Micro-wear patterns found on the teeth of long-extinct specimens of the primate species australopithecine may provide evidence about their diets. For example, on the basis of tooth micro-wear patterns, Walker dismisses Jolly’s hypothesis that australopithecines ate hard seeds. He also disputes Szalay’s suggestion that the heavy enamel of australopithecine teeth is an adaptation to bone crunching, since both seed cracking and bone crunching produce distinctive micro-wear characteristics on teeth. His conclusion that australopithecines were frugivores (fruit eaters) is based upon his observation that the tooth micro-wear characteristics of east African australopithecine specimens are indistinguishable from those of chimpanzees and orangutans, which are commonly assumed to be frugivorous primates.
However, research on the diets of contemporary primates suggests that micro-wear studies may have limited utility in determining the foods that are actually eaten. For example, insect eating, which can cause distinct micro-wear patterns, would not cause much tooth abrasion in modern baboons, who eat only soft-bodied insects rather than hard-bodied insects. In addition, the diets of current omnivorous primates vary considerably depending on the environments that different groups within a primate species inhabit; if australopithecines were omnivores too, we might expect to find considerable population variation in their tooth micro-wear patterns. Thus, Walker’s description of possible australopithecine diets may need to be expanded to include a much more diverse diet.
1. According to the passage, Walker and Szalay disagree on which of the following points?(A) The structure and composition of australopithecine teeth
(B) The kinds of conclusions that can be drawn from the micro-wear patterns on australopithecine teeth
(C) The idea that fruit was a part of the australopithecine diet
(D) The extent to which seed cracking and bone crunching produce similar micro-wear patterns on teeth
(E) The function of the heavy enamel on australopithecine teeth
2. The passage suggests that Walker’s research indicated which of the following about australopithecine teeth?(A) They had micro-wear characteristics indicating that fruit constituted only a small part of their diet.
(B) They lacked micro-wear characteristics associated with seed eating and bone crunching.
(C) They had micro-wear characteristics that differed in certain ways from the micro-wear patterns of chimpanzees and orangutans.
(D) They had micro-wear characteristics suggesting that the diet of australopithecines varied from one region to another.
(E) They lacked the micro-wear characteristics distinctive of modern frugivores.
3. The passage suggests that which of the following would be true of studies of tooth micro-wear patterns conducted on modern baboons?(A) They would inaccurately suggest that some baboons eat more soft-bodied than hard-bodied insects.
(B) They would suggest that insects constitute the largest part of some baboons’ diets.
(C) They would reveal that there are no significant differences in tooth micro-wear patterns among baboon populations.
(D) They would inadequately reflect the extent to which some baboons consume certain types of insects.
(E) They would indicate that baboons in certain regions eat only soft-bodied insects, whereas baboons in other regions eat hard-bodied insects.
4. The passage suggests which of the following about the micro-wear patterns found on the teeth of omnivorous primates?(A) The patterns provide information about what kinds of foods are not eaten by the particular species of primate, but not about the foods actually eaten.
(B) The patterns of various primate species living in the same environment resemble one another.
(C) The patterns may not provide information about the extent to which a particular species’ diet includes seeds.
(D) The patterns provide more information about these primates’ diet than do the tooth micro-wear patterns of primates who are frugivores.
(E) The patterns may differ among groups within a species depending on the environment within which a particular group lives.
5. It can be inferred from the passage that if studies of tooth micro-wear patterns were conducted on modern baboons, which of the following would most likely be true of the results obtained?(A) There would be enough abrasion to allow a determination of whether baboons are frugivorous or insectivorous.
(B) The results would suggest that insects constitute the largest part of the baboons’ diet.
(C) The results would reveal that there are no significant differences in tooth micro-wear patterns from one regional baboon population to another.
(D) The results would provide an accurate indication of the absence of some kinds of insects from the baboons’ diet.
(E) The results would be unlikely to provide any indication of what inferences about the australopithecine diet can or cannot be drawn from micro-wear studies.
6. It can be inferred from the passage that Walker’s conclusion about the australopithecine diet would be called into question under which of the following circumstances?(A) The tooth enamel of australopithecines is found to be much heavier than that of modern frugivorous primates.
(B) The micro-wear patterns of australopithecine teeth from regions other than east Africa are analyzed.
(C) Orangutans are found to have a much broader diet than is currently recognized.
(D) The environment of east Africa at the time australopithecines lived there is found to have been far more varied than is currently thought.
(E) The area in which the australopithecine specimens were found is discovered to have been very rich in soft-bodied insects during the period when australopithecines lived there.
7. The author of the passage mentions the diets of baboons and other living primates most likely in order to(A) provide evidence that refutes Walker’s conclusions about the foods making up the diets of australopithecines
(B) suggest that studies of tooth micro-wear patterns are primarily useful for determining the diets of living primates
(C) suggest that australopithecines were probably omnivores rather than frugivores
(D) illustrate some of the limitations of using tooth micro-wear patterns to draw definitive conclusions about a group’s diet
(E) suggest that tooth micro-wear patterns are caused by persistent, as opposed to occasional, consumption of particular foods
8. The passage is primarily concerned with(A) comparing two research methods for determining a species' dietary habits
(B) describing and evaluating conjectures about a species' diet
(C) contrasting several explanations for a species' dietary habits
(D) discussing a new approach and advocating its use in particular situations
(E) arguing that a particular research methodology does not contribute useful data