首页
登录
职称英语
On Mother’ Day, it’s customary to speak about the sacrifices our mothers mad
On Mother’ Day, it’s customary to speak about the sacrifices our mothers mad
游客
2024-05-06
12
管理
问题
On Mother’ Day, it’s customary to speak about the sacrifices our mothers made to improve our lives. But mothers also deserve credit for the pivotal (关键的) role they’ve played in the history of human evolution. Prehistoric mothers did nothing less than seed the development of our species’ remarkable intelligence.
The story begins at least two million years ago, when our brains started to grow larger, eventually making humans the most cognitively advanced species on earth. This evolution was not without its difficulties, particularly for mothers. That’s because, some five million to seven million years ago, soon after the human lineage (世系) branched from the ancestors of chimpanzees (黑猩猩), another peculiarity increasingly came to mark our ancestors: walking upright on two legs, or bipedalism.
The evolution of bipedalism gradually altered our ancestors’ skeletons. By the time brain size began trending upward, the shape of the human pelvis (骨盆) had changed to accommodate the muscle attachments that facilitated walking (and running) in a more vertical posture. As a result, parts of the birth canal narrowed, making the passage of big-brained infants increasingly difficult.
The combination of big brains and constricted birth canals was an obstetrical problem for early mothers and no doubt led to high rates of maternal and infant mortality. The infants who survived were the ones whose heads were small enough to squeeze through narrowed birth canals, but to thrive outside the womb, human development favored big brains. And so natural selection encouraged the early birth of human fetuses, before they had finished gestating (孕育). For that reason, our babies are born in immature, helpless states compared with those of the apes.
Had it not been for the natural selection of enlarged brains, our species would have evolved in a completely different direction. There would be no theory of relativity, no knowledge of "entangled" particles or the human genome; we’d have no great art, music or novels. The excruciating (极痛苦的) pain and trauma of childbirth are the cost our species has paid for its fancy cognition. And mothers continue to pay the debt.
But that’s hardly all prehistoric mothers gave us. They also may well have touched off the evolution of language from the sounds they made to reassure their helpless infants. Baby chimpanzees, after all, can cling to their mothers’ hairy chests and contentedly ride along, nursing on demand. But human infants, born immature, lack that dexterity. Before the advent of devices like baby slings, the burden of carrying helpless infants presented a dilemma for early mothers as they foraged for food and water. [br] Human babies are born in immature, helpless states, owing to ______.
选项
A、the early birth of human fetuses
B、the big brains of the fetus
C、the constricted birth canals of the mother
D、both big brains and constricted birth canals
答案
A
解析
参见文章第4段:And so natural selection encouraged the early birth of human fetuses, before they had finished gestating. For that reason, our babies are born in immature, helpless states compared with those of the apes.其大意是,因此自然淘汰鼓励了人类胎儿的早出生,在他们尚未孕育完之前就出生。正是由于此原
转载请注明原文地址:https://tihaiku.com/zcyy/3586288.html
相关试题推荐
【B1】[br]【B19】A、abandonsB、cherishesC、sacrificesD、reconcilesC由于商人急于想成功,他可能置自
OnMother’Day,it’scustomarytospeakaboutthesacrificesourmothersmad
OnMother’Day,it’scustomarytospeakaboutthesacrificesourmothersmad
OnMother’Day,it’scustomarytospeakaboutthesacrificesourmothersmad
OnMother’Day,it’scustomarytospeakaboutthesacrificesourmothersmad
[originaltext]MotheringSundayintheUKistheequivalentofMother’sDay
[originaltext]MotheringSundayintheUKistheequivalentofMother’sDay
[originaltext]MotheringSundayintheUKistheequivalentofMother’sDay
[originaltext]IntheUnitedStates,itisnotcustomarytotelephonesomeon
TheMartianmoonPhobosmayhavebeenblastedoffitsmotherplanetbyavio
随机试题
Youshouldnotfearspidersbecauseoftheirpoison.OfallthespidersinNorth
[originaltext]Ourenvironmentisbeingpollutedfasterthanthenatureand
有线或无线网络是传感器与传感器之间、传感器与观察者之间的通信方式,用于在传感器与
维生素C在解毒过程中主要是提供( )。A.羟基 B.羧基 C.甲基 D.
可与金石、贝壳等同用,以助其消化的药物是()A.香附 B.麦芽 C.神
A.缩短心房的ERP B.抑制房室传导,打断房室结区的折返 C.增加房室结的
某研究小组在1984年挑选了10万名身体健康的志愿者,在2010反馈调查中,超过
在经济运行过程中,阻碍互惠交换不能实现的主要障碍包括( )。A.信息障碍 B
2017年1月1日,某企业“坏账准备——应收账款”明细科目贷方余额为8万元,当期
曲线y=sinx(0≤x≤π/2)与直线x=π/2,y=0围成的平面图形绕x轴旋
最新回复
(
0
)