首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A、Leaves and grass. B、Man-made shelter. C、Their skin coloring. D、Hair on their skin. C讲座中提到,跟猿类和猴子相比,我们的毛发非常少。大多数动物用毛发保护自己不受日晒,而
A、Leaves and grass. B、Man-made shelter. C、Their skin coloring. D、Hair on their skin. C讲座中提到,跟猿类和猴子相比,我们的毛发非常少。大多数动物用毛发保护自己不受日晒,而
admin
2021-01-08
39
问题
Skin may seem like a superficial human attribute, but it’s the first thing we notice about anyone we meet. As a zoologist focusing on the studies of apes and monkeys, I’ve been studying why humans evolved to become the naked ape, and why skin comes in so many different shades around the world. We can make a very good estimate from the fossil record that humans probably evolved naked skin around 1.5 million years ago, and meanwhile they mostly lost their coat of fur.
Today we have a few patches of hair remaining on various parts of our bodies. But compared with apes and monkeys, we have very little. Basically, we turned our skin darker to serve as a natural sun protector in the place of the hair we lost. We think we lost this hair because of the need to keep ourselves cool when we were moving around vigorously in a hot environment. We can’t really lose heat by breathing quickly and loudly like dogs. We have to do it by sweating. So we evolved the ability to sweat plentifully and lost most of our fur. Most animals protect themselves from the sun with fur. What we did in our ancestry was to produce more permanent natural coloring in our skin cells. This was really an important revolution in human history because it allowed us to continue to evolve in equatorial environments. It really made it possible for us to continue along the path toward modern humans in Africa.
For most of human history, we all had dark skin. What we see today is the product of evolutionary events resulting from the dispersal of a few human populations out of Africa around 60,000 to 70,000 years ago. Our species originated around 200,000 years ago and underwent tremendous diversification— culturally, technologically, linguistically, artistically— for 130,000 years. After that, a few small populations left Africa to populate the rest of the world. These early ancestors of modern Eurasians dispersed into parts of the world that had more seasonal sunshine and much lower levels of sun radiation. It’s in these populations that we begin to see real changes in the genetic makeup of natural coloring.
Today, skin color is evolving in the new mixtures of people coming together and having children with new mixtures of skin color genes. We can see this in almost every large city worldwide. Not only the coloring genes but lots of other genes are getting mixed up, too.
Questions 22 to 25 are based on the recording you have just heard.
22. What does the speaker mainly talk about?
23. What had probably caused humans to lose most of their hair 1.5 million years ago?
24. What does the speaker say protected early humans from the sun?
25. What happened after humans migrated from Africa to other parts of the world?
选项
A、Leaves and grass.
B、Man-made shelter.
C、Their skin coloring.
D、Hair on their skin.
答案
C
解析
讲座中提到,跟猿类和猴子相比,我们的毛发非常少。大多数动物用毛发保护自己不受日晒,而我们的祖先所做的是在我们的皮肤细胞中产生永久的天然色素。我们的皮肤颜色会变深,加深的肤色是对日晒的天然防护。因此答案为C)。
转载请注明原文地址:https://kaotiyun.com/show/BiP7777K
0
大学英语六级
相关试题推荐
Peopleatthelowerendoftheincomescaletakemorepleasureintheirrelationshipsandenjoycaringforandconnectingwitho
A、Consumptionandtheimpactontheenvironment.B、Socialstability.C、Economicdevelopment.D、Culturalprosperity.A
A、Theycanrecognizethedifferencebetweentwolanguages.B、Theycanonlyidentifythesoundsofthenativelanguage.C、Theyca
北京观光客自然都会游览故宫和长城,这是因为故宫和长城是举世闻名的旅游景点。然而,对于北京第三大旅游场所——北京世界公园,人们却知之甚少。北京世界公园于20世纪90年代初竣工,占地面积46.7公顷,分为17处风景区,收集了各个洲的主要名胜景点。北京世界公园的
Reebokexecutivesdonotliketoheartheirstylishathleticshoescalled"footwearforyuppies(雅皮士,少壮高薪职业人士)".Theycontendtha
Anewstudyfindsthatevenmildstresscanaffectyourabilitytocontrolyouremotions.AteamofneuroscientistsatNewYork
中国的桥梁建设有着悠久的历史。中国古代桥梁以木材和石头为主要建筑材料,形式多样,极富特色。中国现存最古老的桥梁为隋代建造的安济桥,位于河北省赵县。安济桥又名赵州桥,桥长50.82米,桥宽9米,为国家重点保护的文物(culturalrelic)。清朝末年,
A、Itwascreatedmainlyforscientificresearch.B、Itworksbetterinfineweatherconditions.C、Itmustbelocatedonatleast
A、Thereisagreatdifferencebetweenreadingandlistening.B、Thereareeffectivewaystopracticetheproofreadingskill.C、Hi
A、Itwasself-defeating.B、Itwasaggressive.C、Itwastheessenceofcomedy.D、Itwassomethingadmirable.B
随机试题
切割修理车身梁、车门槛板、A立柱、B立柱,均采用__________。
肺结核术后继续抗结核治疗至少需要多长时间()
A.透脓散B.瓜蒌牛蒡汤C.龙胆泻肝汤D.四妙汤加味E.托里消毒散治疗乳痈溃后热退身凉,肿痛渐消,应首选
施工组织设计完成后,按专用条款的约定,将施工进度计划和施工方案说明报送()审批。
耙吸式挖泥船的施工方法依泥浆处理方式的不同可分为()。
以下关于速动比率的说法中,错误的是()。
水俣病和痛痛病分别由()过量而引起。
阅读下面的文字,回答下列问题。玛雅人是中美洲的土著居民,曾经拥有与大河流域的古代文明同样高度发达的文明。大约从公元300年起,玛雅文明进入了被称为“古典期”的鼎盛时期。公元800年起,古典期玛雅文明到达了它的顶峰,随后发生了不可思议的崩溃。在此后
根据下列材料回答下列问题。2008年以来,世界经济增长速度全面放缓。2008年美国前三季度GDP环比分别增长O.9%、2.8%和下降0.5%;欧元区第一季度GDP环比增长0.7%,第二季度和第三季度均下降0.2%;日本第一季度GDP环比增长O.6%
对于一个一直以来学习成绩很差的学生,当在一次考试中取得较好的成绩时,教师引导其进行合适的归因,下列选项能取得最佳教学效果的归因是()。
最新回复
(
0
)