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 likethe 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 theory mentioned in lines 35–38 suggests that which of the following was true for the hominid ancestors of modern humans before they made the transition to walking upright?
Their brains were smaller than the brains of present-day chimpanzees.
They competed rather than cooperated in searching for food.
Their mating patterns and family structure were closer to those of present-day chimpanzees than to those of modern humans.
Males played a more significant role in child rearing than they played after the transition to walking upright.
Females’ ability to nurture and protect their offspring was limited by the need to find food for themselves.
此讲解的内容由AI生成,还未经人工审阅,仅供参考。
正确答案是 D。理由是,文章中提到,走路改变了男性在育儿方面所扮演的角色,因为他们能够使用双手去收集食物并把它们送到他们的伴侣那里,从而让母亲有更多的时间和精力来关心和保护他们的孩子。因此,走路之前,男性在儿童抚养方面扮演的角色比走路之后更加重要。
devote more time to nurturing and protecting→之前female也需要找食物,直立行走使得找食物的时间减少了,多出来的时间可以nuture和protect。
d
Females’ ability to nurture and protect their offspring was limited by the need to find food for themselves.
怎么读怎么别扭,就是 女性为自己寻找食物的需求 限制了 女性的哺育保护后代的能力,但是文中不是说男性找到食物给女性吗?没说道女性需要自己去找食物啊?如果这句话反过来说还可以理解
有人可以解释一下吗?
Because fathers were able to use their hands to gather food and carry it to their mates from a distance. This allowed mothers to expend greater amounts of time and energy to the nurture and protection of their children.
This implies that before this development mothers had to spend more time acquiring their own food, and therefore less time nurturing and protecting 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. 这里说直立行走允许父亲使用他的手来收集食物并且从较远距离带回给他们的配偶,进而允许母亲投入更多的时间和精力陪养育和保护他们的孩子
这说明与原来四只脚走相比的时候,她们有更多的时间和精力,说明原来的时候母亲也会去找食物
问的是在直立行走的转变发生前的情况。直立行走后男鞋可以带事物给女性,女性专心带孩子。allowing the mother to devote more time and energy to nurturing and protecting their children. more说明直立行走前没那么时间和精力花在带小孩上。
问的是直立行走的转变发生前的情况,你说的是直立行走后的。allowing the mother to devote more time and energy to nurturing and protecting their children. more说明之前要更少。
登录 或 注册 后可以参加讨论
a不切题,且定位中最后一段根本没提及;还是在定位段去找符合题意的