美国科学60秒 SSS 2013-02-19
时间：2018-12-24 作者：英语课 分类：Scientific American(二)月
This is scientific American's science 60 second science, I am steve mosbyA lot of people have had compacted third molars. Third molars produce chronic 1 pain. Allen man, a Princeton University Physical anthopolegist, the annual meeting of the immagrate association for the advanced science in boston on Feb 15th, Some thousands of years ago, there were a round of mutation 2, It was pressed the calcification 3 of the third molor of wisdom. So many of you, many of your children, have grown to adult with ad-period the third molars. Now that particular mutation has XX frenquency, so that some population more than 40% of people have one of more abs third molars. So you might ask the question: how did that develop because obviously you have the compact third molar if you follow survive of the XX then you are not gonna fall over folding your mouth and dying in agony. Reproduction of the fitis is what is all about, in other words, differential reproduction how will this work well. In the evening person who has had serious chronic pain with impact third moloar pephaps lower third molors, impacting into the multipulate conon causing a lot of pain, the company come up and says: how about we reproduction here. and the person says: not tonight dear my chew is killing 4 me. That is effect in evolutional senorio. Becaus that will produce fewer all spring in those people that frenquency of this feature would increase over time. Thanks for the munite for scientific american's 60 second science.
that particular mutation
- Famine differs from chronic malnutrition.饥荒不同于慢性营养不良。
- Chronic poisoning may lead to death from inanition.慢性中毒也可能由虚弱导致死亡。
- People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
- So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。
- This may be associated with intraabdominal calcification. 与此同时，腹腔内可能发现钙化。 来自辞典例句
- Peritoneal calcification and pseudocyst are described when perforation occurs. 在发生穿孔的时候可有腹膜的钙化和假囊肿形成。 来自互联网