5) Which of the following statements would be most acceptable to most zoologists?

1. A) The first fossils resembling lancelets appeared in the fossil record around 10 million years ago.
2. B) Recent work in molecular systematics supports the hypothesis that lancelets are the basal clade of chordates.
3. C) The extant lancelets are the immediate ancestors of the fishes.
4. D) Lancelets do not swim in the same way that fishes do.

b

6) Which extant chordates are postulated to be most like the earliest chordates in appearance?

1. A) lancelets
2. B) adult tunicates
3. C) amphibians
4. D) chondrichthyans

a

7) Vertebrates and tunicates share ________.

1. A) jaws adapted for feeding
2. B) a high degree of cephalization
3. C) the formation of structures from the neural crest
4. D) a notochord and a dorsal, hollow nerve cord

d

8) All chordates studied to date, except tunicates, share a set of ________.

1. A) 13 Hox genes
2. B) 5 Dlx genes
3. C) 9 Otx genes
4. D) 7 FOXP2 genes

a

9) Which of the following characteristics is shared by a hagfish and a lamprey?

1. A) a rasping tongue
2. B) paired fins
3. C) jaws
4. D) a well-developed notochord

d

10) A new species of aquatic chordate is discovered that closely resembles an ancient form. It has the following characteristics: external armor of bony plates, no paired lateral fins, and a suspension-feeding mode of nutrition. In addition to these, it will probably have which of the following characteristics?

1. A) legs
2. B) no jaws
3. C) an amniotic egg
4. D) endothermy

b

11) The earliest known mineralized structures in vertebrates are associated with ________.

1. A) feeding
2. B) locomotion
3. C) defense
4. D) respiration

a

12) A team of researchers has developed a poison that has proven effective against lamprey larvae in freshwater cultures. The poison is ingested and causes paralysis by detaching segmental muscles from the skeletal structures. The team wants to test the poison's effectiveness in streams flowing into Lake Michigan, but one critic worries about potential effects on lancelets, which are similar to lampreys in many ways. Why is this concern misplaced?

1. A) Lamprey larvae and lancelets have very different feeding mechanisms.
2. B) Lancelets do not have segmental muscles.
3. C) Lancelets live only in saltwater environments.
4. D) Lancelets and lamprey larvae eat different kinds of food.

c

13) To reproduce, many plants produce seeds—structures containing embryonic offspring along with nutrients inside a tough coat. These offspring develop after being released by the parent plant. To which animal reproductive "strategy" is seed production most comparable?

1. A) oviparous reproduction
2. B) ovoviviparous reproduction
3. C) viviparous reproduction
4. D) internal development and ballistic dispersal

a

14) Why do skates and rays have flattened bodies, while sharks are torpedo shaped?

1. A) Sharks are more closely related to the tube-like lampreys than are skates and rays.
2. B) Skates and rays need enlarged pectoral fins to help them stay level in turbulent water, while sharks do not.
3. C) Skates and rays exchange gases across their skin and thus require a high surface-area-to-volume ratio, while sharks use gills to respire.
4. D) Sharks are streamlined for active swimming at mid-depths, while skates move about mostly on the ocean bed.

d

15) Which of these statements accurately describes a similarity between sharks and ray-finned fishes?

1. A) They are equally able to exchange gases with the environment while stationary.
2. B) They are highly maneuverable due to their flexibility.
3. C) They have a lateral line that is sensitive to vibrations.
4. D) A swim bladder helps control buoyancy.

c

The presence of a swim bladder allows the typical ray-finned fish to stop swimming and still ________.

1. A) effectively circulate its blood
2. B) use its lateral line system
3. C) use its swim bladder as a respiratory organ
4. D) not sink

d

Which shark structure is closest in function to a swim bladder full of gas?

1. A) its lateral line system
2. B) its spiral valve
3. C) its liver
4. D) its gills

c

If a ray-finned fish is to both hover (remain stationary) in the water column and ventilate its gills effectively, then what other structure besides its swim bladder will it use?

1. A) its pectoral fins
2. B) its lateral line system
3. C) its caudal (tail) fin
4. D) its operculum

d

19) How did the evolution of the jaw contribute to diversification of early vertebrate lineages?

1. A) It allowed for smaller body size.
2. B) It was the first stage in the development of a bony skull.
3. C) It made additional food sources available.
4. D) It increased the surface area for respiration and feeding.

c

20) It is believed that the coelacanths and lungfish represent a crucial link between other fishes and tetrapods. What is the major feature in these fish in support of this hypothesis?

1. A) Like amphibians, they are tied to the water for reproduction.
2. B) Their fins have skeletal and muscular structures similar to amphibian limbs.
3. C) They have highly evolved nervous and circulatory systems.
4. D) They have lungs and are able to breathe air when water is scarce.

b

21) Jaws first occurred in which extant group of fishes?

1. A) lampreys
2. B) chondrichthyans
3. C) ray-finned fishes
4. D) placoderms

d

22) Which of these might have been observed in the common ancestor of chondrichthyans and osteichthyans?

1. A) a mineralized, bony skeleton
2. B) opercula
3. C) a spiral valve intestine
4. D) a swim bladder

a

23) Arrange these groups in order from most inclusive (most general) to least inclusive (most specific).

1. A) osteichthyans, gnathostomes, lobe-fins, tetrapods, amphibians
2. B) osteichthyans, gnathostomes, amphibians, tetrapods, lobe-fins
3. C) gnathostomes, osteichthyans, lobe-fins, tetrapods, amphibians
4. D) gnathostomes, osteichthyans, tetrapods, lobe-fins, amphibians

c

24) At one time, Chondrichthyes were thought to have split off from other vertebrates before the evolution of bone. Now we have concluded that the Chondrichthyes split off after the evolution of bone had started. This change demonstrates ________.

1. A) characteristics can be lost in evolution
2. B) evolution is one-way and straight line
3. C) hagfishes and lampreys have ancestors with bone
4. D) cartilage contributes to keeping sharks light so they do not sink

a

25) At one time, Chondrichthyes were thought to have split off from other vertebrates before the evolution of bone. Now we have concluded that the Chondrichthyes split off after the evolution of bone had started. This change demonstrates ________.

1. A) as new evidence emerges, scientists revise their hypotheses
2. B) scientists develop hypotheses and only accept data that confirm their hypotheses
3. C) revisions of hypotheses take many years
4. D) scientists accept the simplest hypotheses

a

26) Guppies are a common aquarium fish. They have internal fertilization, and females give birth to young that can swim immediately. Which of the following statements is correct?

1. A) Most fish reproduce like guppies.
2. B) Guppies reproduce by producing swimming young because they are related to marsupials.
3. C) Most fish reproduce by laying eggs.
4. D) Most fish produce amniote eggs.

c

27) Scientific views are based on evidence rather than an appeal to authority. Which of the following statements demonstrates a conclusion based on evidence?

1. A) We conclude that lungs evolved before swim bladders because a study of branching patterns shows that some of the oldest lineages of Osteichthyes have lungs.
2. B) We conclude that lungs evolved before swim bladders because Darwin wrote that swim bladders evolved before lungs in The Origin of Species.
3. C) We conclude that lungs evolved before swim bladders because the oldest osteichthyan fossils show lungs arising before swim bladders.
4. D) We conclude that lungs evolved before swim bladders because Hox genes direct the evolution of swim bladders but not of lungs.

a

28) Scientific views are based on evidence rather than an appeal to authority. Which of the following statements demonstrates a conclusion based on an appeal to authority?

1. A) We conclude that lungs evolved before swim bladders because a study of branching patterns show that some of the oldest lineages of Osteichthyes have lungs.
2. B) We conclude that lungs evolved before swim bladders because Darwin wrote that swim bladders evolved before lungs in The Origin of Species.
3. C) We conclude that lungs evolved before swim bladders because the oldest osteichthyan fossils show lungs arising before swim bladders.
4. D) We conclude that lungs evolved before swim bladders because Hox genes direct the evolution of swim bladders but not of lungs.

b

29) Which of the following characteristics allowed early gnathostomes to become successful predators?

1. A) fins stiffened with bone that increased maneuverability and improved gas exchange through the skin
2. B) fins stiffened with bone that increased maneuverability and improved gas exchange in the gills
3. C) lobe fins that allowed temporary access to land and improved gas exchange through the skin
4. D) lobe fins that allowed temporary access to land and improved gas exchange in the gills

b

30) Suppose, while out camping in a forest, you found a chordate with a long, slender, limbless body slithering across the ground near your tent. This critter could be ________.

1. A) a lamprey
2. B) a mammal
3. C) an amphibian
4. D) a skate

c

31) Use the following information to answer the question.

While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-meter-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).

The class decided to humanely euthanize the organism and subsequently dissect it. Having decided that it was probably not a reptile, two of their original hypotheses regarding its identity remained. Which of the following, if observed, should help them arrive at a conclusive answer?

1. A) presence of moist, highly vascularized skin
2. B) presence of lungs
3. C) presence of a nerve cord
4. D) presence of a digestive system with two openings

b

32) Use the following information to answer the question.

While on an intersession course in tropical ecology, Kris pulls a large, snakelike organism from a burrow (the class was granted a collecting permit). The 1-meter-long organism has smooth skin, which appears to be segmented. It has two tiny eyes that are hard to see because they seem to be covered by skin. Kris brings it back to the lab at the field station, where it is a source of puzzlement to the class. Kris says that it is a giant oligochaete worm; Shaun suggests it is a legless amphibian; Kelly proposes it belongs to a snake species that is purely fossorial (lives in a burrow).

The organism was found to have two lungs, but the left lung was much smaller than the right lung. Kelly added that the herpetology instructor had said that in most snakes, the same condition exists. If the size difference between the lungs in this organism is not a shared ancestral characteristic with its occurrence in snakes, then its existence in this organism is explained as which of the following?

1. A) a result of convergent evolution
2. B) a result of convergent evolution and a similar adaptation to a shared lifestyle or body plan
3. C) an example of homologous structures and a similar adaptation to a shared lifestyle or body plan
4. D) a similar adaptation to a shared lifestyle or body plan and a result of having identical Hox genes

b

33) Which of the following could be considered the most recent common ancestor of living tetrapods?

1. A) a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates
2. B) an armored, jawed placoderm with two pairs of appendages
3. C) an early ray-finned fish that developed bony skeletal supports in its paired fins
4. D) a salamander that had legs supported by a bony skeleton but moved with the side-to-side bending typical of fishes

a

34) A trend first observed in the evolution of the earliest tetrapods was ________.

1. A) the appearance of jaws
2. B) feet with digits
3. C) the mineralization of the endoskeleton

D) the amniotic egg

b

35) Ancient fossils that seem to be an intermediate stage in the evolution from fish to tetrapods had which of the following characteristics?

1. A) fins and scales like a fish but ribs to support the body and a bone structure in the front limb like tetrapods
2. B) a pelvis and rear limbs like a fish and gills like a tetrapod
3. C) bones that allowed the head to move like a fish and both gills and lung like a tetrapod
4. D) scales and a tail like a fish and a simple bone arrangement in the back limb like a tetrapod

a

36) Fossils of the earliest tetrapods should ________.

1. A) show evidence of internal fertilization
2. B) show evidence of having produced shelled eggs
3. C) indicate limited adaptation to life on land
4. D) feature the earliest indications of the appearance of jaws

c

37) Use the following information to answer the question.

Terry catches a ray-finned fish from the ocean and notices that attached to its flank is an equally long, snakelike organism. The attached organism has no external segmentation, no scales, a round mouth surrounded by a sucker, and two small eyes. Terry concludes it is a hagfish.

Terry saved some of the tooth-like objects within the hagfish's round mouth to analyze their composition in his mentor's biochemistry research lab. Terry will find that they are composed of the same protein found in tetrapod ________.

1. A) scales
2. B) teeth
3. C) bones
4. D) cartilage

a

38) What is believed to be the most significant result of the evolution of the amniotic egg?

1. A) Tetrapods are no longer tied to the water for reproduction.
2. B) Tetrapods can now function with just lungs.
3. C) Newborns are much less dependent on their parents.
4. D) Embryos are protected from predators.

a

39) Which structure of the amniotic egg most closely surrounds the embryo?

1. A) the chorion
2. B) the yolk sac
3. C) the allantois
4. D) the amnion

d

40) The evolution of similar insulating skin coverings such as fur, hair, and feathers in mammals and birds is a result of ________.

1. A) shared ancestry
2. B) convergent evolution
3. C) homology
4. D) evolutionary divergence

b

41) Which of the following characteristics evolved independently in mammals and birds?

1. A) amniotic eggs
2. B) jaws
3. C) bone
4. D) endothermy

d

42) Suppose you traveled back in time and located the first animals to have evolved feathers. You found that these animals were tree-dwelling ectotherms, able to run quickly but unable to fly. You also noticed that only males had feathers. Which hypothesis of feather evolution would these data most support? Feathers initially evolved in a role associated with ________.

1. A) flight
2. B) insulation
3. C) courtship behavior
4. D) gliding

c

43) Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit?

1. A) endothermy
2. B) ectothermy
3. C) amniotic egg
4. D) terrestrial habitat

a

44) Which characteristic is common to all the modern representatives of all major reptilian lineages (turtles, lepidosaurs, crocodilians, and birds)?

1. A) presence of teeth
2. B) presence of four walking limbs
3. C) ectothermy
4. D) presence of a notochord

d

45) Which of these are amniotes?

1. A) amphibians
2. B) fishes
3. C) turtles
4. D) lungfish

c

46) Use the following information to answer the question.

Due to its system of air sacs connected to the lungs, the respiratory system of birds is arguably the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi.

If the inner lining of the air sacs is neither thin nor highly vascularized, then what can be inferred about the air sacs?

1. A) They must not belong to the respiratory system.
2. B) They cannot be derived from endoderm.
3. C) They are not efficient sites of gas exchange between air and blood.
4. D) They cannot effectively moisturize the air before it reaches the lungs.

c

47) Use the following information to answer the question.

Due to its system of air sacs connected to the lungs, the respiratory system of birds is arguably the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air sacs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi.

The one-way flow of air along parabronchi makes what type of gas exchange mechanism possible, at least theoretically?

1. A) the same as that occurring in fish gills
2. B) the same as that occurring in insect tracheae
3. C) the same as that occurring in mammalian lungs
4. D) the same as that occurring in echinoderm skin gills

a

48) Which of these characteristics contributed the most to vertebrate success in relatively dry environments?

1. A) the shelled, amniotic egg
2. B) the ability to maintain a constant body temperature
3. C) two pairs of appendages
4. D) a four-chambered heart

a

49) Which of the following are the only extant animals that descended directly from dinosaurs?

1. A) lizards
2. B) crocodiles
3. C) birds
4. D) tuataras

c

50) During chordate evolution, what is the sequence (from earliest to most recent) in which the following structures arose?

1. A) paired fins, jaws, swim bladder, amniotic egg, four-chambered heart
2. B) jaws, paired fins, swim bladder, four-chambered heart, amniotic egg
3. C) jaws, paired fins, paired fins, swim bladder, four-chambered heart
4. D) paired fins, amniotic egg, four-chambered heart, jaws, swim bladder

a

51) Which clade does not include humans?

1. A) lobe-fins
2. B) diapsids
3. C) amniotes
4. D) osteichthyans

b

52) At one time, birds held the same taxonomic rank as Reptilia and Mammalia. Now, however, they are considered as part of the reptile clade. Without this change, ________.

1. A) birds would be considered Mammalia because both groups are endothermic
2. B) birds would be classified according to traits that were convergently evolved
3. C) Reptilia would be paraphyletic
4. D) Reptilia would be monophyletic

c

53) Birds are descended from species that laid eggs in water. It could be argued that embryos of birds still develop in water because ________.

1. A) the shell keeps the embryo from drying out
2. B) the amnion encases each embryo in water
3. C) the chorion, allantois, and yolk sac provide embryos with nutrients and waste disposal
4. D) the amnion protect the embryo in the same way that a seed coat protects plant embryos of flowering plants

b

54) Which of the following types of evidence would be useful in understanding if the impact of a comet caused the extinction of the dinosaurs?

1. A) more DNA analyses
2. B) more comparison of skeletal structures
3. C) more phylogenetic studies
4. D) more detailed collection of fossils

d

55) Primate evolution and behavior, such as hunting skills, have been directed in part by the development of depth perception. What anatomical change made depth perception possible?

1. A) a larger brain
2. B) the formation of compound eyes
3. C) location of the eyes at the front of the head
4. D) diurnal activity

c

56) What group of mammals have (a) embryos that spend more time feeding through the placenta than the mother's nipples, (b) young that feed on milk, and (c) a prolonged period of maternal care after leaving the placenta?

1. A) Eutheria
2. B) Marsupiala
3. C) Monotremata
4. D) Lagomorpha

a

57) Which of the following represents the strongest evidence that two of the three middle ear bones of mammals are homologous to certain reptilian jawbones?

1. A) They are similar in size to the reptilian jawbones.
2. B) They are similar in shape to the reptilian jawbones.
3. C) The mammalian jaw has fewer bones than does the reptilian jaw.
4. D) These bones can be observed to move from the developing jaw to the developing middle ear in mammalian embryos.

d

58) Which of the following is the most inclusive (most general) group in which all of the members have fully opposable thumbs?

1. A) apes
2. B) Homo
3. C) anthropoids
4. D) primates

c

59) Which of these would a paleontologist most likely do to determine if a fossil represents a reptile or a mammal?

1. A) Look for the presence of milk-producing glands.
2. B) Look for the mammalian characteristics of a four-chambered heart and a diaphragm.
3. C) Use molecular analysis to look for the protein keratin.
4. D) Examine the teeth.

d

60) Female birds lay their eggs, thereby facilitating flight by reducing weight. Which "strategy" seems most likely for female bats to use to achieve the same goal?

1. A) limit litters to a single embryo
2. B) refrain from flying throughout pregnancy (about six weeks long)
3. C) give birth to underdeveloped young, and subsequently carry them in a pouch that has teats
4. D) feed multiple embryos internally using placentas

a

61) Unlike eutherians, both monotremes and marsupials ________.

1. A) lack nipples
2. B) have some embryonic development outside the uterus
3. C) lay eggs
4. D) are found in Australia and Africa

b

62) Which of the following statements about the geographic distribution of marsupials is accurate?

1. A) they occur only in Australia and New Guinea
2. B) they occur on all continents except Antarctica
3. C) they occur in Australia and the Americas
4. D) they occur only in Africa

c

63) Marsupials survived in Australia (as opposed to Asia) because ________.

1. A) marsupials were better adapted to the climatic conditions of Australia than were eutherians
2. B) marsupials were, and are, better competitors than eutherians
3. C) Australia had separated from Pangea, and eutherians were not able to invade Australia
4. D) continental drift, caused by plate tectonic processes, allowed eutherians to invade Asia and the Americas

c

64) On the back of your skull you can feel a small bump, below which is an opening where the spinal cord enters the skull. The location of this opening toward the bottom of the skull is significant in evolutionary biology for what reason?

1. A) It allowed for the hominin brain to grow much larger than other primates.
2. B) It provided greater protection for the spinal cord.
3. C) It occurred as a result of the change to a bipedal stance.
4. D) This change was necessary for the increase in size from prosimian forms to anthropoid forms.

c

65) Use the following information to answer the question.

Brown et al. and Morwood et al. reported in 2004 that they had found skeletal remains of a previously unknown type of hominin, now dubbed Homo floresiensis, on the Indonesian island of Flores. These hominins were small (approximately 1 meter tall) with small braincases (approximately 380 cubic centimeters) as compared with other hominins. The remains of H. floresiensis were found alongside handmade stone tools and the remains of dwarf elephants that also inhabited the island, suggesting that H. floresiensis was able both to make tools and to coordinate the hunting of animals much larger than itself. H. floresiensis is estimated to have lived at the site where the remains were found from at least 38,000 years ago to 18,000 years ago.

Which would be the most feasible method of figuring out to which other hominin species H. floresiensis was most closely related?

1. A) Compare the type of prey hunted by floresiensis to that hunted by each of the other hominin species.
2. B) Compare the average body size of floresiensis to that of each of the other hominin species.
3. C) Compare the skeletal morphology of floresiensis to that of each of the other hominin species.
4. D) Compare the estimated life span of floresiensis to that of each of the other hominin species.

c

66) In what respect do hominins differ from all other anthropoids?

1. A) lack of a tail
2. B) eyes on the front of the face
3. C) bipedal posture
4. D) opposable thumbs

c

68) Use the following information to answer the question.

Brown et al. and Morwood et al. reported in 2004 that they had found skeletal remains of a previously unknown type of hominin, now dubbed Homo floresiensis, on the Indonesian island of Flores. These hominins were small (approximately 1 meter tall) with small braincases (approximately 380 cubic centimeters) as compared with other hominins. The remains of H. floresiensis were found alongside handmade stone tools and the remains of dwarf elephants that also inhabited the island, suggesting that H. floresiensis was able both to make tools and to coordinate the hunting of animals much larger than itself. H. floresiensis is estimated to have lived at the site where the remains were found from at least 38,000 years ago to 18,000 years ago.

It is speculated that H. floresiensis and H. sapiens may have lived on Flores concurrently. Suppose researchers obtained mitochondrial DNA samples from the H. floresiensis remains, amplified a 1,000-base-pair sequence via PCR, and compared it to that of several currently living H. sapiens native to Indonesia, North Africa, and North America. Also suppose H. floresiensis were found to differ from the average Indonesian H. sapiens in 28 base pairs, from the average North African H. sapiens in 51 base pairs, and from the average North American H. sapiens in 53 base pairs, while two randomly selected H. sapiens differed from each other in an average of 21 base pairs. What would you surmise from these data?

1. A) floresiensis and H. sapiens probably did not live on Flores concurrently.
2. B) floresiensis and H. sapiens probably lived on Flores concurrently but did not interact.
3. C) floresiensis and H. sapiens probably lived on Flores concurrently, and H. sapiens killed and consumed H. floresiensis.
4. D) floresiensis and H. sapiens probably lived on Flores concurrently and interbred to some degree.

d

69) Arrange the following taxonomic terms in order from most inclusive (most general) to least inclusive (most specific).

1. A) primates, apes, anthropoids, hominins, Homo
2. B) primates, anthropoids, apes, hominins, Homo
3. C) primates, anthropoids, hominins, Homo
4. D) primates, hominins, apes, anthropoids, Homo

b

70) Which of these traits is most strongly associated with the adoption of bipedalism?

1. A) enhanced depth perception
2. B) shortened hind limbs
3. C) opposable big toe
4. D) repositioning of foramen magnum

d

71) Which of the following statements about human evolution is correct?

1. A) Modern humans are the only human species to have evolved on Earth.
2. B) Human ancestors were virtually identical to extant chimpanzees.
3. C) Human evolution has occurred within an unbranched lineage.

D) The upright posture and enlarged brain of humans evolved separately

d

72) With which of the following statements would a biologist be most inclined to agree?

1. A) Humans and other apes represent divergent lines of evolution from a common ancestor.
2. B) Humans represent the pinnacle of evolution and have escaped from being affected by natural selection.
3. C) Humans evolved from chimpanzees.
4. D) Humans and other apes are the result of disruptive selection in a species of chimpanzee.

a

73) Which of the following taxonomic groups is the most successful?

1. A) Fungi are the most successful, based on their ability to digest cellulose, the most common organic compound on Earth.
2. B) Bony fishes are the most successful, based on their high species diversity (almost as many as all other vertebrates combined).
3. C) Mammals are the most successful, based on their complex mode of reproduction.
4. D) All extant species are successful, based on their continuing existence.

d

74) Which of the following characteristics occur in Homo naledi?

1. A) large brain, feet that allowed bipedal walking, hands able to manipulate small objects
2. B) large brain, feet that allowed occasional erect posture, hands able to manipulate small objects
3. C) small brain, feet that allowed bipedal walking, hands able to manipulate small objects
4. D) small brain, feet that allowed bipedal walking, hands able to swing from branch to branch

c

75) The history of hominin evolution demonstrates ________.

1. A) unrelated traits (that is, characters of skulls and hips/feet) evolve together
2. B) unrelated traits can evolve at different rates
3. C) the decrease in rainfall favored maintaining the ability to climb trees
4. D) the increase in rainfall favored the ability to walk upright

b

76) Many sentences in this chapter include the words "may suggest." This phrase indicates that ________.

1. A) causality of a pattern is uncertain
2. B) there is no cause-and-effect association
3. C) the author is explaining a well-established relationship
4. D) scientists agree on the cause of a pattern

a