HendrikPoinar_2013X[Hendrik Poina][寻回长毛猛犸].pdf

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1、www.XiYuS锡育软件When I was a young boy,I used to gaze through themicroscope of my father at the insects in amber that he keptin the house.当我还是个男孩时 我经常从爸爸的显微镜里观察他放在家里琥珀中的虫子00:12And they were remarkably well preserved,morphologicallyjust phenomenal.它们保存得很好 看上去挺壮观的00:20And we used to imagine that someday,

2、they would actuallycome to life and they would crawl out of the resin,and,ifthey could,they would fly away.我们曾幻想某天 他们会在现实中复苏 并爬出这些树脂 或许还会飞走00:25If you had asked me 10 years ago whether or not we wouldever be able to sequence the genome of extinct animals,十年前如果你问我 能否找出这种灭绝了的生物的基因排序00:33I would have t

3、old you,its unlikely.我会告诉你,这不大可能00:39If you had asked whether or not we would actually be able torevive an extinct species,I would have said,pipe dream.如果你问我 我们能否让灭绝的物种复活 我会告诉你,呵呵00:42But Im actually standing here today,amazingly,to tell youthat not only is the sequencing of extinct genomes apossibi

4、lity,actually a modern-day reality,但我今天站在这里 想告诉你们,在当今现实中 不单有望排列出绝种生物的基因00:47amber:adj.琥珀色的;琥珀制的/n.琥珀;琥珀色/vt.使呈琥珀色 preserved:adj.保藏的;腌制的;喝醉的 morphologically:adv.词法地;形态学上地 phenomenal:adj.现象的;显著的;异常的;能知觉的;惊人的,非凡的 genome:n.基因组;染色体组revive:vi.复兴;复活;苏醒;恢复精神/vt.使复兴;使苏醒;回想起;重演,重播 pipe dream:白日梦,空想 sequencing

5、:n.计排序;计定序;排列程序/v.计定序(sequence的ing形式);使按顺序排列 genomes:n.遗基因组(genome复数)modern-day:adj.当代的;今日的but the revival of an extinct species is actually within reach,maybe not from the insects in amber-in fact,this mosquitowas actually used for the inspiration for Jurassic Park but from woolly mammoths,the well

6、 preserved remains ofwoolly mammoths in the permafrost.而且复活灭绝的生物也是可以办到的 或许不是琥珀中的昆虫 事实上这种蚊子 曾给侏罗纪公园灵感 但从猛犸象从永久冻土内保存完好的遗迹中可以看出00:56Woollies are a particularly interesting,quintessential imageof the Ice Age.猛犸象是冰川时期 精萃和有趣的代表01:11They were large.They were hairy.他们体型庞大,浑身毛茸茸01:16They had large tusks,and

7、we seem to have a very deepconnection with them,like we do with elephants.他们有硕大的獠牙,而且似乎人类和他们关系很密切 就像我们和大象的关系一样01:18Maybe its because elephants share many things in commonwith us.或许是因为大象 和我们有很多共同点01:22They bury their dead.They educate the next of kin.他们掩埋逝者,他们养育后代01:27They have social knits that are

8、very close.有着紧密的群体关系01:30revival:n.复兴;复活;苏醒;恢复精神;再生效 mosquito:n.蚊子 Jurassic:adj.侏罗系的;侏罗纪的/n.侏罗纪 woolly:adj.羊毛的;模糊的;似羊毛的/n.羊;毛织衣服 mammoths:n.长毛象;猛犸象;庞然大物/adj.巨大的,庞大的;猛犸似的 Woollies:adj.羊毛的;模糊的;似羊毛的/n.羊;毛织衣服 quintessential:adj.精髓的,精萃的 tusks:n.獠牙(tusk的复数);建墙面牙石/v.用长牙掘(tusk的第三人称单数)in common with:与一样 knit

9、s:n.针织品;皱痕(knit的复数)/v.纺编织;皱紧;接合(knit的第三人称单数)Or maybe its actually because were bound by deep time,because elephants,like us,share their origins in Africa someseven million years ago,and as habitats changed andenvironments changed,we actually,like the elephants,migrated out into Europe and Asia.又或许是因

10、为我们有着很长的历史 因为在几百万年前,和我们一样 大象的起源也是在非洲 随着栖息地和环境的改变 我们像大象一样迁徙 迁到欧洲和亚洲01:33So the first large mammoth that appears on the scene ismeridionalis,which was standing four meters tall weighingabout 10 tons,and was a woodland-adapted species所以世上的第一头猛犸象 是南方猛犸,有四米高 约十吨重,而且是能适应林地的物种01:50and spread from Western E

11、urope clear across Central Asia,across the Bering land bridge and into parts of NorthAmerica.然后从西欧跨过中亚 跨过白令陆桥 到达北美地区01:59TED演讲者：Hendrik Poina|Hendrik Poina演讲标题：Bring back the woolly mammoth!|寻回长毛猛犸！内容概要：It.s the dream of kids all around the world to see giant beasts walk the Earth again.Could and sh

12、ould that dream be realized?Hendrik Poinar talks about the next big thing:the quest to engineer a creature that looks very much like our furry friend,the woollymammoth.The first step,to sequence the woolly genome,is nearly complete.And it.s huge.世界上的孩子们都会梦想见到大型的生物在地球再次踏足。能否，也应不应该，让这个梦想实习？HendrikPoin

13、ar在这个大标题下给我们进行了科普：探索并造就一种看起来非常像我们毛茸茸的长毛猛犸的生物。第一步，排列长毛猛犸的基因，这基本完成了。这基因大得有点惊人。And then,again,as climate changed as it always does,andnew habitats opened up,we had the arrival of a steppe-adapted species called trogontherii in Central Asia pushingmeridionalis out into Western Europe.随后由于常见的气候变化 新的栖息地也随

14、之出现所以我们有了能在中亚适应草原的猛犸物种 叫草原猛犸 所以猛犸就从南方迁移到西欧02:07And the open grassland savannas of North America openedup,leading to the Columbian mammoth,a large,hairlessspecies in North America.广阔的北美热带稀树草原也成为新栖息地 在这里有了哥伦比亚猛犸 一种在北美的大型少毛猛犸02:19habitats:n.生态栖息地;(动植物的)经产地(habitat的复数形式)migrated:迁移/迁徙(migrate的过去式和过去分词)m

15、ammoth:n.长毛象;猛犸象;庞然大物/adj.巨大的,庞大的;猛犸似的 grassland:n.草原;牧草地 savannas:n.热带稀树草原(savanna的复数)hairless:adj.无毛的;秃顶的And it was really only about 500,000 years later that we hadthe arrival of the woolly,the one that we all know and love somuch,spreading from an East Beringian point of origin仅仅50万年后 一种猛犸出现了 就是

16、那种我们熟知并喜爱的 从东白令陆桥作为起点02:26across Central Asia,again pushing the trogontherii outthrough Central Europe,and over hundreds of thousands ofyears migrating back and forth across the Bering landbridge during times of glacial peaks and coming into directcontact with the Columbian relatives living in the s

17、outh,跨过中亚,将草原猛犸 推向中欧地区 再经过数百年的演变 在冰川时期 不断从白令陆桥来回往返 终于和栖息在南边的哥伦比亚种族 有了直接的联系02:37and there they survive over hundreds of thousands of yearsduring traumatic climatic shifts.并且他们在恶劣的气候变化下 存活了成千上万年02:53So theres a highly plastic animal dealing with greattransitions in temperature and environment,and doin

18、g very,very well.所以这是一种适应性极高的 能适应恶劣气候环境的动物02:58And there they survive on the mainland until about 10,000years ago,and actually,surprisingly,on the small islands offof Siberia and Alaska until about 3,000 years ago.直到一万年前,他们才从这个陆地上消失 事实上,很令人惊讶的是,在西伯利亚周边的一些小岛上 和在阿拉斯加那,他们3000年前才消失03:06migrating:v.迁移;迁徙

19、;移居(migrate的ing形式)back and forth:反复地,来回地 glacial:adj.冰的;冰冷的;冰河时代的peaks:n.山顶;峰巅(peak的复数)relatives:n.亲属;语关系词(relative的复数)traumatic:adj.外伤的;创伤的/n.外伤药climatic:adj.气候的;气候上的;由气候引起的;受气候影响的 transitions:n.过渡,转变(transition的复数形式);转场效果;转换滤镜 Siberia:n.西伯利亚So Egyptians are building pyramids and woollies are still

20、living on islands.所以埃及人在建造金字塔时 猛犸象还在岛上生活着03:15And then they disappear.之后他们才消失的03:20Like 99 percent of all the animals that have once lived,theygo extinct,likely due to a warming climate and fast-encroaching dense forests that are migrating north,像99%曾经存活过的动物一样 他们灭绝很可能是由于气候的暖化 和在北迁过程中 迅速生长起来的森林03:21a

21、nd also,as the late,great Paul Martin once put it,probablyPleistocene overkill,so the large game hunters that tookthem down.另外,正如已故的伟大保罗马丁曾经指出 很可能是“更新世时期”将他们赶尽杀绝 强大的猎人将他们都干掉了03:30Fortunately,we find millions of their remains strewn acrossthe permafrost buried deep in Siberia and Alaska,and wecan act

22、ually go up there and actually take them out.幸运的是,我们找到数以万计的遗骸 散布在斯伯利亚和阿拉斯加 深埋的永久冻土内,所以我们可以到那里 将它们取出来03:38And the preservation is,again,like those insects in amber,phenomenal.同样,对它们的保护也是完善的 就像那些琥珀中的昆虫一样03:48So you have teeth,bones with blood which look like blood,you have hair,and you have intact car

23、casses or heads whichstill have brains in them.所以你能看到牙齿,带血迹的骨头 看起来像血,你也能看到毛发 还能看到完整的尸体 或是仍有大脑在内的头部03:52So the preservation and the survival of DNA depends onmany factors,and I have to admit,most of which we stilldont quite understand,but depending upon when anorganism dies保护措施和DNA的存活将依靠很多方面因素 另外我不得不

24、承认 还有很大一部分仍旧是未解之谜 但依据生物死亡的时间04:02pyramids:n.(埃及)建金字塔(pyramid的复数);解剖锥体 overkill:vt.过度地杀伤/n.过度的杀伤威力 strewn:v.撒;散播(strew的过去分词)/adj.撒满的;散播的 preservation:n.保存,保留 carcasses:n.尸体;兽体(carcass的复数形式)and how quickly hes buried,the depth of that burial,theconstancy of the temperature of that burial environment,w

25、illultimately dictate how long DNA will survive overgeologically meaningful time frames.以及掩埋的速度和深度 还有掩埋环境温度的稳定性 我们可以从地质学角度的有效时间范围内 得出DNA还能存活多久04:11And its probably surprising to many of you sitting in thisroom that its not the time that matters,its not the length ofpreservation,its the consistency o

26、f the temperature of thatpreservation that matters most.对这里的大多数人来说,这可能有些不可思议 因为时间不是关键 保存时间的长度也不是关键 关键是保存温度的稳定性04:24So if we were to go deep now within the bones and the teeththat actually survived the fossilization process,the DNA所以如果我们真要去深究那些 经历了石化过程的骨头和牙齿 那么那些曾经完整,被组蛋白紧裹的DNA 将无疑暴露在细菌的威胁中04:34that

27、actually survived the fossilization process,the DNAwhich was once intact,tightly wrapped around histoneproteins,is now under attackDNA 将无疑暴露在细菌的威胁中04:34by the bacteria that lived symbiotically with the mammothfor years during its lifetime.这些细菌也是当初与猛犸象在世时 共生的细菌04:46因此那些细菌,和其他环境细菌 游离水和氧气,其实会将DNA分解 分解成

28、更小的DNA片段 这些片段分布不均 小的才有10对碱基对,最好的情况下 也只有几百对碱基对04:50So most fossils out there in the fossil record are actuallycompletely devoid of all organic signatures.所以化石记录那里大部分的化石 其实都是完全无有机特征的05:07burial:n.埋葬;葬礼;弃绝/adj.埋葬的 constancy:n.坚定不移;恒久不变 consistency:n.计一致性;稠度;相容性fossilization:n.石化;僵化 tightly:adv.紧紧地;坚固地

29、wrapped:adj.有包装的/v.包裹;覆盖(wrap的过去分词)proteins:n.生化蛋白质(protein复数)bacteria:n.微细菌 symbiotically:adv.symbiotic的变形 adj.生物学共生的亦作symbiotical fossils:n.古生化石(fossil复数形式)devoid:adj.缺乏的;全无的 signatures:n.签名;鲜明特征(signature的复数)But a few of them actually have DNA fragments that survivefor thousands,even a few millio

30、ns of years in time.只有很少的一部分 有存活数千年的有DNA片段 有的甚至有几百万年历史05:12And using state-of-the-art clean room technology,wevedevised ways that we can actually pull these DNAs awayfrom all the rest of the gunk in there,and its not surprisingto any of you sitting in the room that if I take a mammothbone or a tooth

31、 and I extract its DNA that Ill get mammothDNA,利用最先进的净化室技术 我们设计了不同方案从这些粘泥状物体中 提取出这些DNA 如果我拿出一根猛犸骨或一颗牙齿 然后提取它的DNA,我将得到猛犸的DNA 这对大家来说,不足为奇05:20but Ill also get all the bacteria that once lived with themammoth,and,more complicated,Ill get all the DNA thatsurvived in that environment with it,so the bacte

32、ria,thefungi,and so on and so forth.但我同时也得到了与猛犸同时期的细菌 应该说,我提取到了 生存在那个时期的所有DNA 还有细菌,真菌,还有杂七杂八的05:35Not surprising then again that a mammoth preserved in thepermafrost will have something on the order of 50 percent ofits DNA being mammoth,whereas something like theColumbian mammoth,另一件不足为奇的事是 保存在冻土里的猛

33、犸 会有约50%的是属于自己的DNA 而像哥伦比亚猛犸05:46living in a temperature and buried in a temperateenvironment over its laying-in will only have 3 to 10 percentendogenous.生活在一种温度下,掩埋在自己温和的墓地里 却只有3%到10%属于自己的DNA05:55state-of-the-art:adj.最先进的;已经发展的;达到最高水准的 devised:v.设计(devise的过去式和过去分词);计划;发明 gunk:n.泥状物质;黏性物质;无特殊形状之一堆 ex

34、tract:vt.提取;取出;摘录;榨取/n.汁;摘录;榨出物;选粹 fungi:n.真菌;菌类;蘑菇(fungus的复数)temperate:adj.温和的;适度的;有节制的 endogenous:adj.生物内生的;内因性的But weve come up with very clever ways that we can actuallydiscriminate,capture and discriminate,the mammoth fromthe non-mammoth DNA,and with the advances in high-throughput sequencing,w

35、e can actually pull out andbioinformatically re-jig all these small mammoth fragmentsand place them onto a backbone of an Asian or Africanelephant chromosome.然而我们想出了巧妙的方法 我们其实能够区别,捕捉区别 哪些是猛犸的DNA 加上高通量测序的帮助我们能够提取出 并从生物信息角度重新加工这些小DNA片段 然后植入亚洲象或非洲象 的染色体主链上06:02And so by doing that,we can actually get a

36、ll the little pointsthat discriminate between a mammoth and an Asianelephant,and what do we know,then,about a mammoth?这样做,我们就能得到这些小点 来区别猛犸和亚洲象 那么,我们能从猛犸身上了解到什么呢？06:23Well,the mammoth genome is almost at full completion,and we know that its actually really big.Its mammoth.其实,猛犸的基因组基本是排满的 它确实很大,毕竟是猛犸嘛

37、06:31So a hominid genome is about three billion base pairs,butan elephant and mammoth genome is about two billion basepairs larger,and most of that is composed of small,repetitive DNAs that make it very difficult to actually re-jigthe entire structure of the genome.原始人的基因大概有30亿对碱基对 但是大象和猛犸的基因 约多出20亿

38、对碱基对 大部分是由小而重复的DNA组成的 这使得重组整个基因组变得十分困难06:38come up with:提出;想出;赶上 discriminate:vt.歧视;区别;辨别/vi.区别;辨别 pull out:离开,撤离;拔出;渡过难关;恢复健康;折叠的大张插页;飞机进场重新飞起 backbone:n.支柱;主干网;决心,毅力;脊椎 chromosome:n.遗细胞染料染色体(形容词chromosomal,副词chromosomally)completion:n.完成,结束;实现 hominid:n.原始人类;人科动物/adj.人类及其祖先的composed:adj.镇静的;沉着的/v.

39、组成;作曲(compose的过去分词);著作 repetitive:adj.重复的www.XiYuS锡育软件So having this information allows us to answer one of theinteresting relationship questions between mammoths andtheir living relatives,the African and the Asian elephant,所以拥有这些信息,我们就能够 解答那有趣的种族问题 包括猛犸之间,和它们如今在世的近亲 那些非洲象亚洲象06:52all of which shared

40、 an ancestor seven million years ago,but所有那些七百万年前都是一家人的象 但是猛犸的基因显示 它和亚洲象有着最近的共同祖先 约在六all of which shared an ancestor seven million years ago,butthe genome of the mammoth shows it to share a most recentcommon ancestor with Asian elephants about six millionyears ago,so slightly closer to the Asian ele

41、phant.基因显示 它和亚洲象有着最近的共同祖先 约在六百万年前 所以多少和亚洲象比较亲近07:01With advances in ancient DNA technology,we can actuallynow start to begin to sequence the genomes of those otherextinct mammoth forms that I mentioned,and I just wantedto talk about two of them,the woolly and the Columbianmammoth,both of which were

42、living very close to each otherduring glacial peaks,在研究古代DNA技术的帮助下 我们现在已经能开始重组 其他灭绝了的猛犸物种的基因 我在这里就提两种 长毛猛犸和哥伦比亚猛犸 在冰川时期 两种生活得非常近07:13so when the glaciers were massive in North America,thewoollies were pushed into these subglacial ecotones,andcame into contact with the relatives living to the south,a

43、ndthere they shared refugia,and a little bit more than therefugia,it turns out.当北美的冰川还是很庞大的时候 长毛猛犸就被推进冰川下的过渡带 来到南边,接触到了其他种族 他们一同避难 慢慢地,就不止避难了07:30It looks like they were interbreeding.似乎他们还相互交配繁殖07:42glaciers:n.地理水文冰川(glacier的复数);地理水文冰河 refugia:n.生残遗种保护区;冰期生物种遗区(单数形式refugium)interbreeding:n.遗杂种繁殖;异血

44、缘交配/v.异种交配;使混种(interbreed的现在分词)And that this is not an uncommon feature in Proboscideans,because it turns out that large savanna male elephants willoutcompete the smaller forest elephants for their females.这在长鼻类动物中不是新鲜事 因为发现 大型的热带草原公象 比稍小的森林象更会求偶07:45So large,hairless Columbians outcompeting the sma

45、ller malewoollies.所以硕大的,无毛的哥伦比亚猛犸 完胜稍小的公长毛猛犸07:54It reminds me a bit of high school,unfortunately.这让我不禁想起高中的时候07:59(Laughter)So this is not trivial,given the idea that we want torevive extinct species,because it turns out that an Africanand an Asian elephant can actually interbreed and have liveyoun

46、g,（笑声）这其实很重要 因为我们要复活灭绝的种类 因为我们发现非洲象和亚洲象 是能够杂交产生后代的08:01and this has actually occurred by accident in a zoo inChester,U.K.,in 1978.这在1978年的英国切斯特的一座公园里 是有发生过的08:12So that means that we can actually take Asian elephantchromosomes,modify them into all those positions weveactually now been able to discri

47、minate with the mammothgenome,we can put that into an enucleated cell,differentiate that into a stem cell,这就意味着我们能把亚洲象的染色体 嵌入到我们目前能够与猛犸基因区别开来 的所有基因位置 我们可以将它放入一个无核的细胞中 分化为一个干细胞08:18uncommon:adj.不寻常的；罕有的/adv.非常地 savanna:n.生态热带草原;热带的稀树大草原 interbreed:vt.异种交配;混种;使品种间杂交/vi.异种交配;混种;杂种繁殖 Chester:n.切斯特(美国港口城

48、市);切斯特(英国一城市)chromosomes:n.遗细胞染料染色体(chromosome的复数形式)differentiate:vi.区分,区别/vt.区分,区别 stem cell:干细胞subsequently differentiate that maybe into a sperm,artificially inseminate an Asian elephant egg,and over along and arduous procedure,actually bring back somethingthat looks like this.然后或许再分化为一个精子 人工授精到亚

49、洲象的卵子里 在经过一个漫长艰苦的过程 我们弄出了这么一个东西08:30Now,this wouldnt be an exact replica,because the shortDNA fragments that I told you about will prevent us frombuilding the exact structure,but it would make somethingthat looked and felt very much like a woolly mammoth did.确切来说,这不是一个精确复制品 因为我提到的短DNA片段 会妨碍我们构建真实的结构

50、 但我们还是做出来看起来感觉起来 都很像长毛猛犸的生物08:42Now,when I bring up this with my friends,we often talkabout,well,where would you put it?当我把这个给朋友看的时候 我们经常会谈到,不错,但你能把它放在哪啊？08:53Where are you going to house a mammoth?你打算把它关在哪里啊？08:58Theres no climates or habitats suitable.我们没有合适的气候和住所啊09:00Well,thats not actually the