题目信息
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
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
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
must instead be adapted to 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 (hipbones) and
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
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
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
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
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,
making it a crucial initiating event in human evolution.
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
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
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
must instead be adapted to 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 (hipbones) and
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
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
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
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
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,
making it a crucial initiating event in human evolution.
The primary purpose of the passage is to
A:present an interpretation of the chronological relationship between bipedal locomotion and certain other key aspects of human evolution
B:compare the evolutionary advantages and disadvantages of bipedal locomotion to those of quadrupedal locomotion
C:argue that the transition to a nuclear family structure was a more crucial step in human evolution than was the development of stone tools
D:analyze anatomical evidence of bipedal locomotion to show that the large brain of modern humans developed at a later stage of evolution than was previously believed
E:use examples of muscle and bone structure to illustrate the evolutionary differences between modern humans, australopithecines, and chimpanzees
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已选答案：
正确答案：
A:present an interpretation of the chronological relationship between bipedal locomotion and certain other key aspects of human evolution
第一段提出问题。
曾认为，古人类大脑发展的同时学习使用工具，后来则开始直立行走。但考古发现表明先直立行走，继而大脑发展、运用工具。
第二段展开说明古人类双足行走的骨骼特点。
两足移动低效，因为肌肉用以进行平衡而非提供推进力了。骨骼也需相应调整。Lucy的髋骨和大腿骨更近于现代人类。Lucy的髋骨较人类宽扁，更适合双足行走，人类的髋骨则为生育大头后代的需要而变圆了。Lucy的孩子的头部不会大于大猩猩孩子的头部。
第三段给出一个可能的理论说明。一夫一妻。。。采集食物。。。直立行走。。。脑容增大/使用工具。如果不是使用工具者，那为什么要直立行走呢？一种理论是和家庭形式有关。可以让父母更好地采集食物、照顾幼儿。这样，直立行走可能很早就开始了。
答案 A
第一段的第一句就明白的说了Anthropologists once though…可以看出作者在陈述一个过去人们认同的观点或理解。
A.正确
B.一看compare locomotion就可以知道这是一个细节，不会是purpose
C.看关键词，nuclear family只出现在最后一段，是进一步陈述新观点的一个例子，细节，
D.看关键词 large brain developed 更晚。这个问题出现在全文关注的是walk这个行为，locomotion，而大脑有关的问题只是随便提到。从全文第一句话可以看出来：brain of increased size只是处于一个从句的地位。
E.看关键to illustrate the ..differences ，属于细节2.
曾认为，古人类大脑发展的同时学习使用工具，后来则开始直立行走。但考古发现表明先直立行走，继而大脑发展、运用工具。
第二段展开说明古人类双足行走的骨骼特点。
两足移动低效，因为肌肉用以进行平衡而非提供推进力了。骨骼也需相应调整。Lucy的髋骨和大腿骨更近于现代人类。Lucy的髋骨较人类宽扁，更适合双足行走，人类的髋骨则为生育大头后代的需要而变圆了。Lucy的孩子的头部不会大于大猩猩孩子的头部。
第三段给出一个可能的理论说明。一夫一妻。。。采集食物。。。直立行走。。。脑容增大/使用工具。如果不是使用工具者，那为什么要直立行走呢？一种理论是和家庭形式有关。可以让父母更好地采集食物、照顾幼儿。这样，直立行走可能很早就开始了。
答案 A
第一段的第一句就明白的说了Anthropologists once though…可以看出作者在陈述一个过去人们认同的观点或理解。
A.正确
B.一看compare locomotion就可以知道这是一个细节，不会是purpose
C.看关键词，nuclear family只出现在最后一段，是进一步陈述新观点的一个例子，细节，
D.看关键词 large brain developed 更晚。这个问题出现在全文关注的是walk这个行为，locomotion，而大脑有关的问题只是随便提到。从全文第一句话可以看出来：brain of increased size只是处于一个从句的地位。
E.看关键to illustrate the ..differences ，属于细节2.
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