美国科学60秒 SSS 2013-02-21
时间：2018-12-24 作者：英语课 分类：Scientific American(二)月
英语课
Naked skin or effectively naded skin has been the primary interface 1 between the human body and the environment for over 200,000 years.
Penn State anthropologist 2 Nina Jablonski on the evolution of human skin pigmentation at the annual meeting of the American Association for the Advancement 3 of Science in Boston on February 16th.
The variation in pigmentation is one of the most conspicuous 4 and interesting features of human skin. In fact that within one species we have a wide variation skin pigmentation from very dark to very light, and that this pattern has a sensible geographical 5 distribution that is related to the intensity 6 of UV radiation is highly significant.
Ultraviolate radiation exerts such negative effects, predominantly negative effects on the body, strong malinen pigmentation evolved to protect us from most of those negative effects.
Loss of pigmentation was one of the most conspicuous things that occurred in these few small populations of homosapiens that left Africa arround 17,000 years ago. So that we actually see depigmented skin evolving in the ancestors of Western Europeans and Eastern Asians independently as a a result of independent genetic 7 mutations, because this depigmented skin was very important to people living under low UV regimes. It allowed people to make Vitamin-D more easily out of available UV radiation in sunlight and it afforded tremendous evolutionary 8 advantages.
1 interface
n.接合部位，分界面；v.(使)互相联系
- My computer has a network interface,which allows me to get to other computers.我的计算机有网络接口可以与其它计算机连在一起。
- This program has perspicuous interface and extensive application. 该程序界面明了，适用范围广。
2 anthropologist
n.人类学家，人类学者
- The lecturer is an anthropologist.这位讲师是人类学家。
- The anthropologist unearthed the skull of an ancient human at the site.人类学家在这个遗址挖掘出那块古人类的颅骨。
3 advancement
n.前进，促进，提升
- His new contribution to the advancement of physiology was well appreciated.他对生理学发展的新贡献获得高度赞赏。
- The aim of a university should be the advancement of learning.大学的目标应是促进学术。
4 conspicuous
adj.明眼的，惹人注目的；炫耀的，摆阔气的
- It is conspicuous that smoking is harmful to health.很明显，抽烟对健康有害。
- Its colouring makes it highly conspicuous.它的色彩使它非常惹人注目。
5 geographical
adj.地理的；地区(性)的
- The current survey will have a wider geographical spread.当前的调查将在更广泛的地域范围內进行。
- These birds have a wide geographical distribution.这些鸟的地理分布很广。
6 intensity
n.强烈，剧烈；强度；烈度
- I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
- The strike is growing in intensity.罢工日益加剧。
7 genetic
adj.遗传的，遗传学的
- It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
- Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
8 evolutionary
adj.进化的；演化的，演变的；[生]进化论的
- Life has its own evolutionary process.生命有其自身的进化过程。
- These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。