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
10
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
HowtoBuildYourVocabularyEffectivelyVocabularyist
[originaltext]M:Hello,Amy.Areyoucomingtomybirthdayparty?W:Yes,lam.
Allthetrees(plant)______lastsummer.wereplanted本题考查被动语态。根据句意应该是“树被种”,而且其中含
在著作权贸易中引进选题时,主要应考虑的因素包括( )等。A.原作品在原市场的反
劳务纠纷发生后,双方当事人都可以自知道或应当知道其权利被侵害之日起的()日内,
以下哪一种先天性畸形用B超检查难以显示A.先天性肾缺如 B.腹壁缺损 C.小
男性,37岁。间断性腹泻10余年,加重1个月,大便每日近10次,不成形,近日食欲
变压器的哪些保护装置应投信号()本体轻瓦斯$;$突发压力继电器$;$压力释放阀$
=5.6X10-12,则Mg(OH)2在0.01mol*L-1NaOH溶
引起药源性疾病的因素包括A.遗传因素 B.药物因素 C.性别因素 D.年龄
最新回复
(
0
)