Evolution final exam

150,000; mtDNA

Homo neanderthalensis and possible immediate predecessors were present in Europe and central Asia from around 300,000 years and lived there until about 35,000 years ago. Homo sapiens appeared in Africa roughly ____ years ago. The first studies of ___ from a number of Neanderthal bone fragments, and also from bones of ancient Homo sapiens of approximately the same age, did not give evidence of interbreeding, but also did not rule out the possibility that limited interbreeding had taken place. Later genomic studies gave evidence of limited interbreeding (for example, from Homo neanderthalensis to Eurasian populations of Homo sapiens as a result of interbreeding that took place in the Near East sometime within the past 100,000 years).

a. Neanderthals were heavier, stronger, and more stocky, with more pronounced brow ridges and larger eyes. FEEDBACK: A Neanderthal skull is very easily distinguished from modern humans due to its pronounced brow ridges and larger eye sockets. Although physically different from modern humans, Neanderthals shared a great deal culturally. These two species were closer than previously thought, as newer evidence indicates there was interbreeding between them. Read the subsection titled "From Homo heidelbergensis to Modern Humans" in Section 19.3 and compare the skulls of Homo neanderthalensis and Homo sapiens in Figure 19.28.

How did Homo neanderthalensis differ from Homo sapiens morphologically? Select one: a. Neanderthals were heavier, stronger, and more stocky, with more pronounced brow ridges and larger eyes. b. Neanderthals were heavier, stronger, and taller, with less pronounced brow ridges and smaller eyes. c. Morphologically, Neanderthals were virtually the same except they had larger brow ridges. d. Neanderthals were shorter, lighter, and more stocky, with more pronounced brow ridges and smaller eyes.

c. Hominins leave Africa and colonize the rest of the Old World a single time as Homo ergaster. Homo ergaster populations in different parts of the world diverge morphologically but do not speciate. Eventually, they evolve into Homo heidelbergensis and then modern humans. FEEDBACK: The multiregional hypothesis suggests that hominins left Africa and colonized the rest of the Old World once, going from multiple populations of Homo ergaster into Homo heidelbergensis and then modern humans. This model essentially predicts that humans of particular geographic locations are descended from premodern hominins from that same geographic location, while the out-of-Africa hypothesis predicts that all modern humans are descended only from premodern hominins in Africa. Read the subsection titled "Models for the Evolution of Modern Humans" in Section 19.3 and examine Figure 19.27A (the figure shown).

How is hominin radiation depicted by the multiregional hypothesis? Select one: a. Hominins leave Africa and colonize the rest of the Old World in multiple waves, establishing multiple populations of Homo ergaster. Eventually, they evolve into Homo heidelbergensis and then modern humans. b. Hominins leave Africa and colonize the rest of the Old World multiple times as Homo erectus. Homo erectus populations in different parts of the world diverge morphologically but do not speciate. Eventually, they evolve into Homo heidelbergensis and then modern humans. c. Hominins leave Africa and colonize the rest of the Old World a single time as Homo ergaster. Homo ergaster populations in different parts of the world diverge morphologically but do not speciate. Eventually, they evolve into Homo heidelbergensis and then modern humans. d. Hominins leave Africa and colonize the rest of the Old World multiple times as Homo erectus. Homo erectus populations in different parts of the world diverge morphologically but do not speciate. Eventually, they evolve into Homo heidelbergensis and then modern humans.

5 million

Humans are included in the Hominoidea superfamily, or the apes, all of which are Old World species. The next group that Hominoidea shares the most recent common ancestor with is the Old World monkey, and finally the New World monkey. Although a great deal is known about hominin migration and interbreeding, there is still a large gap in information around our divergence from chimpanzees approximately _____ years ago.

c. chimpanzees (Pan) FEEDBACK: Within the Hominoid superfamily, humans are most closely related to the two species of chimpanzee—the common chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). Gorillas are more distantly related, orangutans even more so, while gibbons are the most distant from humans. Read the beginning of Section 19.1 titled "Evolutionary Relationships among the Great Apes."

Humans are part of a superfamily known as the Hominoidea. This clade, also known as the apes, consists of eight living genera. Which of the following genera share a more recent common ancestor with humans than the others? Select one: a. orangutans (Pongo) b. gorillas (Gorilla) c. chimpanzees (Pan) d. gibbons genera

cooperation; Defection

If both subjects want to minimize the lengths of their prison sentences, each should defect and agree to testify against his codefendant. The seemingly intractable problem that the prisoners face is that once taken to their separate interrogation rooms, each has no way to ensure that the other will cooperate if he does so himself—and in fact by the logic above, each has every reason to suspect the other will defect instead. So, why would we ever see cooperative behavior in games that take the form of the prisoner's dilemma? In one- shot games—that is, in circumstances in which the game is played only once—the answer is that we do not expect to see ____. _____ is a Nash equilibrium (neither player can benefit by changing his strategy and cooperating), and it is the only Nash equilibrium.

parallel

If the association between two species is very close, they may speciate in _____. This is called cospeciation. It is especially likely to happen between parasites and their hosts. There are many examples of cospeciation in the living world, such as in trees from a genus Glochidion, which depend on the Epicephala moths for pollination. At the same time, the moths are fully dependent on their flowers for nutrients. Another common example is coevolution between parasitic lice and their various hosts. By comparing the phylogenies of different lice species and their hosts, we can assess the congruence between the hosts' and parasites' shared evolutionary history.

a. The only Nash equilibrium is defection; neither player can benefit by changing his strategy and cooperating.

If the prisoner's dilemma game is played only once, what would we expect to see? Select one: a. The only Nash equilibrium is defection; neither player can benefit by changing his strategy and cooperating. b. We would expect to see cooperation. c. We would expect to see one player testify (defect) and one player refuse to testify (cooperate). d. A mixed Nash equilibrium would arise.

a. 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.

In 1997, François Lutzoni and Marc 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? Select one: a. 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. b. The rates of nucleotide substitution were higher in fungal species involved in mutualistic relationships with algae and liverworts than the rates in the closely related, free-living fungal species. c. The increased rate of nucleotide substitution occurred only during or after the transition to the mutualistic relationship. d. The increased rate of nucleotide substitution in mutualistic species was widespread across many sections of the genome.

0.5; 0.5; 0.5 x 0.5 = 0.25

In Figure 17.3A, individuals A and B are half siblings, with the same mother but different fathers. To compute the coefficient of relatedness r between individuals A and B, we first must find the most recent common ancestor or ancestors. In this case, there is one most recent common ancestor—their mother. Second, we compute the probability that a given allele copy in the mother is passed to both offspring. The probability is ____ that the allele will be passed to individual A, and the probability is ___ that it will be passed to individual B, so the probability that it will be passed to both is ___ × ___ = ____. Because the mother is the sole most recent common ancestor, this is the total coefficient of relatedness r.

high; low

In Hamilton's rule, when the coefficient of relatedness r is high, benefit b to the recipient is ___, and cost c to the actor is ___, then natural selection should strongly favor individuals who help their kin.

b. A particular allele somehow distorts the process of segregation in its own favor, meaning it increases its representation in the gametes and thus becomes favored by selection.

In competition within a genome, one of the interesting evolutionary interactions at the gene level is caused by the segregation distorters, or meiotic drive alleles. This has been observed in Drosophila, mice, and some other species. Meiotic drive may be observed when which of the following occurs? Select one: a. One chromosome has a high incidence of recombination compared to other chromosomes. b. A particular allele somehow distorts the process of segregation in its own favor, meaning it increases its representation in the gametes and thus becomes favored by selection. c. A sex chromosome of one or the other sex is silenced with a gene in the opposite sex genome. d. A chromosome becomes duplicated.

c. Batesian mimicry

In some species of prey animals, we can find evidence of mimicry, or false visual signals to predators suggesting that the prey is most likely unpalatable. One example is a nontoxic species of Ensatina salamanders that mimics a sympatric species of toxic newts (Taricha torosa). What type of mimicry is this? Select one: a. aposematic mimicry b. Müllerian mimicry c. Batesian mimicry d. Mertensian mimicry

mutualistic; antagonistic; antagonistic

In terms of the long-term evolutionary dynamics of coevolution between species, two basic types of interactions—_____ and ______—seem to drive the evolutionary changes. In the case of _____ coevolution, evolutionary changes in each species decrease the fitness of the other species, resulting in an evolutionary arms race to combat that fitness decline.

antagonistic

In the _____ interactions between predator and prey, natural selection favors any trait that increases the chance of getting ahead in the evolutionary arms race. When a new trait facilitating escape evolves in prey, this immediately intensifies selection on predators for traits that increase their probability of capturing and consuming this better-adapted prey. Such a trait in predators will then favor any trait in prey that allows them to escape even better, and so on, in an ongoing coevolutionary dynamic.

d. There was no significant difference in the behavior of the jays after being exposed to either the nontoxic salamander or the toxic newt.

In the case of California salamanders, we can see how traits in one species (coloration of the toxic newts) influence selection on another (coloration of a nontoxic salamander). The figure describes the actions of a predator, the Western scrub jay, which was provided with the opportunity to feed on live salamanders. Note 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 NOT true about the behavior of the Western scrub jays? Select one: a. The jays were very hesitant to approach E. e. xanthoptica, even though this salamander did not possess the neurotoxin found in the newts. b. After their first experience with the toxic California newts, the jays took more time to approach E. e. xanthoptica than E. e. oregonensis individuals. c. If such an encounter happens in the wild, the amount of time the jays hesitate could make the difference between survival and death for the E. e. xanthoptica. d. There was no significant difference in the behavior of the jays after being exposed to either the nontoxic salamander or the toxic newt.

a. 0.25

In the figure, individuals A and B are half siblings, with the same mother but different fathers. What is the coefficient of relatedness r between individuals A and B? Select one: a. 0.25 b. 0.50 c. 0.75 d. 0.125

suppress

In the leaf-cutter ant (Acromyrmex octospinosus), which is involved in an ant-fungus mutualism, the thick coating on the worker is composed of bacteria that produce antibiotics that ____ the growth of parasites in the fungal garden. These antibiotics specifically protect the fungi they grow, and there is strong evidence that selection has favored the use of the Streptomyces bacteria by the ants (Mangone and Currie 2007). They do not have an effect on other parasites in the ant colony, and so do not affect ant eggs or larvae directly.

a. In all studied locations, the woodland star rarely aborted flower capsules that contained moth eggs, compared to capsules that had no moth eggs.

Interactions between the herbaceous plant Lithophragma parviflorum (also known as the woodland star) and the moth Greya politella serve as a good example of mosaic coevolution in nature. The moth lays its eggs into developing flowers of the woodland star, but the plant pays a cost for this because moth larvae eat some of the woodland star's seeds. In addition, this moth is the sole pollinator of the woodland star's flowers in some geographic locations, while in other locations, the woodland star has additional pollinators. Which of the following statements is NOT true regarding mosaic coevolution in this example? Select one: a. In all studied locations, the woodland star rarely aborted flower capsules that contained moth eggs, compared to capsules that had no moth eggs. b. In populations where alternative pollinators were present, the woodland star selectively aborted flower capsules that contained moth eggs because the costs of having the moth pollinator outweighed the benefits, and selection favored an antagonistic response. c. In cases where the moth was the sole pollinator for the plant, the woodland star rarely aborted flower capsules that contained moth eggs because the benefits of having the moth pollinator outweighed the costs, and selection favored mutualism. d. The moth Greya politella is completely reliant on the woodland star as its host, but the woodland star is not always reliant on the moth as its sole pollinator.

social punishment

It is interesting that paper wasps can recognize when signals are not honest based on the other wasp's facial pattern and behavior. As the experiment showed, these signals are kept honest by ____. If a paper wasp exhibits facial patterns indicating dominance (and high fighting ability) but in reality is not a fighting type, the other wasps will react with increased aggression toward that wasp.

chimpanzees

It is often difficult to place fossils definitively in the hominin lineage when they date close to the divergence with ______. In the case of Ardipithecus ramidus, although it had a gripping opposable toe, its face was much flatter than a chimpanzee face.

d. Rats routinely chose the food that was not given to their tutors as a means to monopolize a food source that was not being exploited.

Jeff Galef and his colleagues have studied 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 had experienced a new addition to their diet). Which of the following is NOT true about this study? Select one: a. Rats with "cinnamon tutors" preferred cinnamon-flavored food. b. Rats with "cocoa tutors" preferred cocoa-flavored food c. Cultural transmission from the demonstrators to observers was probably based on olfactory cues that observers picked up from demonstrators. d. Rats routinely chose the food that was not given to their tutors as a means to monopolize a food source that was not being exploited.

mosaic coevolution; antagonistic relationship

John Thompson and Bradley Cunningham studied ____ in interactions between the herbaceous plant Lithophragma parviflorum (woodland star) and the moth Greya politella (Thompson and Cunningham 2002). In four populations in which G. politella acted as the sole pollinator and the woodland star was the sole host for G. politella, Thompson and Cunningham found a mutualistic relationship between plants and moths. In these populations, 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. In four other populations in which the woodland star had numerous pollinators besides G. politella, they found evidence of an _____ between plants and moths in which the plants selectively aborted flower capsules that contained moth eggs.

a. When populations of a host species become geographically isolated from one another, the parasite populations that the host carries also become geographically isolated, leading to potential divergence of both species.

Kellogg (1896) and Fahrenholz (1909) both hypothesized that phylogenies of parasites and hosts often change in parallel. Why do we expect that? Select one: a. When populations of a host species become geographically isolated from one another, the parasite populations that the host carries also become geographically isolated, leading to potential divergence of both species. b. When populations of a host species become geographically isolated from one another, the parasite populations have to adapt to new hosts, and this usually leads to speciation in the parasite as it adapts. c. When populations of a parasite species become geographically isolated from one another, divergence results in speciation of the parasite species with subsequent colonization of new host species. d. When geographically isolated, both species experience divergence leading to a reduction in parasite load in the former host species as it becomes less habitable to the parasite.

a. 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.

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 coevolution in this host- parasite system? Select one: a. 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. b. When speciation changes the size of their natural host, lice may opt to live on a new host, which is a different size than their original host. c. Studies have proposed that there are benefits to lice if they stay on size-matched species, with small lice living on large host species and larger lice on small host species. d. After speciation of the host, lice often switch to smaller hosts to maintain the size match that enables them to avoid preening by the host.

mutualistic fungi; mutualism

Lutzoni and Pagel compared 1550 nucleotide sites in 16 species of mutualistic fungi and 13 species of free-living fungi that are closely related to the mutualistic species found in lichens (Lutzoni and Pagel 1997). They found that there was a much more rapid rate of molecular evolution in the ____, especially in those involved in relationships with algae and liverworts. The researchers also found evidence consistent with the hypothesis that the transition to _____ was responsible for accelerating the rate of molecular evolution. The increased rate of nucleotide substitution occurred only during and after the transition to the mutualistic relationship, not before. They also found that the increased rate of nucleotide substitution in mutualistic species was not restricted to one specific area of the genome, but rather was widespread across many sections of the genome.

d. It indicates that A. ramidus was at least partially arboreal, or living in or among the trees. FEEDBACK: It is often difficult to place fossils definitively in the hominin lineage when they date close to the divergence with chimpanzees. In the case of Ardipithecus ramidus, although it had a gripping opposable toe, its face was much flatter than a chimpanzee face. Read the subsection titled "The First Hominins" in Section 19.2.

Many of the first hominins had small cranial capacity and some capacity for upright locomotion. The foot morphology of Ardipithecus ramidus, an early hominin, had a gripping opposable toe. What does this suggest about its locomotion? Select one: a. It indicates that A. ramidus was primarily bipedal but still used its feet for gripping food. b. It indicates that A. ramidus was more closely related to chimpanzees than modern humans. c. It is not an indicative characteristic to determine the primary mode of locomotion. d. It indicates that A. ramidus was at least partially arboreal, or living in or among the trees.

d. Old World monkeys Humans are included in the Hominoidea superfamily, or the apes, all of which are Old World species. The next group that Hominoidea shares the most recent common ancestor with is the Old World monkey, and finally the New World monkey. Although a great deal is known about hominin migration and interbreeding, there is still a large gap in information around our divergence from chimpanzees approximately 5 million years ago. Review Figure 19.4.

Members of the Hominoidea most recently shared a common ancestor with which group? Select one: a. New World apes b. Lemurs c. New World monkeys d. Old World monkeys

c. Natural selection operates at two levels—within the group and between groups.

Modern trait-group models specify the circumstances in which selection can favor group-beneficial traits even when such traits impose individual-level costs. Which of the following is TRUE for a trait-group selection model? Select one: a. Natural selection operates only within the group. b. Natural selection operates only between the groups. c. Natural selection operates at two levels—within the group and between groups. d. Natural selection operates at three levels—within the group, between groups, and among different species.

diffuse coevolutionary

Mutualistic relationships provide benefits to the species involved. This _____ relationship involves a web of mutualisms between three species; Dichanthelium lanuginosum depends on Curvularia protuberata, and Curvularia depends on the CThTV virus to live in the geothermally heated soils of Yellowstone National Park. The loss of CThTV would result in the loss of Curvularia, which would result in the loss of Dichanthelium in this highly specialized environment.

lower reproductive success; indirect

Naomi Pierce and her colleagues studied a mutualistic relationship between the imperial blue butterfly (J. evagoras) and a species of ant (I. anceps) (Pierce et al. 2002). The butterfly larvae and pupae secrete sugary nectar composed of sucrose and fructose that nourishes the ants, while the ants protect the larvae and pupae from predators. Larvae can use the nutrients normally provided to ants for their own development. Since size in both male and female butterflies is related to reproductive success, pupating early in the wild leads to _____ for the butterflies, and hence it represents a significant investment. Ants also experience a cost, although it is _____. By protecting the butterfly larvae, they have an increased risk of detection by their own predators and parasitoids. In addition, they bear metabolic costs that are associated with defense of the butterfly larvae.

c. diffuse coevolution

Panic grass (Dichanthelium lanuginosum) can live in geothermally heated soils only when the fungus Curvularia protuberata is present. In order for Curvularia protuberata to colonize the soil, the Curvularia thermal tolerance virus (CThTV) must also be present. This web of coevolutionary interactions between multiple species is referred to as __________. Select one: a. antagonistic coevolution b. intraspecific coevolution c. diffuse coevolution d. cultural coevolution

a. The cultural part of the transmission occurs when the son learns the song from the father. The gene part is a result of females mating only with males who sing the song typically produced by males of their own species, greatly reducing between-species mating.

Peter and Rosemary Grant have studied the gene-culture transmission of birdsong in Charles Darwin's finches, Geospiza fortis and Geospiza scandens. What evidence from their studies illustrates the "culture" part of the transmission and what evidence illustrates the "gene" part of this coevolutionary relationship? Select one: a. The cultural part of the transmission occurs when the son learns the song from the father. The gene part is a result of females mating only with males who sing the song typically produced by males of their own species, greatly reducing between-species mating. b. The cultural part of the transmission occurs when females mate only with males who sing the song typically produced by males of their own species, greatly reducing between-species mating. The gene part is a result of sons learning the song from their fathers. c. The gene part of the transmission occurs when the song is genetically inherited from the father. The cultural part occurs when females choose to mate with males of their own species based on their song, greatly reducing between-species mating. d. The cultural part of the transmission occurs when females teach their sons the song. The gene part occurs when females mate only with males of their own species, identifying them based on their song and reducing between-species mating.

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

Peter and Rosemary Grant tested both genetic and cultural transmission hypotheses by comparing the songs of sons to those of their paternal and maternal grandfathers in two finch species, Geospiza fortis and Geospiza scandens. Their results are shown in the figure. Which of the following conclusions is the best fit for the results? Select one: a. The son's song resembles the song of both the paternal grandfather and maternal grandfather, indicating that the birdsong is genetically transmitted. b. The son's song resembles the song of the paternal grandfather but not the song of the maternal grandfather, indicating that the birdsong appears to be culturally transmitted. c. The son's song resembles the song of the paternal grandfather but not the song of the maternal grandfather, indicating that the birdsong is genetically transmitted. d. The son's song is most similar to the song of the maternal grandfather, indicating that the birdsong is transmitted via the X-linked chromosomes.

a. Natural selection will favor traits in prey that increase the chance of escaping predation and traits in predators that increase their chance of capturing and killing prey, resulting in an evolutionary arms race.

Predator-prey interactions are one type of antagonistic coevolution. Which of the following traits would natural selection favor in these interactions? Select one: a. Natural selection will favor traits in prey that increase the chance of escaping predation and traits in predators that increase their chance of capturing and killing prey, resulting in an evolutionary arms race. b. Natural selection will only favor those traits that help prey escape predation, resulting in an evolutionary arms race. c. Natural selection will only favor those traits that help predators capture their prey, resulting in a cessation of an evolutionary arms race. d. Natural selection will favor traits that help the prey species and negatively impact the predator species.

2.3 million

Recent fossil evidence suggests that one or more of the archaic hominin species fashioned stone tools and used them when scavenging for meat. A large number of such tools have been dated to 2.5 million to 2 million years ago. Approximately ____ years ago, the first members of the genus Homo appeared. These first species were Homo habilis and the similar, if somewhat larger, Homo rudolfensis, as well as the so-called premodern hominins that were the immediate ancestors to Homo sapiens.

d. stable groups, with ongoing interactions with the same set of partners

Reciprocal altruism can be best explained with a model proposed by Robert Trivers in 1971. Trivers hypothesized that if one individual (A) pays some cost to help another individual (B), but the cost is recovered at some point in the future (when B helps A), then natural selection might favor behaviors that lead to this type of reciprocity. In which of the following situations is reciprocal altruism likely to occur? Select one: a. dynamic large populations where individuals rarely interact with the same set of partners b. eusocial groups such as termites, ants, and other such species c. large populations of marine invertebrates d. stable groups, with ongoing interactions with the same set of partners

E. e. xanthoptica; E. e. oregonensis

Shawn Kuchta and his team of researchers first presented a Western scrub jay with a toxic California newt (Taricha torosa), and then they presented the jay with either the mimic salamander Ensatina eschscholtzii xanthoptica, or an individual from the closely related subspecies Ensatina eschscholtzii oregonensis, which is visibly similar to E. e. xanthoptica except that it lacks orange and yellow coloration (Kuchta et al. 2008). After experience with the toxic California newts, some of which the jays attacked, the jays took more time to approach _____ than _____ individuals.

cultural transmission

Smelling another rat provides olfactory cues about what it has eaten. This transfer of information from one rat to another about safe foods is a form of ____.

c. Soybean plants did not have an ability to respond to reduced nitrogen fixation by the rhizobial bacterium in a way that would reduce cheating.

Soybean, which are legumes (Glycine max), are involved in a mutualistic relationship with rhizobial bacteria (Bradyrhizobium japonicum) in which the bacteria convert inorganic nitrogen in the root nodules of the plant into an organic form of nitrogen that the plant uses as a resource for its own growth and synthesis. In experiments within a nitrogen-free atmosphere, the bacteria are forced to be "the cheaters." Which of the following was NOT a finding of these experiments? Select one: a. Populations of rhizobial bacteria grew larger in plant nodules when nitrogen was present in the atmosphere, versus in a treatment in which the atmosphere was nitrogen-free. b. Soybean plants changed the permeability of the nodule membranes, curtailing the oxygen available to bacteria, which in turn reduced the growth rate of the rhizobial bacterium. c. Soybean plants did not have an ability to respond to reduced nitrogen fixation by the rhizobial bacterium in a way that would reduce cheating. d. Rhizobial bacteria can survive without fixing nitrogen, but the lack of organic nitrogen creates a cost for the soybean plants.

b. Yes, because rb - c > 0 In the example, r (between full siblings) = 0.5, c = 0.2, and b = 0.5. Therefore, rb - c > 0 and we would expect the allele to increase in frequency.

Suppose that an allele is present in pelican offspring that causes a nestling to share its food with its nestmate if it is not particularly hungry. This gene imposes a fitness cost of 0.2 on those who carry it, while conferring a benefit of 0.5 on the sibling who receives the additional food. Will this gene increase in frequency if two nestmates are always full siblings? Select one: a. Yes, because rb - c < 0 b. Yes, because rb - c > 0 c. No, because rb - c > 0 d. No, because rb - c < 0

b. Researchers were able to sequence the entire Denisovan genome from the single finger bone. FEEDBACK: As an example of the success of modern DNA technology, the entire genome of this species was sequenced from this single bone fragment. That information was coupled with information from the Neanderthal and modern human genomes to provide tremendous insight to the relationships between recent hominins. Read the subsection titled "From Homo heidelbergensis to Modern Humans" in Section 19.3.

The Denisovan group is known from a single finger bone and a couple of teeth discovered in the Altai mountains. Despite the scant fossil evidence, we know a large amount of information about the Denisovans. Why? Select one: a. There were detailed cave drawings where the bone and teeth were found, which provided a tremendous amount of information about the Denisovans. b. Researchers were able to sequence the entire Denisovan genome from the single finger bone. c. Modern forensic science techniques enabled forensic morphological reconstruction from limited fossil material. d. Tools found at the site provided context for the fossils, which enabled archaeologists to reconstruct a substantial amount of information about Denisovan culture.

multiregional; out-of-Africa

The ____ hypothesis suggests that hominins left Africa and colonized the rest of the Old World once, going from multiple populations of Homo ergaster into Homo heidelbergensis and then modern humans. This model essentially predicts that humans of particular geographic locations are descended from premodern hominins from that same geographic location, while the ____ hypothesis predicts that all modern humans are descended only from premodern hominins in Africa.

structure algorithm

The _____ is extremely useful for distinguishing ancestral origin when analyzing a large number of loci at the same time. By revealing admixture, researchers get a more accurate picture of a population and the relationship to neighboring geographic regions, which also helps to provide a more accurate picture of migratory patterns.

Homo sapiens

The _____ species is the only surviving member of a clade that included many other species. Unfortunately, even though many other species have been identified from fossil remains, the information needed to resolve phylogenetic histories is very limited. New technologies that have enabled researchers to sequence ancient DNA have added a tremendous amount of information, including whole-genome analysis for Neanderthals.

social learning; gene flow

The compilation of data from the Grants' studies of Darwin's finches have provided biologists tremendous insight to evolutionary processes. Here, the finches' behavior is influenced by ____ when male finches learn birdsong from their fathers and that learned birdsong influences the behavior of potential mates. This results in females that mate only with males who sing the song recognized as being produced by males of their own species. The behavior of the male finches directly influences ____ by reinforcing mate choice behavior of the females in the population.

social organization changes

The dramatic bottleneck in the Y chromosome data is especially striking given that the X chromosome data indicate an effective population size 17 times larger than that of the Y chromosome. This time period of about 10,000 years ago saw an increase in the variance of male reproductive success. Monika Karmin and her colleagues speculated that this was a result of _____ that came with the advent of agriculture, perhaps in concert with wars of conquest.

b. It was likely a consequence of a dramatic increase in variance in male reproductive success during this time period, likely as a result of change in human social organization. FEEDBACK: The dramatic bottleneck in the Y chromosome data is especially striking given that the X chromosome data indicate an effective population size 17 times larger than that of the Y chromosome. This time period of about 10,000 years ago saw an increase in the variance of male reproductive success. Monika Karmin and her colleagues speculated that this was a result of social organization changes that came with the advent of agriculture, perhaps in concert with wars of conquest. Read the subsection titled "Gene Trees for Modern Human Populations" in Section 19.5 and examine Figure 19.35 (the figure shown).

The estimated effective population size for humans indicated there was a significant bottleneck in the patrilineally transmitted Y chromosome, but there was not a bottleneck revealed in the matrilineally transmitted X chromosome. What is the most likely reason for this? Select one: a. It is indicative of a disease outbreak that specifically reduced the male population, leading to differential male success in reproduction. b. It was likely a consequence of a dramatic increase in variance in male reproductive success during this time period, likely as a result of change in human social organization. c. It was likely a consequence of more males migrating out of Africa than females, leading to greater reproductive success for females. d. The bottleneck in the Y chromosome data represents an artifact of incomplete data sets used in the analysis.

bipedal locomotion

The evolution of ____ offered several advantages for early hominins, including being more energetically efficient than the knuckle-walking gaits of chimpanzees, exposing less surface area to the direct rays of the sun, and freeing the hands from locomotion so that they could be used for carrying items or gathering fruit.

d. evolutionary arms race

The fossil record of the Sinistrofulgur-Mercenaria system shows that selection has favored an increased shell size and shell thickness in Mercenaria prey, which reduced the probability of it being eaten by Sinistrofulgur. Subsequently, the fossil record indicated there was an increase in size of Sinistrofulgur; larger Sinistrofulgur were more likely to be able to kill Mercenaria. What type of coevolutionary dynamic does this illustrate? Select one: a. diffuse coevolution b. Batesian mimicry c. mosaic coevolution d. evolutionary arms race

a. The butterfly larvae spend their resources on production of nectar, which leads to slower development and lower reproductive success. The ants have an increased risk of detection by predators and metabolic costs associated with defense of the butterfly larvae.

The imperial blue butterfly (Jalmenus evagoras) and a species of ant Iridomyrmex anceps have a mutualistic relationship that is costly to both species but also provides benefits to both. Which of the following statements correctly describes the investment by both parties? Select one: a. The butterfly larvae spend their resources on production of nectar, which leads to slower development and lower reproductive success. The ants have an increased risk of detection by predators and metabolic costs associated with defense of the butterfly larvae. b. The ants spend their resources on production of nectar, which leads to slower development and lower reproductive success. The butterfly larvae have an increased risk of detection by predators and metabolic costs associated with defense of the ants. c. Although both species experience metabolic costs as a result of the relationship, it is insignificant when compared to the benefits they receive. d. Butterfly larvae attended by the ants tend to be much larger, leading to early pupation and lower reproductive success, although more of them survive. The ants have an increased risk of predation while tending the butterfly larvae.

a. They produce antibiotics that kill parasites that grow in the fungal gardens.

The leaf-cutter ant (Acromyrmex octospinosus) is one species of ant that participates in a beneficial mutualism with a fungal species. The female workers as well as the reproductive females in the colony are often covered with a thick whitish-gray coating, which turns out to be bacteria that produce antibiotics. Which of the following is TRUE regarding the function of these bacteria? Select one: a. They produce antibiotics that kill parasites that grow in the fungal gardens. b. They produce antibiotics that kill parasites in the ant eggs and larvae. c. They produce antibiotics that protect the adult ants, improving their reproduction. d. They produce antibiotics that kill both parasites that grow in the fungal gardens and those in the ant eggs and larvae.

Homo heidelbergensis

The out-of-Africa hypothesis suggests that hominins left Africa and colonized the rest of the Old World in multiple waves. Homo sapiens ultimately evolves from _____ in Africa and spreads worldwide, replacing the resident hominins. ____ also gives rise to the Neanderthals and Denisovans in Europe.

50%; 50%

The process of meiotic segregation occurs once per generation. Thus, for any given allele copy in the parent, there is a ____% chance that this allele will be passed on to each offspring and a ____% chance that the homologous allele will be passed on instead.

cooking hypothesis

The reduced nutritional challenge, possibly resulting from switching from raw to cooked foods, may have resulted in significant morphological changes in modern humans that altered the course of evolution. Anthropologist Richard Wrangham's _____ suggests that many of the morphological changes that modern humans underwent were associated with the acquisition of fire technology. The ability to cook food meant that food was easier to chew and had larger energy stores that were easier to consume and digest. Additional nutrition also may have led to the increase in female body mass observed during this time period.

populations; allele frequencies

The structure algorithm has been very successful in assigning individuals to ____ and inferring ____ for each population. The primary reason is that small allele frequency differences among populations can together distinguish ancestral origin if a sufficiently large number of loci are considered at the same time.

c. mutualism

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 __________. Select one: a. parasitism b. antagonism c. mutualism d. speciation

93-95%

To the surprise of many, human population groups are not genetically distinct despite fairly obvious differences in features. Additionally, there are very few alleles that are uniquely diagnostic of a particular geographic region. Recent statistical evidence indicates that within- population variation comprises ___% to ___% of total human variation.

more slowly

Toby Kiers and her colleagues conducted an experiment with reduced nitrogen and found that soybean plants in the nitrogen-free treatment did indeed respond to Bradyrhizobium japonicum failing to fix nitrogen (Kiers and Denison 2008). In the nitrogen-free environment, even in a split-root experiment, rhizobial bacteria populations grew significantly _____. Although rhizobial bacteria can survive without fixing nitrogen, the lack of organic nitrogen creates a cost for the plant. Soybean root cells react to the lack of these nutrients by changing the permeability of the nodule membranes and curtailing the oxygen available to bacteria. The lack of oxygen significantly reduces the rhizobial bacteria growth rate and the size of the nodules. Read how coevolution may lead to mechanisms that would prevent "cheating" in mutualistic relationships, such as between rhizobial bacteria and legume plant roots, in the subsection titled "Mutualism and the Response to Cheaters" in Section 18.1.

a. individuals can be ascribed partial ancestry from multiple source populations FEEDBACK: The structure algorithm is extremely useful for distinguishing ancestral origin when analyzing a large number of loci at the same time. By revealing admixture, researchers get a more accurate picture of a population and the relationship to neighboring geographic regions, which also helps to provide a more accurate picture of migratory patterns. Read the subsection titled "Multilocus Studies of Population History" in Section 19.5 and examine Figure 19.37.

Use of the structure algorithm helps to reveal patterns of human migration patterns across major geographic regions. It can also uncover admixture, which means __________. Select one: a. individuals can be ascribed partial ancestry from multiple source populations b. regions can be ascribed partial ancestry from multiple source populations c. alleles can be ascribed partial ancestry from multiple source populations d. species can be ascribed partial ancestry from multiple source populations

Segregation distorters, or meiotic drive alleles

We expect that, on average, half the gametes produced by a heterozygote at a given locus will contain one allele at that locus and half the gametes will contain the other allele. But if a particular allele could somehow distort the process of segregation in its own favor (that is, if it could increase its representation to more than half the gametes produced by an individual), all else being equal, that allele would be favored by selection. These are called _____.

d. Homo ergaster leaves Africa and becomes Homo erectus in Asia; Homo heidelbergensis evolves in Africa from Homo ergaster and spreads into Europe where the Neanderthal/Denisovan lineage branches off; Homo sapiens evolves from Homo heidelbergensis in Africa and spreads worldwide, replacing resident hominins. FEEDBACK: The out-of-Africa hypothesis suggests that hominins left Africa and colonized the rest of the Old World in multiple waves. Homo sapiens ultimately evolves from Homo heidelbergensis in Africa and spreads worldwide, replacing the resident hominins. Homo heidelbergensis also gives rise to the Neanderthals and Denisovans in Europe. Read the subsection titled "Models for the Evolution of Modern Humans" in Section 19.3 and examine Figure 19.27B (the figure shown).

What are the hominin radiations depicted in this figure, which illustrates the out-of-Africa hypothesis? Select one: a. Homo ergaster leaves Africa and becomes Homo sapiens; Homo heidelbergensis evolves in Asia from Homo ergaster and spreads into Europe where the Neanderthal/Denisovan lineage branches off; Homo sapiens evolves from Homo heidelbergensis in Western Eurasia, Africa, and the Middle East, and spreads worldwide. b. Homo erectus evolves in East Asia and Australasia; Homo ergaster evolves in Africa and becomes Homo erectus in Asia; Homo sapiens evolves from Homo heidelbergensis in Africa and spreads worldwide, replacing resident hominins. c. Homo ergaster leaves Africa and becomes Homo erectus in Asia; Homo sapiens evolves from Homo heidelbergensis and Homo erectus and spreads worldwide, replacing resident hominins. d. Homo ergaster leaves Africa and becomes Homo erectus in Asia; Homo heidelbergensis evolves in Africa from Homo ergaster and spreads into Europe where the Neanderthal/Denisovan lineage branches off; Homo sapiens evolves from Homo heidelbergensis in Africa and spreads worldwide, replacing resident hominins.

c. bipedal locomotion FEEDBACK: The evolution of bipedal locomotion offered several advantages for early hominins, including being more energetically efficient than the knuckle-walking gaits of chimpanzees, exposing less surface area to the direct rays of the sun, and freeing the hands from locomotion so that they could be used for carrying items or gathering fruit. Read the beginning of Section 19.2 titled "The Hominin Clade."

What became the most important adaptation for hominins that moved out of the African forest onto the savannah? Select one: a. loss of large canine teeth b. a shift in the foramen magnum c. bipedal locomotion d. early development of language for communication between hunting parties

b. It assumes that the set of genotypes under consideration comes from some specified number of distinct groups, each with its own characteristic allele frequencies. FEEDBACK: The structure algorithm has been very successful in assigning individuals to populations and inferring allele frequencies for each population. The primary reason is that small allele frequency differences among populations can together distinguish ancestral origin if a sufficiently large number of loci are considered at the same time. Read the subsection titled "Multilocus Studies of Population History" in Section 19.5.

What is the primary assumption of the structure algorithm? Select one: a. It assumes that the set of genotypes under consideration comes from an infinite number of groups; it then sorts the data into a defined number of groups, each with its own characteristic allele frequencies. b. It assumes that the set of genotypes under consideration comes from some specified number of distinct groups, each with its own characteristic allele frequencies. c. It assumes that each individual genotype under consideration has characteristic allele frequencies and uses that to sort the data into a defined number of groups. d. It assumes that the set of genotypes under consideration does not represent any characteristic allele frequencies, and then sorts those genotypes into distinct groups.

c. 1% to 4% at the individual level of non-Africans, 20% to 30% total FEEDBACK: As a result of their research into interbreeding between Neanderthals and modern humans, Richard Green and his colleagues did indeed discover that non-African modern humans retain 1% to 4% of Neanderthal DNA, despite the fact that many Neanderthal-derived alleles seem to have deleterious consequences (Green et al. 2010). Overall, they estimated that a remarkable 20% to 30% of Neanderthal DNA can be found in the human population, although a single individual will not have anywhere near that amount. Different populations appeared to have retained different alleles via selection. Read the subsection titled "Interbreeding with Neanderthals" in Section 19.4.

What percentage of Neanderthal DNA do modern, non-African humans have at the individual level, and how much total Neanderthal DNA can be found in the entirety of the human genome? Select one: a. 4% to 8% at the individual level of non-Africans, 15% to 18% total b. 0.05% to 1.4% at the individual level of non-Africans, 2% to 5% total c. 1% to 4% at the individual level of non-Africans, 20% to 30% total d. 20% to 30% at the individual level of non-Africans, 50% to 58% total

b. antagonistic coevolution

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? Select one: a. mutualistic coevolution b. antagonistic coevolution c. cospeciation d. none of these

c. 2.3 million years ago FEEDBACK: Recent fossil evidence suggests that one or more of the archaic hominin species fashioned stone tools and used them when scavenging for meat. A large number of such tools have been dated to 2.5 million to 2 million years ago. Approximately 2.3 million years ago, the first members of the genus Homo appeared. These first species were Homo habilis and the similar, if somewhat larger, Homo rudolfensis, as well as the so-called premodern hominins that were the immediate ancestors to Homo sapiens. Read the subsections titled "The Archaic Hominins" and "The Genus Homo" in Section 19.2.

When did the first members of the genus Homo appear? Select one: a. 100,000 years ago b. 1 million years ago c. 2.3 million years ago d. 3.5 million years ago

speciation

When populations of a host species become geographically isolated from one another, this will often produce geographic isolation among the parasite populations that the host carries. As the host populations diverge, selection acts in new ways, not only on individuals in the host populations, but also on the respective parasite populations they carry. If divergence in the host species is great enough and host speciation occurs, this can lead to _____ in the parasite as well (Moran and Baumann 1994; Wade 2007).

codependency

When species interact, as fungi and algae do in lichen, the action of natural selection on one species may cause selection to operate in new ways on the other. The ____ between algae and fungi is so complete that, for most lichens, neither the fungal nor the algal species can survive in the absence of its partner. This type of interaction of the two species, which increases the fitness of both species, is called mutualism.

a. decrease in female body mass FEEDBACK: The reduced nutritional challenge, possibly resulting from switching from raw to cooked foods, may have resulted in significant morphological changes in modern humans that altered the course of evolution. Anthropologist Richard Wrangham's cooking hypothesis suggests that many of the morphological changes that modern humans underwent were associated with the acquisition of fire technology. The ability to cook food meant that food was easier to chew and had larger energy stores that were easier to consume and digest. Additional nutrition also may have led to the increase in female body mass observed during this time period. Read the subsection titled "The Genus Homo" in Section 19.2.

Which morphological change would NOT be associated with a reduced nutritional challenge for modern humans? Select one: a. decrease in female body mass b. decrease in size of the jaw and molars c. decrease in size of the digestive tract d. significant increase in brain size

a. In a 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.

Which of the following cases is an example of cospeciation? Select one: a. In a 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. b. Panic grass, Dichanthelium lanuginosum, cannot live in geothermally heated soils without the fungus Curvularia protuberata. c. Jalmenus evagoras larvae cannot survive without the ant Iridomyrmex anceps. The ants also receive food from the nectar provided by the butterfly larvae. d. The leaf-cutter ant, Acromyrmex octospinosus, harbors bacteria that produce antibiotics that prevent the growth of parasites in the fungal gardens they cultivate.

c. Cultural transmission is the transfer of information between individuals of the same age class, affecting genotypic ratios within that age class.

Which of the following is NOT true of cultural transmission? Select one: a. Cultural transmission is the transfer of information from individual to individual through social learning or teaching and affects an individual's phenotype. b. Cultural transmission is the transfer of information from parent to offspring through social learning and impacts the phenotypic ratios of the overall population. c. Cultural transmission is the transfer of information between individuals of the same age class, affecting genotypic ratios within that age class. d. Cultural transmission is the transfer of information between relatives within the same family group, which affects the phenotype of the next generation.

d. A limited amount of variation has been passed from Homo neanderthalensis to Eurasian populations of Homo sapiens as a result of interbreeding that probably took place in the Near East at some point within the past 100,000 years. FEEDBACK: Homo neanderthalensis and possible immediate predecessors were present in Europe and central Asia from around 300,000 years and lived there until about 35,000 years ago. Homo sapiens appeared in Africa roughly 150,000 years ago. The first studies of mtDNA from a number of Neanderthal bone fragments, and also from bones of ancient Homo sapiens of approximately the same age, did not give evidence of interbreeding, but also did not rule out the possibility that limited interbreeding had taken place. Later genomic studies gave evidence of limited interbreeding (for example, from Homo neanderthalensis to Eurasian populations of Homo sapiens as a result of interbreeding that took place in the Near East sometime within the past 100,000 years).

Which of the following is TRUE regarding the possible interbreeding between the human and Neanderthal species? Select one: a. There is no evidence of hybridization between Neanderthals and modern humans. Both bone mtDNA and genomics studies ruled out such interbreeding. b. Neanderthals share a common ancestor with humans about 250,000 years ago. Both species originated in Africa and migrated to Europe and Asia about 100,000 years ago. c. Modern humans are more closely related to Neanderthals than to early Homo sapiens since there was extensive interbreeding between humans and Neanderthals about 35,000 years ago. d. A limited amount of variation has been passed from Homo neanderthalensis to Eurasian populations of Homo sapiens as a result of interbreeding that probably took place in the Near East at some point within the past 100,000 years.

b. A plant species that adapts to cold climates at high elevation.

Which of the following relationships is NOT an example of coevolution? Select one: a. Monarch butterfly larvae that feed only on milkweed plants that are not toxic to the monarch larvae but toxic to other animals; the butterflies provide pollination for the milkweed plants. b. A plant species that adapts to cold climates at high elevation. c. The mutualism between fungi and algae that form lichen species. d. Ants that live in the thorns of Acacia trees; the trees provide a home for the ants while the ants protect the trees from other predators.

b. larger brain FEEDBACK: Homo naledi was an incredible fossil find, the remains of which were located deep in a South African cave system. Researchers concluded the skeletal remains were placed there deliberately, possibly as a crude form of burial. The remains were very nearly complete and undisturbed by predators or scavengers. The discovery is so new that their age had not yet been determined at the time this text was published! Although they share many characteristics with the Homo genus, their brains were small, no bigger in fact than that of Australopithecus. Read the subsection titled "The Genus Homo" in Section 19.2 and see Figure 19.24 (the figure shown).

Which of the following was NOT a characteristic of Homo naledi that was also shared with the rest of the Homo genus? Select one: a. dexterous hands b. larger brain c. feet adaptated for upright walking d. reduced jaw and teeth

c. All species in the clade are extinct except for one, and there is very limited information about the other species. FEEDBACK: The Homo sapiens species is the only surviving member of a clade that included many other species. Unfortunately, even though many other species have been identified from fossil remains, the information needed to resolve phylogenetic histories is very limited. New technologies that have enabled researchers to sequence ancient DNA have added a tremendous amount of information, including whole-genome analysis for Neanderthals. Read the beginning of Section 19.2 titled "The Hominin Clade."

Why has it been so difficult to resolve the phylogenetic history of the hominin clade? Select one: a. There are too many species to determine significant differences; morphological data are not definitive due to the high degree of similarity. b. Researchers can only use fossil evidence and that has not been enough to resolve the nature of the relationships between the species. c. All species in the clade are extinct except for one, and there is very limited information about the other species. d. Researchers only have limited information on very few species in the clade, and the species do not appear to overlap with each other.

common chimpanzee; bonobo

Within the Hominoid superfamily, humans are most closely related to the two species of chimpanzee—the _____ (Pan troglodytes) and the ____ (Pan paniscus). Gorillas are more distantly related, orangutans even more so, while gibbons are the most distant from humans.

Homo naledi

____ was an incredible fossil find, the remains of which were located deep in a South African cave system. Researchers concluded the skeletal remains were placed there deliberately, possibly as a crude form of burial. The remains were very nearly complete and undisturbed by predators or scavengers. The discovery is so new that their age had not yet been determined at the time this text was published! Although they share many characteristics with the Homo genus, their brains were small, no bigger in fact than that of Australopithecus.

Reciprocal altruism

_____ might be favored by natural selection among individuals that live in stable groups because they are likely to have ongoing interactions with the same set of partners.

Coevolution; coevolution

_____ occurs when the action of natural selection on one species causes natural selection to operate in new ways on the other species. This is a result of a deep, integrated relationship between the two species. In the example of the prairie dog, the warning call will help alert other prairie dogs to the presence of the predator, but there is not a direct change in how natural selection operates on the coyote, therefore this is not an example of ____.

Hamilton's rule

_____ shows that the extent to which natural selection favors assisting family members depends on how closely related individuals are to one another and how high or low the associated costs and benefits turn out to be. When the coefficient of relatedness r is high, benefit b to the recipient is high, and cost c to the actor is low, then natural selection should strongly favor individuals who help their kin.

interbreeding

A Neanderthal skull is very easily distinguished from modern humans due to its pronounced brow ridges and larger eye sockets. Although physically different from modern humans, Neanderthals shared a great deal culturally. These two species were closer than previously thought, as newer evidence indicates there was ____ between them.

Within-group ; within-group; between-group

A group in which all individuals affect one another's fitness is called a trait group. The essence of trait-group selection models is that natural selection operates at two levels—within-group selection and between-group selection. ____ selection acts against cooperators who pay some cost that others do not. Selfish individuals are always favored by ____ selection since they receive any benefits that accrue because of the actions of cooperators. On the other hand, ____ selection favors cooperation if groups with more cooperators outproduce other groups (such as by producing more total offspring or being able to colonize new areas faster).

Sinistrofulgur-Mercenaria system

Adaptations seen in this predator-prey relationship clearly illustrates an evolutionary arms race. The evolution in prey of the ability to avoid a predator is followed by selection of predators that can successfully capture the modified prey. This cycle can continue and indeed leave evidence in surviving species after the relationship ends with the extinction of one of the participant species.

polymorphism

Although it is clear that modern humans are most closely related to chimpanzees, we share a closer relationship with gorillas at approximately 20% of our loci. This could be the result of a _____ that was maintained after the species diverged or could be a result of deep coalescence, also known as incomplete lineage sorting.

c. 0.75

Ants, bees, and wasps are haplodiploid species. What is the coefficient of relatedness (r) between two female workers in the same nest that were sired by the same drone (father)? Select one: a. 0.125 b. 0.50 c. 0.75 d. 1.00

0.25; 0.5

Ants, bees, and wasps are haplodiploid; that is, all males are haploid and all females are diploid. Because of the genetics of haplodiploidy, when a queen in a colony mates with a single male, sister workers are related to one another on average by a coefficient of relatedness r of 0.75; that is, the probability that a given parental allele ends up in both sisters is 0.75. The probability that the sisters share a given allele copy through their mother is ____ (as in the case of diploid species), but because all males are haploid, the probability that sisters share an allele copy through their father is ___. Adding these probabilities gives us our genetic relatedness value of 0.75 for full sisters.

Batesian mimicry; Müllerian mimicry

Aposematic coloration is a warning color that predators can perceive and remember as associated with toxicity of the prey. This is quite common in salamanders and many other animals. In Ensatina eschscholtzii xanthoptica salamanders, orange body color and yellow eyes appear to be the result of coevolution with a toxic California newt, Taricha torosa, which lives sympatrically with E. e. xanthoptica populations. This sort of mimicry, in which one species is palatable and the other is not, is called _____. On the other hand, _____ refers to cases when multiple species evolve similar phenotypes to reinforce warning signals.

human population; single individual

As a result of their research into interbreeding between Neanderthals and modern humans, Richard Green and his colleagues did indeed discover that non-African modern humans retain 1% to 4% of Neanderthal DNA, despite the fact that many Neanderthal-derived alleles seem to have deleterious consequences. Overall, they estimated that a remarkable 20% to 30% of Neanderthal DNA can be found in the ____, although a ____ will not have anywhere near that amount. Different populations appeared to have retained different alleles via selection.

The Denisovans

As an example of the success of modern DNA technology, the entire genome of this species was sequenced from this single bone fragment. That information was coupled with information from the Neanderthal and modern human genomes to provide tremendous insight to the relationships between recent hominins.

a. gorillas FEEDBACK: Although it is clear that modern humans are most closely related to chimpanzees, we share a closer relationship with gorillas at approximately 20% of our loci. This could be the result of a polymorphism that was maintained after the species diverged or could be a result of deep coalescence, also known as incomplete lineage sorting. Read the beginning of Section 19.1 titled "Evolutionary Relationships among the Great Apes."

At the majority of loci, humans are more closely related to chimpanzees than any other living species. However, at about 20% of our loci, humans are more closely related to __________ than chimpanzees. Select one: a. gorillas b. gibbons c. orangutans d. capuchins

c. r = 0.125 To calculate the coefficient of relatedness (often denoted r) between two individuals (you and your first cousin), we must locate your most recent common ancestor or ancestors (assume that those are your common grandparents). Now we calculate the probability that a given allele in that ancestor has been passed on to both of you. Each step is a meiotic division with 1⁄2 (0.5) probability that the grandparents' allele is passed to your parent and then to you. There are four such steps in each path. Since you have two common ancestors, we will use the probability rule (adding the individual probabilities of sharing an allele from your grandmother and of sharing an allele from your grandfather). The chance you share an allele through one specific grandparent is 0.54 = 0.0625, but the total probability that you share an allele from either grandparent is r = 0.54 + 0.54 = 0.125.

Calculate the coefficient of relatedness (r) between you and your first cousin. Select one: a. r = 0.625 b. r = 0.225 c. r = 0.125 d. r = 0.062

d. reciprocal altruism

Conflict is also widely studied in the evolution of sociality. Conflict manifests itself in many ways in nature. Which of the following is NOT a manifestation of conflict that evolutionary biologists study? Select one: a. aggressive behavior between nonrelated individuals b. conflict within families and related groups, such as parent- offspring conflict c. conflict within genomes, such as segregation distorter alleles d. reciprocal altruism

families

Conflict is very important in studies of evolution of social behavior. Besides the obvious aggression and other types of conflict between nonrelated (nonkin) individuals and groups, conflict is also manifested in ____. In addition, there are conflict studies at the intragenomic level. It is important to analyze the conditions (such as costs and benefits of natural selection) that would favor conflict over cooperation.

phenotype; cultural evolution

Cultural transmission is often defined as the transfer of information from individual to individual through social learning or teaching. A slightly different way of saying this is that cultural transmission is a system of information transfer that affects an individual's _____ via social learning (Bonner 1980; Cavalli-Sforza and Feldman 1981; Boyd and Richerson 1985). Although cultural and genetic transmission each provide a means of passing traits down from one generation to another, when social learning occurs, information can be spread through a population very quickly. Cultural transmission can change the frequency of behavioral traits, not only across generations, but also within a single generation. When this leads to changes in the frequency of traits within or between generations, we could use the expression ______.

cospeciation

Dale Clayton and his team found that the larger lice species tended to live on larger species of pigeons and doves. The researchers hypothesized that there were benefits to lice if they stayed on size-matched species. They tested this hypothesis in their experiment, confirming that small lice benefited from small host species, while large lice benefited from large host species. When speciation occurred in birds, their lice were constrained to remain on their hosts because of the benefits of size matching, as well as risks of switching to another host where they could be picked by the host more efficiently. This tight linkage between host and parasite is expected to lead to _____ events, such as those observed in the lice-pigeon phylogeny.

d. The vast majority of variation in humans occurs within, not between, populations. Human groups are not genetically distinct. FEEDBACK: To the surprise of many, human population groups are not genetically distinct despite fairly obvious differences in features. Additionally, there are very few alleles that are uniquely diagnostic of a particular geographic region. Recent statistical evidence indicates that within- population variation comprises 93% to 95% of total human variation. Read the beginning of Section 19.5 titled "Migration of Modern Humans."

Different characteristic features of modern humans, such as skin color and hair form, offer substantial clues to ancestral origin (for example, African versus Asian). What do we know about genetic variability between the many distinct geographic populations of modern humans? Select one: a. Human variation is lower between populations that reside on the same continent, but increases with intercontinental distance. b. There is very little genetic variation on a regional level, but substantial variation with increasing geographic distance. c. Genetic studies have failed to resolve most population- level differences despite the obvious morphological differences seen between races. d. The vast majority of variation in humans occurs within, not between, populations. Human groups are not genetically distinct.

d. In paper wasps, increased "brokenness" of the black patterning on the face is a conventional signal associated with poor fighting ability.

Elizabeth Tibbetts has demonstrated that paper wasps (Polistes dominulus) use a type of conventional signal to communicate their fighting abilities. Which of the following is FALSE about the social communication of these wasps? Select one: a. Paper wasps recognize when signals are not honest and react accordingly, attacking those individuals with facial markings that falsely indicate dominance and high fighting ability. b. The majority of the signals in paper wasps are kept honest by social punishment. c. Signalers pay no cost unless they overstate their quality. d. In paper wasps, increased "brokenness" of the black patterning on the face is a conventional signal associated with poor fighting ability.

c. 50%; 50%

For any given allele copy in a diploid parent, there is a __________ chance that this allele will be passed on to each offspring and a __________ chance that the homologous allele will be passed on instead. Select one: a. 60%; 40% b. 70%; 30% c. 50%; 50% d. 40%; 60%

cultural transmission; culturally

Grants' study- If song types were genetically controlled, we would expect the songs of the sons to be similar to the songs of both their paternal and maternal grandfathers. If _____ from father to son is the mechanism, then the songs of the sons should resemble those of their paternal grandfather, not those of their maternal grandfather. Such a ____ transmitted trait provides females with a means to recognize individuals of their own species, which in turn reduces hybridization between the two species.