
Reading Passage Question
Anthropologists once thought that the ancestors of modern humans began to walk upright because it freed their hands to use stone tools, which they had begun to make as the species evolved a brain of (5) increased size and mental capacity. But discoveries of the three-million-year-old fossilized remains of our hominid ancestor Australopithecus have yielded substantial anatomical evidence that upright walking appeared prior to the dramatic enlargement of the (10) brain and the development of stone tools.
Walking on two legs in an upright posture (bipedal locomotion) is a less efficient proposition than walking on all fours (quadrupedal locomotion) because several muscle groups that the quadruped uses for propulsion (15) must instead provide the biped with stability and control. The shape and configuration of various bones must likewise be modified to allow the muscles to perform these functions in upright walking. Reconstruction of the pelvis (hip bones) and (20) femur (thighbone) of “Lucy”, a three-million-year-old skeleton that is the most complete fossilized skeleton from the australopithecine era, has shown that they are much more like the corresponding bones of the modern human than like those of the most closely (25) related living primate, the quadrupedal chimpanzee. Lucy’s wide, shallow pelvis is actually better suited to bipedal walking than is the rounder, bowl-like pelvis of the modern human, which evolved to form the larger birth canal needed to accommodate the head of a (30) large-brained human infant. By contrast, the head of Lucy’s baby could have been no larger than that of a baby chimpanzee.
If the small-brained australopithecines were not toolmakers, what evolutionary advantage did they (35) gain by walking upright? One theory is that bipedality evolved in conjunction with the nuclear family: monogamous parents cooperating to care for their offspring. Walking upright permitted the father to use his hands to gather food and carry it to his mate (40) from a distance, allowing the mother to devote more time and energy to nurturing and protecting their children. According to this view, the transition to bipedal walking may have occurred as long as ten million years ago, at the time of the earliest hominids, (45) making it a crucial initiating event in human evolution.
“Anthropologists once thought that the ancestors of modern humans began to walk upright because it freed their hands to use stone tools''- is a GMAT reading comprehension passage with answers. Candidates need a strong knowledge of English GMAT reading comprehension.
This GMAT Reading Comprehension consists of 5 comprehension questions. The GMAT Reading Comprehension questions are designed for the purpose of testing candidates’ abilities in understanding, analyzing, and applying information or concepts. Candidates can actively prepare with the help of GMAT Reading Comprehension Practice Questions.
Solution and Explanation
Answer: A
Explanation: According to the passage, it was formerly a common belief that the ancestors of
contemporary humans started walking upright and using stone tools at around the same period.
The sentence implies that upright walking provided some form of evolutionary benefit since it allowed monogamous parents to collaborate in the care of children. Despite the fact that walking upright is less efficient than going on all fours.
Answer: C
Explanation: Because one event followed another closely, it is possible to simultaneously rule out all of the other possibilities. The expansion of the brain occurred quite sometime after the emergence of bipedal mobility; thus, it is the most recent phase in the evolution of the human brain.
Answer: D
Explanation: One of the most common forms of locomotion is bipedalism, which involves moving about on two feet. Primates are capable of walking on two legs to varying degrees. All primates sit erect. Many can stand erect without leaning on their arms to support their body weight, and some, particularly the apes, can even walk upright for brief periods. It is a fallacious viewpoint to assume that uprightness is a characteristic unique to humans. Simply put, humans are the only species of this order to realize the potential offered by this lineage fully.
Answer: B
Explanation: The passage mentions that the australopithecine pelvis was more adapted for bipedal walking than the current human pelvis, as was already mentioned. This shows that contemporary humans are less suited to walking erect than australopithecines were. Because of how Lucy's pelvis was shaped, we know that hominids were better adapted to walking upright than humans.
Answer: E
Explanation: It was more accessible for the female to dedicate more time since the male could obtain food and transport it over a greater distance than she could. Therefore, until she could walk upright, she would have had very little time to tend to and defend her young since both parents were required to seek food for themselves.
Suggested GMAT Reading Comprehension Samples
*The article might have information for the previous academic years, please refer the official website of the exam.