely absent. A gene called "yellow" plays a role in the development of these visual features in all of the species. The key to the differences in the amount and spatial distribution of the yellow protein is due to?

the effects of regulatory enhancers on the yellow gene

Which of the following is not a major transition in the evolution of life, based on Maynard Smith and Szathmary (1997)?

the formation of the solar system including Earth

The word "speciation" as usually used by classical evolutionary biologists (not just rebels) means...

the origin of intrinsic (not merely geographic) reproductive isolating barriers

The phylogenetic species definition says...

the smallest monophyletic group distinguishable by at least one synapomorphy

All of the following is true regarding Spiegelman's experiment on the origins of life EXCEPT that:

there was no selection for any of the variations in length

Australopithecus

were bipedal

How long ago did the mitochondrial eve live, and where?

150,000 years and Africa

Among the oldest fossils on Earth are the microfossils from the Agnes gold mines of South Africa, which are ______ years old

3.2 billion

Radiocarbon dating (14C) is a useful tool for measuring absolute time for about ___________ years.

50,000

Thyroid hormone (TH) has been identified as one of the factors promoting phenotype development in the Mexican salamander, or axolotl. All of the following statements regarding the impact of TH are true EXCEPT:

Adding thyroid hormone (T4) to the water in which axolotl individuals were reared causes them to remain in a larval stage.

Lice are often obligate parasites on specific hosts, and because of such close associations; they are often used in studies of species interaction and coevolution. One such example involves lice on pigeons and doves, where phylogenetic studies uncovered eight cospeciation events. What drove their evolution in this host-parasite system?

After a speciation event occurs in a pigeon or dove, lice are constrained to remain on their host species because they often fare poorly when switching hosts.

Which of the following statements is true about Hox genes experiments?

All of the above (Homeobox regions of the Hox genes allow one species' transcription factor to function in the other species; When the mouse Hox-2.2 gene is experimentally inserted into the fruit fly genome and expressed in the head of developing fruit flies, adults produce legs in place of antennae.; When a Hox gene product from an appropriate chromosomal region in chickens was inserted into a fruit fly embryo, it resulted in normal regulation of the fruit fly development.)

In order to understand the origin of life on Earth, evolutionary biologists collaborate with:

All of the above (chemists, geologists, atmosphere scientists)

The famous K-T extinction occurred about 65 million years ago, at the boundary of the Cretaceous and Tertiary periods, with profound effects on many different taxa, including the dinosaurs. Which is the widely accepted as the cause of this extinction?

An impact with an extraterrestrial body, such as an asteroid, as evidenced by the layer of clay demarcating the Cretaceous-Tertiary boundary which contains iridium.

Young marsupials are born underdeveloped and with a number of adaptations to the life in mother's pouch. One adaption is particularly important for their survival, since it enables the jaw structures to suckling mother's milk at this early stage of development. What changes in the neural crest development are responsible for this?

Analysis of marsupial embryos found that neural crest cells begin their migration much earlier in marsupials than in other mammal groups and this promotes early jaw development.

One of the first studied Hox gene mutations in Drosophila was a mutation in the Antennapedia (Ant) gene, which controls leg formation. This mutation is abbreviated as Antp. What is the phenotypic effect of this mutation?

Antennae are replaced by legs.

In the cliff swallows it is common to find a blood-sucking parasite, an insect known as the swallow bug. This bug often clings to the feet of birds, can move freely from swallow to swallow within colonies, and it is responsible for most nest failures and juvenile mortality. The following graph shows a correlation between the colony size and the number of bugs per nest. What conclusion(s) can you make, based on this study?

As group size increases, the cost of parasitism increases

In some species of animals that are preyed upon, we can find evidence of mimicry or false visual signals to their predators suggesting that the prey is most likely unpalatable. One example is a species of Ensatina salamanders that mimics a sympatric species of toxic newts (Taricha torosa). What type of mimicry is this?

Batesian mimicry

Two parapatric subspecies of sagebrush (mountain big sagebrush and basin big sagebrush) produce hybrid sagebrush, which is often found in the intermediate elevation. In the following graph below, you can see germination early survival rates for each of them raised in three different environments (1.800 meters, above 1,900 meters, and in the hybrid zone between). Which of the following best explains the findings in this experiment?

Both a and b (The hybrid individuals had lower fitness in environments below 1,800 m and above 1,900 m, but a higher fitness than either subspecies when all types were raised in the hybrid zone; These results provide support for the bounded hybrid superiority model)

The human parasite Mycoplasma genitalium, withone of the smallest genomes of any organism that can be grown, as well as Chlamydia trachomatis, an obligate intracellular parasite, are examples of the type of organisms that functional genomics researchers have focused on. What is the main purpose of the study of such genomes.

By studying such genomes, researchers try to discover the basic and essential cellular functions of early life

Look in the three graphs below, showing three different types of evolutionary change in a hypothetical clade. The y-axis represents time, while the x-axis represents a character (body size, in this example). which of the following graphs represents an active evolutionary trend?

C

In light of recent achievements in the field of genomics, would it be reasonable to expect that the use of comparative genomics might shed light on the extinct genomes of early life?

Comparative genomics and studies of the bacteria with very small genomes do shed light on a common ancestor and researchers can estimate the minimal characteristics that a cell would need to operate as a living organism

What is the most relevant hypothesis for the benefit of making the switch from the RNA- to a DNA-based genetic system during the evolution of life?

DNA is a more stable molecule because deoxyribose is less reactive than is ribose

The figure above illustrates

Dobzhansky-Muller incompatibility (figure says negative epistasis)

The Dobzhansky-Muller model explains hybrid infertility in crosses between two close species (such as the fruit flies D. simulans and D. melanogaster). Which of the following is the best explanation of this model?

Epistatic interactions between the alleles of two or more loci, undergoing different evolutionary paths in the two speciating groups, lead to the fitness costs of hybridization

A number of evolutionary studies show a strong phylogenetic link between prokaryotic and eukaryotic cells. Which of the following is the best statement about the evolutionary origins of eukaryotic cells?

Eukaryotic "informational" genes are closely related to Archaea, while their "operational" genes are closely related to Bacteria

Rivera and Lake's analysis (2004) suggests that ancient eukaryotic cells emerged from the fusion of an archaeal cell (most likely from the phylum Eocyta) and a bacterium. Which of the following is correct regarding this phylogenetic working hypothesis?

Eukaryotic cells probably evolved through endosymbiosis, in which either the archaeal or bacterial cell was engulfed with the other

Which of the following is NOT true regarding the evolution of group living?

Group living provides many benefits, but it does not improve foraging (finding food)

What do we know about horizontal gene transfer (HGT) in the evolution of early life?

HGT was probably a powerful force during early cell evolution, leading to complex cellular organisms

Define homeotic genes.

Homeotic genes are "master-switch" genes that control other genes in a set sequence and thereby affect cell size, shape, division, and the positioning of the cells within the organism.

What would be an appropriate evolutionary explanation of the fact that the ordering of some homeotic genes (e.g., Hox genes) on vertebrate chromosomes parallels the ordering of homeotic genes on fruit fly chromosomes?

Homeotic genes display ancient homologies.

In the early 1980s, studies in fruit flies led to discovery of the master-switch genes involved in animal development. Which of these genes are essential for the development of different body segments of fruit flies?

Hox genes

Based on the abundant fossil records, only 10,000 years ago, two-thirds of the 150 genera of the Pleistocene megafauna that were present 40,000 years earlier had gone extinct. What seems to be the reason for this relatively recent extinction of so many large mammal species

Hunting by humans, habitat fragmentation, and the ice age played a large role in this extinction

Which of the following defines Haldane's rile and its predictions?

If among hybrid offspring one sex is absent, rare, or sterile, that sex is heterogametic.

Which of the following statements best explains secondary reinforcement?

If the reproductive isolating mechanisms that developed during the geographic isolation are somewhat weak but the hybrids between two population have lower fitness, then the speciation process may continue

The woodland star-Greya politella moth system is a good example of mosaic coevolution in nature. The moth lays its eggs into developing flowers of the woodland star and the plant pays a cost for this, because moth larvae eat some of its seeds. In addition, this moth is a sole pollinator of the woodland star flowers in some geographic locations, while in other locations woodland star has additional pollinators. Which of the following statements is NOT true regarding mosaic coevolution in this example?

In all studied locations the woodland star rarely aborted flower capsules that contained moth eggs (doing so would also kill the moth larvae), compared to capsules that had no moth eggs.

A fossil of an organism with some features intermediate between older and younger fossil organisms

Is a potentially informative transitional form, even if it is not on a direct line of descent between the other fossils

Which of the following statements about LUCA is NOT correct?

It is meant to be a single organism

Which of the following is correct regarding the endemic species as a model for the study of background extinctions?

Its is much easier to study extinction in endemic species because such local extinctions become synonymous with global extinction

Biologists have documented asexual reproduction in some animal lineages. Even in some vertebrates, such as reptiles, some species reproduce only with parthenogenesis (development from unfertilized eggs). However, parthenogenesis has never been documented in mammals. What is the current genetic explanation for this difference between mammals and other vertebrates?

Mammals evolved a process of genetic imprinting and therefore some genes from father's genomes need to be expressed.

What is the meaning of the phrase "dead clade walking," which was coined by Jablonski in 2002?

Many of the remaining clades that survived a period of mass extinction go extinct during the following geological time period

Which of the following statements regarding complexity of living organisms is NOT correct?

Natural selection necessarily entails an increase of complexity over evolutionary time

The origin of cell structures might be hypothesized to have involved a hypercycle, based on mutualism at the molecular level. Which of the following is correct regarding the hypercycle model?

Natural selection will favor a hypercycle that is enclosed in a membrane

Which two scientists elaborated on Darwin's idea of the "warm little pond" and formulated the "prebiotic soup hypothesis" as the first hypothesis for the abiotic origin of life on earth?

Oparin and Haldane

As opposed to background extinction, a mass extinction typically refers to the loss of many groups of organisms over a broad geographic range. Which of the following mass extinction in Earth's geological history was the most devastating for the marine families?

Permian

Jablonski and his coworkers found that, for slugs and snails (gastropods) of the Late Cretaceous period, the key to a broad geographic range at the species level and increased chances of surviving the mass extinction at the K-T boundary was the nature of the larval stage. Which of the following best describes a stage that contribute to the increased geographic ranges of the gastropod taxa?

Planktotrophic larvae that feed in the open water on very small prey and develop into adults at a relatively slow pace

The first genetic material was most likely:

RNA

Slime molds are unusual eukaryotes. They spend most of their life cycle as single-celled organisms and yet, under certain conditions, they form a slug-like multicellular stage and then a fruiting body composed of both somatic cells and reproductive spores. The best known species of slime mold is a soil dweller, Dictyostelium discoideum. Why is it important to study this and related species of slime molds?

Slime molds provide hints as to how multicellularity may have evolved.

Which of the following examples would be the best match for the statement? "individuals give up the ability to reproduce independently, and they join together to form a larger grouping that shares reproduction."

Solitary individuals started living together in colonial groups, sometimes even giving up the possibility of independent replication, as we see in many species of social insects.

Soybean legumes are involved in a mutualistic relationship with rhizobial bacteria (B. japonicum) in which bacteria converts inorganic nitrogen in the root nodules of the plant into an organic form of nitrogen that the plants uses as a resource for its own growth and synthesis. In experiments with a nitrogen-free atmosphere, bacteria are forced to be "the cheaters." Which of the following was not found in these experiments?

Soybean plants did not have an ability to respond to reduced nitrogen fixation by B. japonicum in a way that would reduce cheating.

Deep homology of homeotic genes is also seen in plants. For example, the MADS-box genes have been used to work out phylogenetic relationships within flowering species of plants. What was also documented in these studies across many plant lineages?

The MADS-box genes are also instrumental in nonflowering plant species, where they are involved in developmental pathways in leaf and root systems.

Which of the following is true for the ancient Greek view of ontogeny (the development of an individual over its lifetime), which was later developed as the concept of "scala naturae" (or the "great chain of being") in the European natural sciences?

The ancient Greeks argued that the ontogeny of an individual was built up from simple traits in early development to more complex traits later in the developmental process

In the common bluegill sunfish, foraging in small groups increases success in finding food. They feed on small, aquatic insects that live in underwater vegetation and when bluegills forage together they are able to flush out many more insects. Which of the following is correct in this case of group foraging?

The bluegill example illustrates a "passive" benefit of group foraging

Ernst Haeckel (1834-1919), a German biologist and naturalist, disagreed with von Baer and further expanded on the Meckel-Serres law with his biogenetic law. What does the biogenic law claim?

The developmental progress of an organism (its ontogeny) recapitulates its evolutionary history (its phylogeny)

If a gene is affected by many regulatory enhancers, what would be an important evolutionary implication?

The enhancers can increase morphological variation and hence the amount of variation that natural selection has to act on.

Over the last few decades, there has been a major decline in amphibian populations worldwide, including the extinction of many amphibian species. Which of the following is NOT true regarding the amphibian decline?

The extinctions seem to be due to the increased predation of the amphibians around the world.

Define a regulatory enhancer of a gene.

The regulatory enhancer is a section of DNA that lies outside of that gene but is involved in regulating the timing and level of that gene's expression.

Which of the following statements about the Lincoln and Joyce experiment on self-replicating ribozymes is most likely correct?

The self-replicating ribozymes that had more efficient catalytic activities would soon began to dominate their populations

Peter and Rosemary Grant wanted to test both genetic and cultural transmission hypothesis by comparing the songs of sons to those of their paternal and maternal grandfathers. Their results are shown in the following figure. Which of the following conclusions is the best fit for the results?

The son's song resembles the song of the paternal grandfather but not the song of the maternal grandfather, indicating that birdsong appears to be culturally transmitted.

Which of the following is true regarding speciation in Rhagoletis pomonella (the apple maggot fly)?

The sympatric races of the apple maggot fly are indeed diverging, and potentially on the path to becoming separate species.

Which of the following is NOT true regarding the evolution of multicellularity?

The transition from unicellular to multicellular life occurred only once in evolutionary history, giviing rise to all multicellular organisms today

Many species of mammals and birds alike are known to live in close communities, while other species live solitary lives. What do we know about the benefits of sociality?

There is often a significant positive correlation between group size, such as, for instance, colony size in birds and survival rate of the population

In 1997, Lutzoni and Pagel compared the rate of nucleotide substitution in free-living versus mutualistic fungi, in order to test a hypothesis that coevolution could promote the rate of molecular evolution in participating species. Which of the following was not supported by their results?

There was a more rapid rate of molecular evolution in the free-living fungi (related to the species that lives in lichens), than in the mutualistic species