------

1369179610

译文校正：be correlated with  被联系起来
temptation 诱惑
cryon（s）彩色蜡笔或粉笔
sticker  贴纸


a sheet of paper  一张纸
a set of art supplies


gratification 满意的事

1369179610

BL 7-L3   CN I

通过研究化石，我们可以知道地球上生命的历史。有趣的是，它似乎在很长时间之内都没有发生什么变化。之后断断续续的，其间有物种的大灭绝以及之后尾随而来的种群的多样化的（一系列）简短时期开始蓬勃。他们是怎么发生的？嗯，有的时候栖息地会被破坏，或环境会改变。你知道若大洋的温度即便仅仅下降几度，很多物种就会死吗？难以置信，对吗？或者，即使环境是相对稳定的，生物条件（也）会随其他物种行不同方向进化而改变。例如，我们看，当一个相似的物种进化出了一个壳，那么相关的没有壳的物种作为其他物种的变化的结果，可能就更易受捕猎者的攻击，并濒临灭绝。所以你可以看见，那个灭绝是历史的自然结果，它是，嗯，不可避免的。但是有的时候，大规模的灭绝发生，并且大多数已知的物种消失，这就很不同了。


让我讲一下两个这样的灭绝。第一个，二叠纪大灭绝，发生在2500万年前。根据化石记录，多余90%的海洋物种还有约30%的昆虫目消失了。然后大约65万年前，新生代大灭绝夺走了一多半的海洋物种和许多陆生植物和动物，包括恐龙。


那么什么导致的大规模灭绝呢？这不是一个容易回答的问题，你看，很显然在化石记录上，这些物种存在于某个地理时期，并在之后消失。这个我们是有充分证据的，但是，它们为什么消失，这就比较值得揣测了。在二叠纪，几个极端的条件可能同时发生了，包括几个大陆融合成一大块土地。你可以想象，这样的激进的大陆和水源的分配变化，会影响到栖息地（环境），并导致灭绝。也有证据显示在这个时期火山活动已经产生足量的二氧化碳导致全球变暖，这转而影响温度和海洋的深度。然后它，我是说全球变暖，很可能也导致了海洋中的含氧量下降。所有这些条件聚集在一起，可以同时灭绝巨量的物种。这就是大灭绝。


并且相似的一套条件在新生代可能也会导致大灭绝。我们可以收集数据说明大陆大陆漂移，它沿着海岸线随着向外流走的海水移动。另外，我们知道变冷的天气很可能是，至少是部分的，火山喷发频繁的结果。这些火山喷发很可能释放了足够多的物质到大气中遮挡了阳光。说了这么多，许多科学家现在赞成一个非常不寻常的假设，他们推论，很可能是一个很大的小行星撞击了地球--即所谓的撞击假说主张。推测有两个事件导致了大规模灭绝。首先撞击很可能导致了非常大面积的爆炸，以至于北美的大多数生命在几分钟之内死亡。第二，他们假设，大量的浮尘一定遮蔽了太阳光，并且这个撞击，事实上，的确达到可以让地球变暗，我们说的事几个月，甚至几年。所以，黑暗的结果，我是说，会导致光合作用减弱在未来会带来食物链的断裂。目前，这个削弱一定影响很多物种。


所以对撞击假说的支持，他们提供了证据，一薄层的粘土非常富含铱，可以在区分中生代时期和新生代时期的地理物质中发现。精确地说，是新生代灭绝时期。那么，这粘土有神马特殊之处？铱是一种在地球上非常稀有的元素。但是它的含量在小行星和其他已经分析的外来陨石中是地球的两倍。所以这些沉淀很可能是撞击留下来的。在西半球物种灭绝更加严重这个事实，也可以根据撞击以及黑云导致撞击附近地区的大量酸性降雨来解释。或者是同时发生了几个大的灾难，扰乱了星球的平衡。


顺便说下，不论（灭绝的）原因是什么，事实是大规模灭绝是的的确确发生了。并且它们影响了深远的影响了我们星球上的物种多样性。幸存下来的物种，不论是因为它们有基因优势，或者是因为它们幸运地离灾难发生处足够远，这些物种变成了现在在生物演化历史上扮演重要角色的物种的祖先。

1369179610

BL 7-L3   EN I

Listen to part of a lecture in a biology class.Interestingly enough,it appears that there are long periods in which not very much changes occurs.Then sporadic brief period,in which there are mass extinctions of species followed by diversification of the groups that survived.How did this happen?Well,sometimes a habitat destroyed,or the environment changes,did you know that if the temperature of the ocean falls by even a few degrees,many species will die?Incredible,isn't it?Or even when the environment is relatively stable,biological conditions can change when other species evolve in different directions.For example,..when the similar species evolved by developing a shell,then the related species without shells may be more vulnerable to predators and could become extinct,as a result of changes in the other species.So you can see that extinctions of natural consequences of history.It's,well,inevitable.But sometimes,mass extinctions occurred,and most of the known species are lost.And this is very different.Let me mentioned two such mass extinctions.First,the Permian mass extinction,which occurred about two hundred and fifty million years ago.According to fossil record,more than ninety percent of the marine species,and about forty percent of the orders of insects, perished.Then about 65 million years ago,the Cretacious mass ...more than half of the marine species.and many terrestrial of plants and animals,including the dinosaurs.So what causes mass extinctions,

This isn't an easy question to answer,you see,

It's obvious from the fossil record the species exist,there is a certain theological time period.And then they disappear.And you have solid evidence for that.But why did they disappear is well more speculative.In the Permian,several extreme conditions may have converged including the emerging of the ..into one large land mass.you can imagine,such a radically change in the  distribution of land in ..would have disturbed the habitats and caused the climate to change.There's also evidence that the volcanic activity during this period may have produced enough carbon dioxide to cause global warming,which in term would have affected the temperature and the depth of the ocean.And it,..here to global warming,So it probably also caused the oxygen levels in the ocean to decrease.all of these conditions could have converged to extinguish an enormous number of species at the same time.That's mass extinction.And the similar set of the conditions may also have contributed to the mass extinction in the Cretacious periods as well.We can gather data that convinces us about the continental drift.That it occured along with,receding scenes along the continental coastlines.In addition,we know that cooler climate was probably the result.At least in part,of increase volcanic eruption.And these eruptions probably release enough material in the atmosphere to block the sunlight.Have..all of that.Maybe scientists now favor a different hypothesis,they theorize,that maybe a large asteroid collide with the Earth.As it ...be so called impact hypothesis.speculate that there are two events that called the mass extinction.First,impact that may cause the fire storm,of such proportion of most of the light in North America,would have been de..within minutes.Second,they postulate.That it ...cloud of fallout could have blocked the sunlight.and that the impact was in fact,large enough to darken the earth.And we are talking about months or even years.So the result of the darkness,I mean,that would have caused the reduction of the photosynthesis.Would just turn with a distruction in the future.Now,such ...would have affected many species.So the advocates of the impact of the hypothesis,they put forward an evidence that a theme layer a the clay which in iridium deposit,can be found in the geologic material that separate the mesozoic and the Cenizoic ears.precisely the time period or the Cretacious of mass extinction.So what's special about this clay,well,iridium is a very rare element on Earth.But it's quite common in mideorite, and other extra terrestrial debris that have been analyzed.So it's possible that this settlement is the remains of the impact.The fact,that there was more serious damage to the species in the western hemisphere,that also be explained by the point of this p...and the fact that the dark cloud could have caused more ..presipitaton,nearer the area of impacts.Or there may have been a number of ...that ..the ..contaneously.the ...planetary balances.But whatever the cause or cuases,the fact remains that the mass extinction that occurs.And they influenced the biological diversity of all planetary of ..ways.The species that survive,whether because they have genetic advantages,or because they were fortunately enough to be farther from catastrophes.These species became the ancestors of the species that have played important roles,in biological evolutionary history.  

1369179610

BL 7-L3     CN II

首段：化石--生命的历史--没变化；大灭绝；多样化。

    （灭绝）怎么发生的？

      正常：1.环境2.进化中的淘汰
      不正常：大灭绝



第二段：两个大灭绝--1.二叠纪大灭绝；2.新生代大灭绝



第三段：产生原因：不好说，
       例如：    二叠纪，
                 2个极端条件：1.大陆融合；
                              2.火山喷发-全球变暖-温度，海平面高度，海水含氧量



第四段：新生代大灭绝原因：
                 小行星撞地球，1.当场撞死了一批倒霉蛋。
                               2.尘埃要时间沉淀，↓光合作用，温度↓，食物链断裂。



第五段：撞击假说的证据：粘土含铱。  不过也可能和二叠纪一样，几个灾难同时发生。



第六段：大灭绝是存在的，幸存的动物变成了演化史上重要角色的祖先。

1369179610

BL 7-L3   EN II



Listen to part of a lecture in a biology class.By studying the fossil record we can read the history of life on Earth.Interestingly enough,it appears that there are long periods in which not very much change occurs.Then sporadic brief periods in which there are mass extinctions of species followed by diversification of the groups that survived.How does this happen?Well,sometimes a habitat is destroyed,or the environment changes.Did you know that if the temperature of the ocean falls by even a few degrees many species will die?Incredible,isn't it?Or, even when the environment is relatively stable,biological conditions can change when other species evolve in different directions.For example,let's see,when a similar species evolves by developing a shell,then the related species without shells may be more vulnerable to predators and could become extinct as a result of changes in the other species.So you can see that extinction is a natural consequence of history.It's, well,inevitable.But sometimes mass extinctions occur,and most of the known species are lost.And this is very different.



Let me mention two such mass extinctions.First,the Permian mass extinction,which occurred about 250 million years ago,according to fossil records,more than ninety percent of the marine species,and about 30 percent of the orders of insects...perished.Then about 65 million years ago,the Cretaceous mass extinction claimed more than half of the marine species and many terrestrial species of plants and animals,including the dinosaurs.

So what causes mass extinction?This isn't an easy question to answer.You see,It's obvious from the fossil records that the species exist during a certain geological time period,and then, they disappear,and we have solid evidence for that.But why they disappear is,well,more speculative.In the Permian,several extreme conditions may have converged,including the merging of the continents into one large land mass.As you can imagine,such a radical change in the distribution of land and water would have disturbed habitats and caused the climate to change.There's also evidence that volcanic activity during this period may have produced enough carbon dioxide to cause global warming,which in turn would have affected the temperature and depth of the oceans,and it,and I'm referring here to global warming,so it probably also caused the oxygen levels in the oceans to decrease.All of these conditions could have converged to extinguish an enormous number of species at the same time.That's mass extinction.

And a similar set of conditions may also have contributed to the mass extinction in the Cretaceous period as well.We can gather data that convinces us about continental drift.That it occurred along with receding seas along the continental coastlines.In addition,we know that cooler climate was probably the result,at least in part,of...increased volcanic eruptions,and these eruptions,probably released enough material into the atmosphere to block the sunlight.Having said all of that,many scientists now favor a very different hypothesis.They theorize that maybe a large asteroid collided with the Earth.Advocates of the so-called impact hypothesis,speculate that there were two events that caused the mass extinction.First,the impact probably caused the a fire storm of such proportion that most of the life in North America would have been decimated within minutes.Second,they postulate that an enormous cloud of fallout could have blocked out the sunlight and... that the impact was, in fact,large enough to... darken the Earth...and we are talking about months or even years.So the result... of the darkness, I mean...that would have caused a reduction in photosynthesis,which,in turn,would have created a disruption in the food chain.Now,such a disruption,would have affected many species.

So the advocates of the impact hypothesis... they put forward evidence that a thin layer of clay, rich in iridium deposits,uh,can be found in the geologic material that separates the Mesozoic and the Cenozoic eras--precisely the time period for the Cretaceous mass extinction.So what's special about this clay?Well,iridium is a very rare element on Earth,but it's quite common in meteorites and other extraterrestrial debris that's been analyzed.So it's possible that this sediment is the remains of the impact.The fact that there was more serious damage to the species in the Western Hemisphere could also be explained by the point of impact,and the fact that the dark cloud could have caused more acidic precipitation nearer the area of impact.Or,there may have been a number of calamities that converged simultaneously,disrupting planetary balances.

But whatever the cause or causes,the fact remains that the mass extinctions occurred,and they influenced the biological diversity of our planet in profound ways.The species that survived, whether because they had genetic advantages or because they were fortunate enough to be farther from the catastrophes...these species became the ancestors of the species that have played important roles in biological evolutionary history.  

1369179610

BL 7-L3   总结帖

sporadic  不定时发生的
periods   时期
diversification of the group  种群多样性


Cretaceous  白垩纪的
claim 要走了，带走了
terrestril 陆地的


converge 聚集
radical 根本的，基本的
receding 逐渐远离的
theorize 创立理论，建立学说
Mesozoic 中生代的
Cenozoic 新生代的
debirs 碎片，残骸
acidic precipitation 酸性降雨



起承转合 挺好用的啊。

1369179610

tpo 18-lecture 4  CN I

嗯，春天好像终于来了啊~最后的一场冬雪也要在几天内消融了。所以在结束今天的课程之前，我想讲一个生物现象，（它是）冬天到春天的转变的一部分。这事你可以出去自己观察，如果你有耐心的话。有一个在这里生活的很小的生物，你没准见过它，它是北美树蛙。树蛙没那么容易看见，因为它呆在离地面非常近的地方，它呆在树叶或其他东西下面，伪装的十分像周围的环境，就像你将看到的那样。但是它们值得（你）这些努力，因为它们做一些非常不寻常的事情，一些你没准觉得根本不可能的事情。好了，北美树蛙生活在非常广泛的土地上火范围内。它们可以在整个的美国东北部被找到，整个加拿大和阿拉斯加，甚至是在北极圈之内。没有其他的青蛙可以在这么北的地方生活。但是，不论生活在哪里，一旦天气开始变冷，并且温度开始降至零度以下，只要青蛙触碰到了冰晶或者冰冻的土地，嗯..它就开始冰冻了！真的~你们看起来有点大吃一惊呀。等一下。你是说它冰冻成一坨的时候仍然是活的？嗯...差不多吧。冰进驻了细胞以外的所有地方，但是从未进入细胞内部。但是，它的心脏怎么跳呢？它不跳。但是，它怎么能..你打算试一试吗？第一次触碰冰显然是青蛙体内生物反应的启动诱因。首先它的身体中枢开始脱水，即青蛙的中枢部分：它的内部脏器，它的心脏，肝脏，肺，这些脏器变得越来越干，而被挤出来的水分汇成一个水泡围在脏器周围，就在它的皮肤之下。之后，这一团水开始结冰。好了，我们大家都知道，青蛙的心脏还在跳，对吧？越来越慢，但是...在它完全冻住前的最后几小时，心脏运送葡萄糖，一种血糖，至全身循环系统，就像防冻剂似的。就像你冬天放进汽车的那种防冻液？嗯~你说呢？在青蛙的内部，这种葡萄糖让细胞内部在冬天变得更难冰冻。所以细胞总是保持微微湿润。这样它们好能在冬天幸存。在这之后，它的心脏就彻底停止跳动了。所以，事情就是这样的对吗？我不清楚，但是它要那样呆多久？嗯，可以是几天甚至是几个月，事实上是整个冬天。但是它的心脏不再需要任何跳动，因为它的血液也被冻住了。我就是不明白，它怎么就不是死了呢？嗯，这就是令人惊奇的地方。并且它再次苏醒也很让人惊奇。几个月没有心跳之后，春天再次来临，土地回暖。然后突然有一天，呯！一个脉动。然后又一下。然后又一下直到10-12小时之后，这东西就完全苏醒了。那么，解冻过程也有诱因吗？事实上，我们不是很确定。比较确定的事情是，即使是太阳在外头警告它起来，它的里面首先解冻。即先心脏，大脑，然后所有地方。但是不知怎的它就是在每年春天那样发生。但是它们解冻之后会不会影响它们的寿命？嗯..我们真的不知道树蛙通常活多久，很可能只是几年。但是没有证据说这种冰冻会影响它们的寿命，虽然它的确有一些别的影响。在研究过程中，我们发现，当涉及到繁殖的时候，冰冻减弱了雄性的交配行为。在它们冰冻之后，当然又苏醒了，它们好像没什么动静。它们行动迟缓，好像也很难认出潜在的交配配偶。所以，若一只雄性青蛙成功地没进入冰冻，它很可能会有更成功的交配。

1369179610

tpo18-L4

Listen to part of a lecture in a biology class.Well,it's finally looking like the spring is arriving.A last of the winter snow would be melting away in a few days.So before we close today I thought I've mentioned a biological event that's part of the transition from winter to spring.Something you can go outside and watch if you have some patience.There's a small creature that lives in this area,you've probably seen it.It's the North American wood frog.Now the wood frog is not that easy to spot since they stay pretty close to the ground.under leaves and things and they blend really well with the background as you can see.But they are worth the efforts,because they did something very unusual,something you might not have even thought possible.Ok,North American wood frogs live over a very large broad territory or range.They are found all over the Northeastern United States and all through Canada and Alaska,even inside the Artic Circle.No other frog is able to live that far north.But wherever they live,once the weather starts to turn cold,and the temperature starts to drop below freezing,as soon as the frog even touches an ice cristal or the frozen ground,well,it begins to freeze.yeah,yes to me,you look a little bit taken aback.Wait.You mean that it's still alive but it freezes,solid?Well,almost.Ice forms in all the spaces in the outside the cells,but never within a cell.But,then how does its heart beat?It doesn't.But how could the heart...?You are gonna do such a thing?Well,that first touch of ice apparently triggered a biological response inside the frog,That first of all,frogs drop its water  away from the centre of its body,so the middle part of the frog,its interal organs,its heart,lungs,liver,these are getting dryer and dryer,while the water that being pulled away,is forming a puddle around the organ just under its skin.and then that puddle of water starts to freeze.Ok,up to know the frog's heart is still beating right?Slower and slower,and the last few hours before it freezes,it distributes glucose,a blood sugar throughout its body,its circulatory system.So it acts like an antifreeze.A solution of antifreeze like you put in your car in winter?Well,you tell me.In frogs,the extra glucose makes it harder for the weather inside the cells to freeze.So the cells they just slightly wet,so they can survive the winter.Then after that,the heart stops beating all together.so,is that the same?I don't really know,but how long do they stay that way?Well,it could be days,or even months,all winter in fact.But see the heart really doesn't need to do any pumping now because the blood is frozen,too.I just ,I guess I just don't see how it isn't..you know ...clinically dead.Well,that's the amazing thing.And how it revive is amazing,too.After months without a heartbeat,springtime comes surround again,the Earth starts to warm up and suddenly one day,ping!a pulse..pulse.another one,and another one until maybe ten or twelve hours later the animal is fully recovered.And does the uh,thrawing process has some kind of trigger as well?Well,we are not sure actually,the clearer thing is even the sun is warming the frog up on the outside,it's inside thraw first.the heart the brain and everything.But somehow it all just happen that way every spring.An active  thraw affect them like their lifespan?Well,hum,we really don't know a lot about how long the wood frog normally lives.Probably just a few years.There's no evidence that the freezing process affects the longevity.It does have some other impacts though.In studies,we found that when it comes to a production,freezing diminishes the mating performance of male.After they've been frozen and thraw of course,they don't seem quite as vocal.They move slow and they seem to have a harder time recognizing a potential mate.So if a male frog can manage not to go to this freezing cycle,he will probably have a more successful mating.

1369179610

tpo18-L4   CN II

W：树蛙--生活在NA,CA,ALSK   靠近地面--它们会自己把自己冻起来。
M：它还活着？
W：对 细胞没冻上
M:  那它心脏怎么跳？
W：不跳
M：……
W：具体自冻方式：    碰了一个凉东西--脱水--器官变干--挤出的水结冰--心跳变慢，输送糖保证细胞不被冻上--心跳停
M：它要把自己东多久？
W：整个冬天。心脏不跳。
M：怎么就没死呢？
W：这就是惊人之处……解冻模式：春天来，温度升--脉动--10-12小时后活过来
M：有触发诱因吗？
W:不知道。但我知道它由内到外解冻。
M：它的寿命会缩减吗？
W：还是没证据。不过，交配繁殖会受影响。


大概在陈述的时候知道主题，记清楚问题和答案，整片文章就都下来了。

1369179610

tpo 18-L4     EN II

Listen to part of a lecture in a biology class.Well,it's finally looking like the spring is arriving.A last of the winter snow would be melting away in a few days.So before we close today I thought I'd mention a biological event that's part of the transition from winter to spring.Something you can go outside and watch if you have some patience.There's a small creature that lives in this area,you've probably seen it.It's the Northern American wood frog.Now the wood frog is not that easy to spot since they stay pretty close to the ground.under leaves and things and they blend in really well with the background as you can see.But they are worth the effort,because they did something very unusual,something you might not have even thought possible.Ok,Northern American wood frogs live over a very large broad territory or range.They are found all over the Northeastern United States and all through Canada and Alaska,even inside the Arctic Circle.No other frog is able to live that far north.But wherever they live,once the weather starts to turn cold,and the temperature starts to drop below freezing,as soon as the frog even touches an ice crystal or a bit of frozen ground,well,it begins to freeze.yeah,yes to me,you look a little bit taken aback.Wait.You mean that it's still alive but it freezes,solid?Well,almost.Ice forms in all the spaces in the outside the cells,but never within a cell.But,then how does its heart beat?It doesn't.But how could the heart...?You are gonna do such a thing?Well,that first touch of ice apparently triggered a biological response inside the frog,That first of all,frogs drop its water  away from the centre of its body,so the middle part of the frog,its internal organs,its heart,lungs,livers,these are getting dryer and dryer,while the water that being pulled away,is forming a puddle around the organs just underneath its skin.and then that puddle of water starts to freeze.Ok,up to know the frog's heart is still beating right?Slower and slower,and the last few hours before it freezes,it distributes glucose,a blood sugar throughout its body,its circulatory system.Sort of acts like an antifreeze.A solution of antifreeze like you put in your car in winter?Well,you tell me.In frogs,the extra glucose makes it harder for the weather inside the cells to freeze.So the cells they just slightly wet,so they can survive the winter.Then after that,the heart stops beating altogether.so,is that the same?I don't really know,but how long do they stay that way?Well,it could be days,or even months,all winter in fact.But see the heart really doesn't need to do any pumping now because the blood is frozen,too.I just ,I guess I just don't see how it isn't..you know ...clinically dead.Well,that's the amazing thing.And how it revive is amazing,too.After months without a heartbeat,springtime comes surround again,the Earth starts to warm up and suddenly one day,ping!a pulse..pulse.another one,and another one until maybe ten or twelve hours later the animal is fully recovered.And does the uh,thawing process has some kind of trigger as well?Well,we are not sure actually,the peculiar thing is even the sun is warming the frog up on the outside,its inside thaw first.the heart the brain and everything.But somehow it all just happen that way every spring.And after they thaw affect them like their lifespan?Well,hum,we really don't know a lot about how long the wood frog normally lives.Probably just a few years.There's no evidence that the freezing process affects the longevity.It does have some other impacts though.In studies,we found that when it comes to a reproduction,freezing diminishes the mating performance of male.After they've been frozen and thawed of course,they don't seem quite as vocal.They move slower and they seem to have a harder time recognizing a potential mate.So if a male frog could manage not to go through this freezing cycle,he will probably have a more success in mating.