查爾斯·達(dá)爾文生于1809年2月12日。200年后，他在我的祖國(guó)英國(guó)成了民族英雄。全世界各地都在以各種形式紀(jì)念他的200年誕辰，比如，電視、廣播、圖書(shū)、博物館展覽、研討會(huì)，以及各種各樣的活動(dòng)。今年也正值達(dá)爾文的著作《物種起源》——這本備受爭(zhēng)議的書(shū)——出版150年。

在達(dá)爾文誕辰100周年時(shí)，對(duì)他的紀(jì)念活動(dòng)并不多。1959年，我給自己的一群中學(xué)學(xué)生作了一個(gè)關(guān)于達(dá)爾文的報(bào)告，他們相聚只是來(lái)討論文化與文學(xué)。第二年，我去劍橋大學(xué)讀書(shū)，在劍橋大學(xué)基督學(xué)院的餐廳里掛著達(dá)爾文的畫(huà)像，因?yàn)閷W(xué)生時(shí)代的他也在劍橋?qū)W習(xí)和生活過(guò)。我的第一份工作是在倫敦大學(xué)學(xué)院做一名講師，上午茶歇的時(shí)候，我經(jīng)常和一位來(lái)自生物系的達(dá)爾文專(zhuān)家Richard Freeman聊天，所以我的一生都對(duì)達(dá)爾文和他的著作非常熟悉。

達(dá)爾文間接地為我開(kāi)啟了我作為地質(zhì)學(xué)家的事業(yè)?！段锓N起源》一書(shū)的整個(gè)第10章都用來(lái)介紹他對(duì)自己理論的科學(xué)反證，其中最有力的是“寒武紀(jì)生命大爆炸”。在形成于5億3500萬(wàn)年前的寒武紀(jì)的巖石中，突然發(fā)現(xiàn)了大量古生物的化石，這段時(shí)期對(duì)于地球整個(gè)45億6000萬(wàn)年的歷史而言?xún)H僅是短暫的一頁(yè)。1859年，當(dāng)達(dá)爾文寫(xiě)《物種起源》的第一版時(shí)，人類(lèi)還不能準(zhǔn)確地判斷巖石的年代，而且寒武紀(jì)這個(gè)名稱(chēng)也沒(méi)有被使用。他曾經(jīng)的導(dǎo)師Adam Sedgwick推薦以此命名志留紀(jì)早期的古巖石，達(dá)爾文隨后采用了這個(gè)名字。

達(dá)爾文寫(xiě)道：“如果進(jìn)化論的理論是正確的，在寒武紀(jì)地層沉淀之前，應(yīng)該存在一個(gè)很久的時(shí)代，這是無(wú)可爭(zhēng)論的，這段時(shí)期可能與從寒武紀(jì)到現(xiàn)在的時(shí)間一樣長(zhǎng)，甚至還要久。而且，在這段時(shí)期地球上物種繁多。對(duì)于為什么我們沒(méi)有發(fā)現(xiàn)大量的屬于這個(gè)比寒武紀(jì)還要早的時(shí)期的化石，我無(wú)法給出滿意的答案。以R. Murchison爵士為首的一些杰出的地質(zhì)學(xué)家，直到最近才證實(shí)，志留紀(jì)最底層的有機(jī)物遺留是生命的第一道曙光?！边_(dá)爾文認(rèn)為，也許未來(lái)在早于寒武紀(jì)或前寒武紀(jì)的地層中發(fā)現(xiàn)化石，才能回答這個(gè)問(wèn)題。當(dāng)時(shí)，地質(zhì)學(xué)家只調(diào)查研究了地球上的很少的一部分巖石，比如當(dāng)時(shí)中國(guó)的地質(zhì)幾乎絲毫不為人們所了解。他注釋道，加拿大在前寒武紀(jì)地層中發(fā)現(xiàn)了一塊可能是化石的沉積物。

自《物種起源》發(fā)表一個(gè)世紀(jì)過(guò)去了，地質(zhì)學(xué)家研究了地球上越來(lái)越多的地層，化石生物的每一次新發(fā)現(xiàn)都出現(xiàn)在寒武紀(jì)的初期。似乎達(dá)爾文錯(cuò)了。

1957年的一天，下午放學(xué)后，我和兩個(gè)同學(xué)從英國(guó)中部小城萊斯特騎車(chē)去附近的charnwood森林山區(qū)。我們帶著繩子去一個(gè)廢棄的采石場(chǎng)玩攀巖。我爬到一個(gè)小懸崖的頂上，把繩子放下去，我的朋友在下面等著。其中一個(gè)人注意到一塊石頭上有葉子形狀的印記，就讓我下來(lái)看看，因?yàn)槲覍?duì)地質(zhì)學(xué)感興趣。我的老師告訴我這些巖石是前寒武紀(jì)的，因此不應(yīng)該還含有化石，因此我告訴了我的父親，他邀請(qǐng)他的一位朋友來(lái)幫忙看看。他就是Trevor Ford，萊斯特大學(xué)的地質(zhì)學(xué)老師。我們穿過(guò)樹(shù)林看到了巖石，他說(shuō)，“我的上帝，這是一塊化石！”

幾周后，他把發(fā)現(xiàn)告訴了地質(zhì)系的主任，并為當(dāng)?shù)匾槐居?guó)地理學(xué)雜志寫(xiě)了一篇科學(xué)文章，且于1958年發(fā)表，他為這種化石命名為Charnia masoni。Ford博士帶領(lǐng)英國(guó)地質(zhì)調(diào)查隊(duì)考察了這塊化石，發(fā)現(xiàn)前寒武紀(jì)化石的新聞迅速傳遍全球。這在地球另一端的南澳大利亞阿德萊德市也引起了轟動(dòng)，因?yàn)?年前，阿德萊德大學(xué)的研究生Reginald Sprigg就告訴過(guò)他的導(dǎo)師，自己在弗林德斯山一個(gè)叫埃迪卡拉的地方發(fā)現(xiàn)了前寒武紀(jì)化石。Sprigg聲稱(chēng)發(fā)現(xiàn)了比寒武紀(jì)更早的化石，但他的導(dǎo)師將信將疑，認(rèn)為那些巖石是寒武紀(jì)而非前寒武紀(jì)。Ford博士文章中的圖片顯示Charnia與一塊Sprigg發(fā)現(xiàn)的化石很像。澳大利亞地質(zhì)學(xué)家都匆匆趕去埃迪卡拉，并帶回很多化石來(lái)研究。著名的科學(xué)雜志《自然》在1958年刊登了對(duì)澳大利亞化石的介紹，埃迪卡拉現(xiàn)在成為聯(lián)合國(guó)教科文組織世界遺產(chǎn)，前寒武紀(jì)化石也以埃迪卡拉生物的名字被全世界所熟知。除了南極洲，每一個(gè)大陸都發(fā)現(xiàn)了前寒武紀(jì)化石，包括中國(guó)的長(zhǎng)江三峽。地理學(xué)家確信，在寒武紀(jì)之前存在一個(gè)埃迪卡拉紀(jì)，在距今6億3000萬(wàn)-5億4200萬(wàn)年前。“在這段漫長(zhǎng)的時(shí)期內(nèi)，世界上物種繁多?！碑?dāng)達(dá)爾文寫(xiě)下這句的時(shí)候，他是正確的。我開(kāi)始了自己作為地質(zhì)學(xué)家這一生的事業(yè)。

Charles Darwin (1809-1882) was born on 12 February 1809 and 200 years after his birth he is a national hero in my country， the United Kingdom of Great Britain Northern Ireland. His anniversary is being celebrated all over the world with TV and radio programmes， books， museum exhibitions， meetings and many other activities. This year is also the 150th anniversary of the publication of his controversial book， The Origin of Species.

Celebrations were less extensive at Darwin's 100th anniversary but in 1959 I gave a talk about him to a club of my fellow middle school students that met to discuss culture and literature. I went to Cambridge University in the following year where Darwin's portrait hung in our dining hall at Christ's College because he had lived and studied there when he was a student. When I got my first job as a lecturer at University College London I regularly chatted to Dr Richard Freeman， a Darwin expert in the Biology Department， over coffee at our morning break. So I have been familiar with Darwin and his work almost all my life.

Darwin also indirectly launched me on my career as a geologist. He devoted the whole of Chapter 10 of The Origin of Species to scientific objections to his theory， and one of the most serious was the \"Cambrian explosion\". Fossilized remains of ancient life-forms suddenly become abundant in sedimentary rocks that formed in the Cambrian period about 535 million years ago， only a fraction of the Earth's total life-time of 4，560 million years. Absolute ages of rocks could not be measured when Darwin wrote the first edition in 1859 and the name Cambrian had not yet been introduced. He used it later after his former professor， Adam Sedgwick， proposed the name for ancient rocks previously included in the younger Silurian period.

Darwin wrote: \"... if the theory [of evolution] be true， it is indisputable that before the lowest Cambrian stratum was deposited long periods elapsed， as long as， or probably far longer than， the whole interval from the Cambrian age to the present day; and that during these vast periods the world swarmed with living creatures. To the question why we do not find rich fossiliferous deposits belonging to these assumed earliest periods prior to the Cambrian system， I can give no satisfactory answer. Several eminent geologists， with Sir R. Murchison at their head， were until recently convinced that we beheld in the organic remains of the lowest Silurian stratum the first dawn of life.\"Darwin argued that the question might be answered in future by the discovery of fossils in rocks that formed before the Cambrian period， in Precambrian times. Very few of the Earth's rocks had been investigated by geologists， for example almost nothing was known about Chinese geology. He noted that a possible fossil had been discovered in Precambrian rocks in Canada.

For almost a century， geologists studied more and more parts of the world and everywhere the first traces of fossilized creatures continued to crop up at the beginning of the Cambrian period. It looked as though Darwin was wrong.

Then one afternoon after school in 1957 I rode by bicycle with two classmates from Leicester， a small city in the middle of England， to a nearby hilly district called Charnwood Forest. We took a rope to go rock-climbing up the side of a disused stone quarry. I walked to the top of a small cliff to lower our rope while my friends waited below. One of them noticed a leaf-like impression in the rock and called to me to come down and take a look because I was interested in geology. My teachers had told me that the rocks were Precambrian and therefore should not contain fossils， so I told my father about it and he invited one of his friends to come and have a look. He was Dr Trevor Ford， a geology teacher at Leicester University. We walked through the trees to the rocks， and Dr Ford said， \"My God， it is [a fossil]!\"

In the next few weeks he told the head of the Geology Department about the discovery and wrote a scientific paper for a local British geological journal which was published in 1958 and named the fossil Charnia masoni. Dr Ford took the Director of the British Geological Survey to see it and news of a Precambrian fossil quickly spread round the world. It caused a stir in the city of Adelaide at the other side of the world in South Australia because nine years earlier Reginald Sprigg， a graduate of Adelaide University， had told his professors that he had found Precambrian fossils at a place called Ediacara in the Flinders Mountains. Sprigg had claimed to find ancient fossils before and his professors took his claims with a large pinch of salt， thinking that the rocks were Cambrian not Precambrian. The photograph of Charnia in Ford's paper was like one of Sprigg's fossils. The Austrilian geologists hurried to Ediacara in a lorry and brought back many fossils to study. The famous scientific journal Nature published an account of the Australian fossils in 1958 and Ediacara is now a UNESCO World Heritage geology site and the Precambrian fossils are known everywhere as the Ediacara biota. They have been found in every continent except Antarctica， including the Three Gorges of the Yangtze River in China. Geologists now recognize an Ediacaran Period at 630 to 542 million years ago， before the Cambrian Period. Darwin was right when he wrote， 揹uring these vast periods the world swarmed with living creatures.?I was launched on a lifetime as a geologist.