0:00:02 > 0:00:05Our Earth is the only known planet that sustains life,
0:00:05 > 0:00:08and it does so in abundance.
0:00:21 > 0:00:25I have been fortunate enough, over the years,
0:00:25 > 0:00:29to travel to some of the most extraordinary and remote places on Earth
0:00:29 > 0:00:32to find and film animals.
0:00:32 > 0:00:35This is the biggest flower in the world.
0:00:35 > 0:00:37The blue whale!
0:00:37 > 0:00:41It's the biggest creature that exists on the planet.
0:00:43 > 0:00:48The sheer number and variety of animals and plants is astonishing.
0:00:48 > 0:00:54Estimates of the number of different species vary from six million to 100 million.
0:00:54 > 0:00:59Nobody knows how many different kinds of animals there are here.
0:00:59 > 0:01:02Wherever you look, there's life.
0:01:02 > 0:01:05There are often a multitude of variations on a single pattern -
0:01:05 > 0:01:10nearly 200 different kinds of monkeys, for example.
0:01:11 > 0:01:15And 315 hummingbirds.
0:01:16 > 0:01:19Nearly a thousand bats.
0:01:26 > 0:01:32And beetles... at least 350,000 species of them.
0:01:34 > 0:01:38Not to mention a quarter of a million different kinds of flowering plants.
0:01:45 > 0:01:48The variety is astounding.
0:01:48 > 0:01:50HE CHUCKLES
0:01:54 > 0:01:58Even in this one small English woodland,
0:01:58 > 0:02:03you might see four or five different kinds of finches.
0:02:07 > 0:02:12Why should there be such a dazzling variety?
0:02:12 > 0:02:17And how can we make sense of such a huge range of living organisms?
0:02:18 > 0:02:20200 years ago,
0:02:20 > 0:02:26a man was born who was to explain this astonishing diversity of life.
0:02:26 > 0:02:31In doing so, he revolutionised the way in which we see the world
0:02:31 > 0:02:33and our place in it.
0:02:33 > 0:02:36His name was Charles Darwin.
0:02:57 > 0:02:59This book, the Holy Bible,
0:02:59 > 0:03:05explains how this wonderful diversity came about.
0:03:05 > 0:03:11On the third day after the creation of the world, God created plants.
0:03:11 > 0:03:15On the fifth day, fish and birds,
0:03:15 > 0:03:18and then on the sixth day, mammals,
0:03:18 > 0:03:21and finally, man.
0:03:21 > 0:03:25That explanation was believed, literally,
0:03:25 > 0:03:31by pretty well the whole of Western Europe for the best part of 2,000 years,
0:03:31 > 0:03:36and generations of painters pictured it for the faithful.
0:03:39 > 0:03:43This version was painted in Italy in the 16th century.
0:03:43 > 0:03:46Here is God in the Garden of Eden,
0:03:46 > 0:03:49which is now filled with all kinds of animals.
0:03:49 > 0:03:54Here he is pulling Adam out of the Earth.
0:03:54 > 0:04:00And here, creating the first woman by putting Adam to sleep,
0:04:00 > 0:04:05and then taking one of his ribs and extracting Eve from his side.
0:04:08 > 0:04:12She comes out, assisted by two angels.
0:04:12 > 0:04:18And when God had finished, he said to Adam and Eve,
0:04:18 > 0:04:23"Be fruitful and multiply and replenish the earth and subdue it,
0:04:23 > 0:04:27"and have dominion over the fish of the sea and over the fowl of the air,
0:04:27 > 0:04:32"and over every living thing that moveth upon the Earth."
0:04:34 > 0:04:36That made it clear that, according to the Bible,
0:04:36 > 0:04:41humanity could exploit the natural world as they wished.
0:04:46 > 0:04:51This view of mankind's superiority still stood when, in 1831,
0:04:51 > 0:04:56a British surveying ship, the Beagle, set off on a voyage around the world.
0:04:56 > 0:04:59On board, as a companion to the captain,
0:04:59 > 0:05:02was the 22-year-old Charles Darwin.
0:05:04 > 0:05:09They crossed the Atlantic and made landfall on the coast of Brazil.
0:05:12 > 0:05:17There, the sheer abundance of tropical nature astonishes the newcomer,
0:05:17 > 0:05:21as I discovered when I retraced Darwin's steps 30 years ago
0:05:21 > 0:05:25for a television series about the diversity of nature.
0:05:26 > 0:05:30Darwin, as a boy, had been a fanatical collector of insects,
0:05:30 > 0:05:34and here he was enthralled, almost to the point of ecstasy.
0:05:34 > 0:05:37In one day, in a small area,
0:05:37 > 0:05:42he discovered 69 different species of beetle.
0:05:42 > 0:05:44As he wrote in his journal,
0:05:44 > 0:05:49"It's enough to disturb the composure of the entomologist's mind
0:05:49 > 0:05:53"to contemplate the future dimension of a complete catalogue."
0:05:56 > 0:06:01They went south, rounded Cape Horn and so reached the Pacific.
0:06:04 > 0:06:08And then, in September 1835,
0:06:08 > 0:06:12after they had been away for almost four years,
0:06:12 > 0:06:16they landed on the little-known islands of the Galapagos.
0:06:16 > 0:06:20Here they found creatures that existed nowhere else in the world.
0:06:20 > 0:06:23Cormorants that had lost the power of flight.
0:06:25 > 0:06:28Lizards that swam out through the surf
0:06:28 > 0:06:30to graze on the bottom of the sea.
0:06:33 > 0:06:38Darwin, who had studied botany and geology at Cambridge University,
0:06:38 > 0:06:41collected specimens of the animals and plants,
0:06:41 > 0:06:44and as usual, when he went ashore to investigate,
0:06:44 > 0:06:47described what he found in his journal.
0:06:49 > 0:06:55"My servant and self were landed a few miles to the northeast,
0:06:55 > 0:07:00"in order that I might examine the district mentioned above
0:07:00 > 0:07:03"as resembling chimneys."
0:07:03 > 0:07:06Volcanic chimneys, presumably.
0:07:06 > 0:07:09"The comparison would have been more exact
0:07:09 > 0:07:13"if I had said, 'the iron furnaces near Wolverhampton.' "
0:07:13 > 0:07:15HE CHUCKLES
0:07:21 > 0:07:23The British resident in the Galapagos
0:07:23 > 0:07:27claimed that he knew from the shape of a giant tortoise's shell,
0:07:27 > 0:07:29which island it had come from.
0:07:29 > 0:07:32If it had a rounded front,
0:07:32 > 0:07:38it came from a well-watered island, where it fed on lush ground plants.
0:07:38 > 0:07:41Whereas one from a drier island had a peak at the front,
0:07:41 > 0:07:46which enabled it to reach up to higher vegetation.
0:07:49 > 0:07:55Were these tortoises, each on their separate islands, different species?
0:07:55 > 0:08:00And if so, was each one a separate act of divine creation?
0:08:02 > 0:08:06The differences that Darwin had noticed
0:08:06 > 0:08:10amongst these Galapagos animals were, of course, all tiny,
0:08:10 > 0:08:12but if they could develop,
0:08:12 > 0:08:16wasn't it possible that over the thousands or millions of years
0:08:16 > 0:08:19a whole series of such differences might add up
0:08:19 > 0:08:21to one revolutionary change?
0:08:23 > 0:08:29On his voyage home, Darwin had time to ponder on these things.
0:08:29 > 0:08:36Could it be that species were not fixed for all time, but could, in fact, slowly change?
0:08:41 > 0:08:46On his return, he sorted out his specimens and sent them off
0:08:46 > 0:08:51to relevant experts so that each could be identified and classified.
0:08:55 > 0:09:01Most of the mammal bones and fossils he sent to Richard Owen.
0:09:01 > 0:09:05Owen was one of the most brilliant zoologists of his time.
0:09:05 > 0:09:08He was the first to recognise dinosaurs,
0:09:08 > 0:09:11and indeed had invented their very name,
0:09:11 > 0:09:17and he would later become the creator and first director of the Natural History Museum in London.
0:09:22 > 0:09:27Many of the specimens that Darwin collected are still preserved and treasured
0:09:27 > 0:09:33here among the 70 million other specimens housed in the museum that Owen founded.
0:09:38 > 0:09:41And here is one of them.
0:09:42 > 0:09:47It's obviously the lower jaw of some great animal, and when Darwin discovered it,
0:09:47 > 0:09:50it had bits of skin and hair attached to it,
0:09:50 > 0:09:55so that at first it was thought to be the remains of some unknown living species.
0:09:55 > 0:10:03But now we know that it is a species that was extinct for some 10,000 years, a giant ground sloth.
0:10:03 > 0:10:06Owen examined it in great detail
0:10:06 > 0:10:12and eventually described it and gave it the name of Mylodon darwinii,
0:10:12 > 0:10:15in honour of its discoverer.
0:10:15 > 0:10:22But that mutual respect between two great men of science was not to last.
0:10:26 > 0:10:33Soon after his return from his voyage, Darwin made his home here, in Down House, in Kent.
0:10:33 > 0:10:35Here he wrote an account of his travels
0:10:35 > 0:10:40and worked on detailed scientific treatises about corals
0:10:40 > 0:10:44and barnacles and the geology and fossils of South America.
0:10:46 > 0:10:53But he also pondered deeply on what he had seen in the Galapagos and elsewhere.
0:10:53 > 0:10:56Maybe species were not fixed.
0:11:16 > 0:11:20Every day, he took a walk in this small spinney
0:11:20 > 0:11:23that he had planted at the end of his garden.
0:11:24 > 0:11:29And it was here that he came to ponder on the problems of natural history,
0:11:29 > 0:11:32including that mystery of mysteries -
0:11:32 > 0:11:36how could one species turn into another.
0:11:38 > 0:11:41He noted that most, if not all, animals
0:11:41 > 0:11:46produce many more young than live to breed themselves.
0:11:46 > 0:11:52This female blue tit, for example, may well lay a dozen eggs a year -
0:11:52 > 0:11:54perhaps 50 or so in her lifetime.
0:11:54 > 0:11:58Yet only two of her chicks need to survive and breed themselves
0:11:58 > 0:12:01to maintain the numbers of the blue tit population.
0:12:01 > 0:12:06Those survivors, of course, are likely to be the healthiest
0:12:06 > 0:12:09and best suited to their particular environment.
0:12:09 > 0:12:11Their characteristics are then inherited.
0:12:11 > 0:12:14So perhaps, over many generations,
0:12:14 > 0:12:20and particularly if there are environmental changes, species may well change.
0:12:20 > 0:12:26Only the fittest survive, and that was the key.
0:12:26 > 0:12:30He called the process "natural selection".
0:12:37 > 0:12:43That would explain the differences that he had noted in the finches
0:12:43 > 0:12:46that he had brought back from the Galapagos.
0:12:46 > 0:12:50They were very similar, except for their beaks.
0:12:50 > 0:12:55This one has a very thin, delicate beak which it uses to catch insects.
0:12:56 > 0:12:58This one, on the other hand,
0:12:58 > 0:13:02which came from an environment where there were a lot of nuts,
0:13:02 > 0:13:07has a big, heavy beak which enables it to crack them.
0:13:07 > 0:13:09So maybe,
0:13:09 > 0:13:11over the vastness of geological time,
0:13:11 > 0:13:15and particularly if species were invading new environments,
0:13:15 > 0:13:21those changes would amount to very radical changes indeed.
0:13:32 > 0:13:37Darwin drew a sketch in one of his notebooks to illustrate his idea,
0:13:37 > 0:13:44showing how a single ancestral species might give rise to several different ones,
0:13:44 > 0:13:49and then wrote above it a tentative "I think".
0:13:57 > 0:14:00Now he had to prove his theory,
0:14:00 > 0:14:06and he spent years gathering abundant and convincing evidence.
0:14:06 > 0:14:09He was an extraordinary letter writer.
0:14:09 > 0:14:14He wrote as many as a dozen letters a day to scientists and naturalists all over the world.
0:14:26 > 0:14:28He also realised,
0:14:28 > 0:14:31that when people had first started domesticating animals,
0:14:31 > 0:14:36they had been doing experiments for him - for centuries.
0:14:40 > 0:14:46All domestic dogs are descended from a single ancestral species - the wolf.
0:14:46 > 0:14:51Dog breeders select those pups that have the characteristics that happen to please them.
0:14:51 > 0:14:57Nature, of course, selects those young animals that are best suited to a particular environment,
0:14:57 > 0:15:01but the process is essentially the same,
0:15:01 > 0:15:05and in both cases it has produced astonishing variety.
0:15:12 > 0:15:16In effect, many of these different breeds
0:15:16 > 0:15:21could be considered different species because they do not, indeed they cannot, inter-breed.
0:15:21 > 0:15:27For purely mechanical reasons, there's no way in which a Pekingese can mate with a Great Dane.
0:15:34 > 0:15:38Of course, it's true that if you used artificial insemination,
0:15:38 > 0:15:41you could get crosses between almost any of these breeds,
0:15:41 > 0:15:45but that's because human beings have been selecting between dogs
0:15:45 > 0:15:48for only a few centuries.
0:15:48 > 0:15:53Nature has been selecting between animals for millions of years -
0:15:53 > 0:15:56tens of millions, even hundreds of millions of years,
0:15:56 > 0:16:00so what might have started out as we would consider to be breeds
0:16:00 > 0:16:04have now become so different they are species.
0:16:25 > 0:16:31Darwin, sitting in Down House, wrote to pigeon fanciers and rabbit breeders,
0:16:31 > 0:16:36asking all kinds of detailed questions about their methods and results.
0:16:36 > 0:16:40He himself, being a country gentleman and running an estate,
0:16:40 > 0:16:43knew about breeding horses and sheep and cattle.
0:16:43 > 0:16:48And he also conducted careful experiments with plants in his greenhouse.
0:16:53 > 0:16:59But Darwin knew that the idea that species could appear without divine intervention
0:16:59 > 0:17:01would appal society in general,
0:17:01 > 0:17:05and it was also contrary to the beliefs of his wife, Emma,
0:17:05 > 0:17:08who was a devout Christian.
0:17:08 > 0:17:13Perhaps for that reason, he was keen to keep the focus of his work scientific.
0:17:15 > 0:17:19He made a point of not being drawn in public about his religious beliefs,
0:17:19 > 0:17:25but in the latter part of his life, he withdrew from attending church.
0:17:25 > 0:17:30On Sundays, he would escort Emma and the children here to the parish church in Down,
0:17:30 > 0:17:33but while they went into the service,
0:17:33 > 0:17:38he remained outside and went for a walk in the country lanes.
0:17:45 > 0:17:50Perhaps because he feared that his theory would cause outrage in some quarters,
0:17:50 > 0:17:55he delayed publishing it year after year after year.
0:17:55 > 0:17:58But he wrote a long abstract of it,
0:17:58 > 0:18:04and then on July 5th 1844, he wrote this letter to his wife.
0:18:04 > 0:18:05"My dear Emma.
0:18:05 > 0:18:09"I have just finished this sketch of my species theory..."
0:18:09 > 0:18:13Some sketch - it was 240 pages long.
0:18:13 > 0:18:17"I therefore write this in case of my sudden death,
0:18:17 > 0:18:21"that you will devote £400 to its publication."
0:18:21 > 0:18:25He then goes on to list his various naturalist friends
0:18:25 > 0:18:29who would be asked to edit it and check it,
0:18:29 > 0:18:31and he ends the letter charmingly,
0:18:31 > 0:18:33"My dear wife...
0:18:33 > 0:18:37"yours affectionately, CR Darwin."
0:18:46 > 0:18:53He continued to accumulate evidence and refine his theory for the next 14 years.
0:18:57 > 0:19:00But then, his hand was forced.
0:19:00 > 0:19:06In June 1858, 22 years after he got back from the Galapagos,
0:19:06 > 0:19:11here in his study in Down, he received a package
0:19:11 > 0:19:14from a naturalist who was working in what is now Indonesia.
0:19:15 > 0:19:20His name was Alfred Russell Wallace.
0:19:22 > 0:19:27He had been corresponding with Darwin for some years.
0:19:27 > 0:19:28But this package was different.
0:19:28 > 0:19:34It contained an essay that set out exactly the same idea as Darwin's...
0:19:34 > 0:19:36of evolution by natural selection.
0:19:39 > 0:19:46The idea had come to Wallace as he lay in his hut, semi-delirious in a malarial fever.
0:19:46 > 0:19:51But although his idea of natural selection was the same as Darwin's,
0:19:51 > 0:19:57he had not spent 20 years gathering the mountain of evidence to support it, as Darwin had done.
0:19:59 > 0:20:01But whose idea was it?
0:20:01 > 0:20:07In the end, the senior members of the Linnean Society decided that the fairest thing
0:20:07 > 0:20:11was for a brief outline of the theory from each of them to be read out, one after the other,
0:20:11 > 0:20:16at a meeting of the society, here in Burlington House in London.
0:20:17 > 0:20:19The Linnean, then as now,
0:20:19 > 0:20:24was the place where scientists studying the natural world held regular meetings
0:20:24 > 0:20:28to present and discuss papers about their observations and thoughts.
0:20:30 > 0:20:38The one held on July 1st 1858 was attended by only about 30 people.
0:20:38 > 0:20:41Neither of the authors were present.
0:20:41 > 0:20:45Wallace was 10,000 miles away in the East Indies,
0:20:45 > 0:20:52and Darwin was ill and devastated by the death a few days earlier of his infant son,
0:20:52 > 0:20:55so he was still at his home in Kent.
0:20:55 > 0:21:00As a consequence, the two papers had to be read by the secretary,
0:21:00 > 0:21:05and as far as we can tell, they made very little impression on anyone.
0:21:08 > 0:21:11Darwin spent the next year writing out his theory in detail.
0:21:11 > 0:21:16Then he sent the manuscript to his publisher, John Murray,
0:21:16 > 0:21:22whose firm - then as now - had offices in Albemarle Street, just off Piccadilly in London.
0:21:22 > 0:21:27Murray was the great publisher of his day
0:21:27 > 0:21:30and dealt with the works of Jane Austen and Lord Byron,
0:21:30 > 0:21:34whose first editions still line these office walls.
0:21:34 > 0:21:38Darwin regarded his work as simply a summary,
0:21:38 > 0:21:41but even so, it is 400 pages.
0:21:41 > 0:21:47It was published on November 24th 1859.
0:21:47 > 0:21:50This is not a first edition, more's the pity.
0:21:50 > 0:21:54First editions are worth literally hundreds of thousands of pounds.
0:21:54 > 0:21:57This is a 6th edition - my copy,
0:21:57 > 0:22:02which I bought as a boy, when I was 18, I notice.
0:22:02 > 0:22:05And it cost me the princely sum of one shilling.
0:22:10 > 0:22:15The first edition of 1,250 copies sold out immediately,
0:22:15 > 0:22:17and it went for a reprint.
0:22:17 > 0:22:19And then another reprint and another reprint.
0:22:19 > 0:22:25It's a book that contains very few technical terms - it's easily understood by anybody.
0:22:25 > 0:22:29And predictably, it caused an outrage,
0:22:29 > 0:22:33not only throughout this country, but indeed all the civilised world.
0:22:37 > 0:22:40What scandalised people most, it seems, was the implication
0:22:40 > 0:22:44that human beings were not specially created by God,
0:22:44 > 0:22:46as the Book of Genesis stated,
0:22:46 > 0:22:49but were descended from ape-like ancestors -
0:22:49 > 0:22:54a notion that provided a lot of scope for cartoonists.
0:22:56 > 0:23:00The leaders of the Church, headed by Samuel Wilberforce, the Bishop of Oxford,
0:23:00 > 0:23:03attacked it on the grounds that it demoted God
0:23:03 > 0:23:07and contradicted the story of Creation as told by the Bible.
0:23:09 > 0:23:13"That Mr Darwin should have wandered from this broad highway
0:23:13 > 0:23:20"of nature's works into the jungle of fanciful assumption is no small evil."
0:23:20 > 0:23:23"I have read your book with more pain than pleasure..."
0:23:23 > 0:23:27"It is the frenzied inspiration of the inhaler of mephitic gas."
0:23:27 > 0:23:29"Fails utterly."
0:23:33 > 0:23:38Darwin's theory implied that life had originated in simple forms,
0:23:38 > 0:23:42and had then become more and more complex.
0:23:42 > 0:23:48He knew perfectly well that the whole idea of evolution raised a lot of questions.
0:23:48 > 0:23:54In fact, some of those questions would not be answered until comparatively recently.
0:23:54 > 0:23:57But in his own time, many distinguished scientists
0:23:57 > 0:24:02raised what seemed to be insuperable difficulties.
0:24:02 > 0:24:05And foremost among them was Richard Owen,
0:24:05 > 0:24:11the man who 20 years earlier had named the extinct ground sloth in honour of Darwin.
0:24:13 > 0:24:19Over the years, the two men had developed a deep personal dislike of one another
0:24:19 > 0:24:22and had quarrelled frequently.
0:24:22 > 0:24:28It wasn't that Owen thought that the story of the Garden of Eden was literally correct,
0:24:28 > 0:24:32but nonetheless, he was a deeply religious man.
0:24:38 > 0:24:45He had, after all, ensured that his museum, which would display the wonders of Creation,
0:24:45 > 0:24:50echoed in its design the great Christian cathedrals of medieval Europe.
0:24:59 > 0:25:03And Owen knew about the diversity of life.
0:25:03 > 0:25:07Indeed, he had spent his whole career cataloguing it.
0:25:07 > 0:25:12But even so, he refused to believe that a species could change over time.
0:25:14 > 0:25:18He, and other pioneer Victorian geologists,
0:25:18 > 0:25:21as they established their comparatively new science,
0:25:21 > 0:25:26recognised that the outlines of the history of life could be deduced
0:25:26 > 0:25:28by examining the land around them.
0:25:31 > 0:25:35Look at these rocks in northern Scotland.
0:25:35 > 0:25:40We know from fossils that are associated with them that they are very ancient.
0:25:40 > 0:25:43And they are sand stones.
0:25:43 > 0:25:47Compacted sand that was laid down at the bottom of the sea,
0:25:47 > 0:25:50layer upon layer upon layer.
0:25:50 > 0:25:53But look how many layers there are!
0:26:09 > 0:26:12Clearly, those at the top must have been laid down
0:26:12 > 0:26:15after those beneath them.
0:26:15 > 0:26:21So as you descend from layer to layer, you are in effect going back in time.
0:26:21 > 0:26:26So a fossil species, if it comes from a particular layer,
0:26:26 > 0:26:29is of a particular age.
0:26:29 > 0:26:36And if you can recognise each one, then you can begin to piece together the outlines of life's history.
0:26:39 > 0:26:40Ah, Micraster...
0:26:40 > 0:26:45The ability to identify fossils and place them in their geological time zone
0:26:45 > 0:26:51was still an essential skill when I was at university a century later.
0:26:51 > 0:26:55We worked our way through drawers like these,
0:26:55 > 0:26:58which are full of fossils of one sort or another -
0:26:58 > 0:27:02but none of them have labels, only numbers.
0:27:02 > 0:27:06So you were expected to be able to pick up one...
0:27:07 > 0:27:11..and say, "Yes, that's a belemnite."
0:27:11 > 0:27:14Now, actually which belemnite it is, I can't remember now.
0:27:14 > 0:27:18And when you came to your practical exam,
0:27:18 > 0:27:21your examiners would produce one of these and say,
0:27:21 > 0:27:23"OK, what's that?"
0:27:23 > 0:27:25And you either knew or you didn't,
0:27:25 > 0:27:31and the way you knew was because of all the work you did in drawers like these, hour after hour.
0:27:36 > 0:27:41Owen did not deny the sequence in which all these different species appeared.
0:27:41 > 0:27:47But he believed that each was separate, each divinely created.
0:27:47 > 0:27:53Darwin's theory, however, required that there should be connections not just between similar species,
0:27:53 > 0:27:56but between the great animal groups.
0:27:58 > 0:28:04If fishes and reptiles and birds and mammals had all evolved from one another,
0:28:04 > 0:28:10then surely there must be intermediate forms between those great groups.
0:28:10 > 0:28:12And they were missing.
0:28:12 > 0:28:18And then, just two years after the publication of The Origin Of Species,
0:28:18 > 0:28:25Richard Owen himself purchased the most astonishing fossil for his museum.
0:28:27 > 0:28:31It had been found in this limestone quarry in Bavaria.
0:28:31 > 0:28:34The stone here splits into flat, smooth leaves
0:28:34 > 0:28:39that have been used as roofing tiles since Roman times.
0:28:41 > 0:28:43Most are blank.
0:28:43 > 0:28:47But occasionally, when you split them apart,
0:28:47 > 0:28:50they reveal a shrimp or a fish.
0:28:50 > 0:28:54It's almost impossible to resist the temptation
0:28:54 > 0:28:58of pulling down almost every boulder you see,
0:28:58 > 0:29:03and then opening it like a book, to look at each unopened page
0:29:03 > 0:29:07to see whether maybe it contains yet another fossil.
0:29:13 > 0:29:17But this fossil was something unprecedented.
0:29:17 > 0:29:23It is still one of the greatest of the treasures that are stored in the Natural History Museum.
0:29:24 > 0:29:29And this is it - it's called archaeopteryx.
0:29:29 > 0:29:33It has unmistakable feathers on its wings
0:29:33 > 0:29:36and down its tail.
0:29:36 > 0:29:41So Owen had no hesitation in calling it a bird.
0:29:41 > 0:29:44But it was unlike any other bird that anyone knew of,
0:29:44 > 0:29:49because it had claws on the front of its wings,
0:29:49 > 0:29:54and, as was later discovered, it didn't have a beak, but jaws with teeth in it.
0:29:54 > 0:29:58And a line of bones supporting its tail.
0:29:58 > 0:30:03So it was part reptile, part bird.
0:30:04 > 0:30:08Here was a link between those two great groups
0:30:08 > 0:30:10that was no longer missing.
0:30:10 > 0:30:15Gosh, you really can see the filaments there.
0:30:20 > 0:30:27Other examples of the same creature show its feathers even more clearly.
0:30:27 > 0:30:33We know from the bones of archaeopteryx that it was, at best, a very poor flyer.
0:30:33 > 0:30:38So it's not surprising that eventually it was superseded
0:30:38 > 0:30:41by more modern, more efficient birds.
0:30:41 > 0:30:46And that's the fate of these links between great groups.
0:30:46 > 0:30:49Eventually they become extinct,
0:30:49 > 0:30:54and the only way we know they existed is from their fossilised remains.
0:30:54 > 0:30:58Even so, there is a bird alive today
0:30:58 > 0:31:04that illustrates the link between modern birds and reptiles.
0:31:07 > 0:31:11The hoatzin nests in the swamps of tropical South America.
0:31:11 > 0:31:17There are cayman in the water beneath, ready to snap up any chick that might fall from its nest,
0:31:17 > 0:31:19so an ability to hold on tight is very valuable.
0:31:19 > 0:31:23And the nestlings have a very interesting way of doing that.
0:31:24 > 0:31:30The young still have claws on the front of their wings, as archaeopteryx did.
0:31:30 > 0:31:35Here is vivid evidence that the wings of birds are modified forelegs
0:31:35 > 0:31:37and once had toes with claws on them.
0:31:38 > 0:31:43There's another creature alive today that represents a link between the great animal groups,
0:31:43 > 0:31:48a descendant of a group of reptiles that took a different evolutionary course
0:31:48 > 0:31:52and evolved not feathers, but fur -
0:31:52 > 0:31:54the platypus.
0:31:54 > 0:31:58When specimens of this creature first reached Europe from Australia
0:31:58 > 0:32:00at the very end of the 18th century,
0:32:00 > 0:32:04people refused to believe their eyes.
0:32:04 > 0:32:06They said it was a hoax -
0:32:06 > 0:32:12bits and pieces of different creatures rather crudely sewn together.
0:32:12 > 0:32:15And yet in a way those early sceptics were right.
0:32:15 > 0:32:20The platypus is the most extraordinary mixture of different animals.
0:32:20 > 0:32:23It's part mammal and part reptile.
0:32:23 > 0:32:27And so it can give us some idea of how the first mammals developed.
0:32:28 > 0:32:35When it comes to breed, it does something that separates it from all other mammals except one.
0:32:35 > 0:32:39In its nest, deep in a burrow, it lays eggs.
0:32:39 > 0:32:42It's this that links the platypus with the reptiles,
0:32:42 > 0:32:45and this that entitles it to be regarded
0:32:45 > 0:32:48as the most primitive living mammal.
0:32:50 > 0:32:53So the links between the great animal groups
0:32:53 > 0:32:56are not, in fact, missing,
0:32:56 > 0:33:00but exist both as fossils and as living animals.
0:33:00 > 0:33:05Although the fossil record provides an answer to the problem
0:33:05 > 0:33:10of missing links, it also posed a major problem.
0:33:10 > 0:33:13It started very abruptly.
0:33:13 > 0:33:16The earliest known fossils in Darwin's time
0:33:16 > 0:33:20came from a formation called the Cambrian,
0:33:20 > 0:33:22and there were two main kinds -
0:33:22 > 0:33:27these, which look like fretsaw blades and are called graptolite,
0:33:27 > 0:33:32and these, like giant woodlice, which are called trilobites.
0:33:32 > 0:33:35Could it really be that life on Earth started
0:33:35 > 0:33:39with creatures as complex as these?
0:33:54 > 0:33:59As a boy, I was a passionate collector of fossils.
0:33:59 > 0:34:02I grew up in the city of Leicester,
0:34:02 > 0:34:07and I knew that in this area, not far from the city, called Charnwood Forest,
0:34:07 > 0:34:13there were the oldest rocks in the world, older even than the Cambrian.
0:34:13 > 0:34:17So therefore, by definition, they would be without fossils.
0:34:17 > 0:34:22There was no point in me looking for fossils in these ancient rocks.
0:34:38 > 0:34:41There were, it's true, very rarely,
0:34:41 > 0:34:45some rather odd shapes in these rocks,
0:34:45 > 0:34:47like this one here.
0:34:47 > 0:34:52But they were dismissed as being some kind of mechanical aberration.
0:34:52 > 0:34:54I mean, after all,
0:34:54 > 0:34:59how could there be anything living in these extremely ancient rocks?
0:35:00 > 0:35:03And then in 1957,
0:35:03 > 0:35:10a schoolboy with rather more patience and perspicacity than I had
0:35:10 > 0:35:13found something really remarkable -
0:35:13 > 0:35:18and undeniably, the remains of a living creature.
0:35:20 > 0:35:23And here it is in Leicester Museum,
0:35:23 > 0:35:26where it's been brought for safekeeping.
0:35:26 > 0:35:29It's called Charnia.
0:35:29 > 0:35:35Who could doubt that this is the impression of a living organism?
0:35:35 > 0:35:39It has a central stem, and branches on either side.
0:35:39 > 0:35:43In fact, it seems to have been something like the sea pens
0:35:43 > 0:35:47that today grow on coral reefs.
0:35:47 > 0:35:52Since its discovery, a whole range of organisms have been found
0:35:52 > 0:35:56in rocks of this extreme age,
0:35:56 > 0:36:01not only here in the Charnwood Forest, but in many other different parts of the world.
0:36:02 > 0:36:07Fossil hunters searching these rocks in the Ediacra Hills of Australia
0:36:07 > 0:36:11had also been discovering other strange shapes.
0:36:12 > 0:36:16At first, many scientists refused to believe
0:36:16 > 0:36:20that these faint impressions were the remains of jellyfish.
0:36:20 > 0:36:24But by now, enough specimens had been discovered to make quite sure
0:36:24 > 0:36:26that that indeed is what they are.
0:36:34 > 0:36:40So now we know that life did not begin suddenly with those complex animals of the Cambrian.
0:36:43 > 0:36:45It started much, much earlier,
0:36:45 > 0:36:50first with simple microscopic forms which eventually became bigger,
0:36:50 > 0:36:55but which were still so soft and delicate that they only very rarely left any mark in the rocks.
0:36:58 > 0:37:04The question of the age of the Earth posed another problem for Darwin's theory.
0:37:04 > 0:37:11In the 17th century, an Irish bishop had used the genealogies recorded in the Bible
0:37:11 > 0:37:14that lead back to Adam to work out that the week of Creation
0:37:14 > 0:37:19must have taken place in the year 4004 BC.
0:37:19 > 0:37:22That may seem to us to be a very naive way of doing things,
0:37:22 > 0:37:25but what other method was there anyway?
0:37:26 > 0:37:32The Victorian geologists had already concluded that the Earth must be millions of years old.
0:37:32 > 0:37:37But how many millions, no-one could say.
0:37:37 > 0:37:41Then, less than 50 years after the publication of The Origin,
0:37:41 > 0:37:46a discovery was made in what seemed a totally disconnected branch of science
0:37:46 > 0:37:48that would ultimately provide the answer.
0:37:50 > 0:37:53A Polish woman working in Paris, Marie Curie,
0:37:53 > 0:37:58discovered that some rocks contained an element called uranium
0:37:58 > 0:38:04that decays over time at a steady rate through a process called radiation.
0:38:04 > 0:38:09Today, a century after she made her extraordinary discovery,
0:38:09 > 0:38:11the method of dating by measuring
0:38:11 > 0:38:15changes in radioactivity has become greatly refined.
0:38:19 > 0:38:24This is a sample taken from those very ancient rocks in Charnwood Forest.
0:38:24 > 0:38:31And these tiny crystals are revealed to be 562 million years old.
0:38:31 > 0:38:35That provides more than enough time
0:38:35 > 0:38:39for natural selection to produce the procession of fossils
0:38:39 > 0:38:44that eventually leads to the living animals and plants we know today.
0:38:45 > 0:38:47But there was another objection.
0:38:47 > 0:38:51If all animals within a group have a common origin,
0:38:51 > 0:38:55how is it that some kinds of animals are distributed
0:38:55 > 0:39:00throughout the continents of the world, except for Antarctica?
0:39:00 > 0:39:06How is it that, for example, frogs in Europe and Africa
0:39:06 > 0:39:09are also found here in South America,
0:39:09 > 0:39:11on the other side of the Atlantic Ocean,
0:39:11 > 0:39:17bearing in mind that frogs have permeable skins and can't survive in sea water?
0:39:17 > 0:39:20Darwin himself had a couple of suggestions.
0:39:20 > 0:39:25One was that they might have floated across accidentally on rafts of vegetation,
0:39:25 > 0:39:30and the other is that maybe there were land bridges between the continents,
0:39:30 > 0:39:34but even he was not convinced by either explanation.
0:39:40 > 0:39:46Even as late as 1947, when I was a geology student here at Cambridge,
0:39:46 > 0:39:50there was no convincing explanation.
0:39:50 > 0:39:55It's true that back in 1912, a German geologist had suggested
0:39:55 > 0:39:59that at one time in the very remote, distant past,
0:39:59 > 0:40:04all the continents of the Earth that we know today were grouped together
0:40:04 > 0:40:07to form one huge super-continent,
0:40:07 > 0:40:13and that over time this broke up and the pieces drifted apart.
0:40:13 > 0:40:16That would have provided an answer.
0:40:16 > 0:40:21But when I asked the professor of geology here who was lecturing to us
0:40:21 > 0:40:24why he didn't tell us about that in his lectures,
0:40:24 > 0:40:28he replied, rather loftily I must say,
0:40:28 > 0:40:35"When you can demonstrate to me that there is a force on Earth that can move the continents by a millimetre,
0:40:35 > 0:40:42"I will consider it, But until then, the idea is sheer moonshine, dear boy!"
0:40:44 > 0:40:47But then, in the 1960s,
0:40:47 > 0:40:51it became possible to map the sea floor in detail,
0:40:51 > 0:40:55and it was discovered not only that the continents have shifted
0:40:55 > 0:40:59in just the way that the German geologist had suggested,
0:40:59 > 0:41:01but that they were still moving.
0:41:03 > 0:41:06New rock wells up from deep below the Earth's crust,
0:41:06 > 0:41:13and flows away on either side of the mid-ocean ridges, carrying the continents with it.
0:41:13 > 0:41:17Amphibians had originally evolved on this super-continent
0:41:17 > 0:41:22and had then travelled on each of its various fragments as they drifted apart.
0:41:22 > 0:41:24Problem solved!
0:41:28 > 0:41:31Perhaps the biggest problem of all for most people
0:41:31 > 0:41:36was the argument put forward for the existence of God
0:41:36 > 0:41:42at the beginning of the 19th century by an Anglican clergyman called William Paley.
0:41:42 > 0:41:49He said, supposing you were walking in the countryside and you picked up something like this.
0:41:49 > 0:41:52You would know from looking at it
0:41:52 > 0:41:57that it had been designed to tell the time.
0:41:58 > 0:42:02There must, therefore, be a designer.
0:42:02 > 0:42:07And the same argument would apply if you looked at one of the intricate structures found in nature,
0:42:07 > 0:42:10such as the human eye.
0:42:10 > 0:42:15And the only designer of the human eye could be God.
0:42:15 > 0:42:20Anti-evolutionists maintain that the eye would only work
0:42:20 > 0:42:24if it was complete in all its details.
0:42:24 > 0:42:28Darwin, on the other hand, argued that the eye had developed,
0:42:28 > 0:42:33becoming increasingly complex over a long period of time.
0:42:33 > 0:42:37That would only work if each stage of development
0:42:37 > 0:42:39was an improvement on the previous one,
0:42:39 > 0:42:46and today we know enough about the animal kingdom to know that that is indeed the case.
0:42:47 > 0:42:52Some very simple animals have nothing more than light-sensitive spots
0:42:52 > 0:42:57that enable them to tell the difference between light and dark.
0:42:57 > 0:43:01But if a patch of such spots formed even the shallowest of pits,
0:43:01 > 0:43:04one edge of the pit would throw a shadow,
0:43:04 > 0:43:08and so reveal the direction of light.
0:43:08 > 0:43:14If the pit got deeper and started to close, then light would form a blurred image.
0:43:14 > 0:43:18Mucus secreted by the cells would bend the light and focus it.
0:43:18 > 0:43:22If this mucus hardened, it would form a proper lens
0:43:22 > 0:43:26and transmit a brighter and clearer image.
0:43:26 > 0:43:29All these different fully-functional stages
0:43:29 > 0:43:35at different levels of complexity are found in living animals today.
0:43:35 > 0:43:41This single-celled creature has one of those light-sensitive spots.
0:43:41 > 0:43:45Flatworms have a small pit containing light spots,
0:43:45 > 0:43:49so they can detect the shadow of a predator.
0:43:49 > 0:43:55A snail's blurry vision is good enough to enable it to find its way to food.
0:43:55 > 0:44:01And the octopus has an eye with a proper lens and can see as much detail as we can.
0:44:06 > 0:44:11So the structure of the human eye does not demand the assistance of a supernatural designer.
0:44:11 > 0:44:14It can have evolved gradually,
0:44:14 > 0:44:19with each stage bringing a real advantage, as Darwin's theory demands.
0:44:24 > 0:44:26Natural selection, of course,
0:44:26 > 0:44:32requires that an animal's characteristics are handed from one generation to the next.
0:44:32 > 0:44:35It's obvious that children resemble their parents.
0:44:35 > 0:44:38Anyone knows that.
0:44:38 > 0:44:42But when you come to think of it, how does that come about?
0:44:42 > 0:44:46In Darwin's time, nobody had the faintest idea
0:44:46 > 0:44:50about the mechanism or the rules that governed that process,
0:44:50 > 0:44:56except perhaps for one man who was working in the city of Brno,
0:44:56 > 0:45:03in what is now the Czech Republic, at exactly the same time that Darwin was writing his book in Kent.
0:45:03 > 0:45:06That man's name was Gregor Mendel.
0:45:08 > 0:45:10He discovered the laws of inheritance
0:45:10 > 0:45:13by breeding thousands of pea plants
0:45:13 > 0:45:18and observing how they changed from one generation to the next.
0:45:18 > 0:45:21He found that while many characteristics
0:45:21 > 0:45:24were passed down directly from one generation to another,
0:45:24 > 0:45:29others could actually skip a generation. How could that happen?
0:45:29 > 0:45:35Mendel explained this by suggesting that each plant, each organism,
0:45:35 > 0:45:40contained within it factors which were responsible
0:45:40 > 0:45:45for creating those particular characteristics.
0:45:45 > 0:45:47Today, we call those things genes,
0:45:47 > 0:45:53but nobody had any idea how they worked until 100 years after Mendel's time.
0:45:53 > 0:45:58And then the answer was discovered in Cambridge.
0:46:01 > 0:46:08In 1953, here in the Cavendish laboratories, two young researchers,
0:46:08 > 0:46:13Francis Crick and James Watson, were building models like this.
0:46:13 > 0:46:19It was their way of thinking about and investigating the structure
0:46:19 > 0:46:26of a complex molecule that's found in the genes of all animals - DNA.
0:46:26 > 0:46:30The crucial bit are these chains,
0:46:30 > 0:46:32which encircle the rod -
0:46:35 > 0:46:39and here is a second - and entwine.
0:46:39 > 0:46:42This is a double helix.
0:46:44 > 0:46:49The workings of the DNA molecule are now understood in such detail
0:46:49 > 0:46:53that we can demonstrate something that is truly astounding.
0:46:54 > 0:46:58A gene taken from one animal can function in another.
0:46:59 > 0:47:03The gene that causes a jellyfish to be luminous, for example,
0:47:03 > 0:47:08transplanted into a mouse, will make that mouse luminous.
0:47:15 > 0:47:20The genetic code can also reveal relationships.
0:47:20 > 0:47:24Even our law courts accept that DNA fingerprinting
0:47:24 > 0:47:28can establish whether a man is the father of a particular child.
0:47:30 > 0:47:35And it can also reveal whether one kind of animal is related to another.
0:47:41 > 0:47:44It proves, for example, that kangaroos -
0:47:44 > 0:47:48ground-living animals that run with great leaps -
0:47:48 > 0:47:53are closely related to koalas that have taken to climbing trees.
0:47:53 > 0:47:59That insect-eating shrews have cousins that took to the air
0:47:59 > 0:48:01in search of insects - bats.
0:48:01 > 0:48:06And that one branch of the elephant family, way back in geological history,
0:48:06 > 0:48:10took to the water and became sea cows.
0:48:10 > 0:48:17So, 150 years after the publication of Darwin's revolutionary book,
0:48:17 > 0:48:22modern genetics has confirmed its fundamental truth -
0:48:22 > 0:48:25all life is related.
0:48:25 > 0:48:28And it enables us to construct with confidence
0:48:28 > 0:48:35the complex tree that represents the history of life.
0:48:35 > 0:48:37It began in the sea,
0:48:37 > 0:48:40some 3,000 million years ago.
0:48:40 > 0:48:45Complex chemical molecules began to clump together
0:48:45 > 0:48:49to form microscopic blobs - cells.
0:48:51 > 0:48:55These were the seeds from which the tree of life developed.
0:48:55 > 0:48:59They were able to split, replicating themselves as bacteria do.
0:48:59 > 0:49:04And as time passed, they diversified into different groups.
0:49:05 > 0:49:09Some remained attached to one another, so that they formed chains.
0:49:09 > 0:49:12We know them today as algae.
0:49:12 > 0:49:16Others formed hollow balls which collapsed upon themselves,
0:49:16 > 0:49:20creating a body with an internal cavity.
0:49:20 > 0:49:24They were the first multi-celled organisms -
0:49:24 > 0:49:28sponges are their direct descendents.
0:49:28 > 0:49:34As more variations appeared, the tree of life grew and became more diverse.
0:49:34 > 0:49:40Some organisms became more mobile and developed a mouth that opened into a gut.
0:49:43 > 0:49:48Others had bodies stiffened by an internal rod.
0:49:48 > 0:49:52They understandably developed sense organs around their front end.
0:49:54 > 0:49:57A related group had bodies that were divided into segments
0:49:57 > 0:50:03with little projections on either side that helped them to move around on the sea floor.
0:50:03 > 0:50:07Some of these segmented creatures developed hard protective skins
0:50:07 > 0:50:10which gave their bodies some rigidity.
0:50:10 > 0:50:15So now the seas were filled with a great variety of animals.
0:50:16 > 0:50:19And then, around 450 million years ago,
0:50:19 > 0:50:25some of these armoured creatures crawled up, out of the water and ventured onto land.
0:50:28 > 0:50:33And here, the tree of life branched into a multitude of different species
0:50:33 > 0:50:37that exploited this new environment in all kinds of ways.
0:50:39 > 0:50:43One group of them developed elongated flaps on their backs,
0:50:43 > 0:50:48which, over many generations, eventually developed into wings.
0:50:48 > 0:50:51The insects had arrived.
0:50:51 > 0:50:56Life moved into the air and diversified into myriad forms.
0:50:59 > 0:51:01Meanwhile, back in the seas,
0:51:01 > 0:51:07those creatures with the stiffening rod in their bodies had strengthened it by encasing it in bone.
0:51:09 > 0:51:15A skull developed, with a hinged jaw that could grab and hold on to prey.
0:51:15 > 0:51:18They grew bigger, and developed fins
0:51:18 > 0:51:22equipped with muscles that enabled them to swim with speed and power.
0:51:23 > 0:51:28So fish now dominated the waters of the world.
0:51:28 > 0:51:33One group of them developed the ability to gulp air from the water surface.
0:51:36 > 0:51:42Their fleshy fins became weight-supporting legs and 375 million years ago,
0:51:42 > 0:51:48a few of these backboned creatures followed the insects onto the land.
0:51:48 > 0:51:54They were amphibians with wet skins and they had to return to water to lay their eggs,
0:51:54 > 0:51:58but some of their descendents evolved dry, scaly skins
0:51:58 > 0:52:04and broke their link with water by laying eggs with watertight shells.
0:52:05 > 0:52:13These creatures, the reptiles, were the ancestors of today's tortoises, snakes, lizards and crocodiles.
0:52:13 > 0:52:20And of course they included the group that back then came to dominate the land - the dinosaurs.
0:52:22 > 0:52:27But 65 million years ago, a great disaster overtook the Earth.
0:52:32 > 0:52:36Whatever its cause, a great proportion of animals were exterminated.
0:52:36 > 0:52:40All the dinosaurs disappeared, except for one branch
0:52:40 > 0:52:43whose scales had become modified into feathers.
0:52:45 > 0:52:46They were the birds.
0:52:46 > 0:52:49While they spread through the skies,
0:52:49 > 0:52:55a small, seemingly insignificant group of survivors began to increase in numbers on the ground beneath.
0:52:57 > 0:53:00These creatures differed from their competitors
0:53:00 > 0:53:04in that their bodies were warm and insulated with coats of fur -
0:53:04 > 0:53:07they were the first mammals.
0:53:07 > 0:53:13With much of the land left vacant after the great catastrophe, they now had their chance.
0:53:13 > 0:53:17Their warm, insulated bodies enabled them to be active at all times,
0:53:17 > 0:53:20at night as well as during the day.
0:53:20 > 0:53:25And in all places, from the Arctic to the Tropics.
0:53:25 > 0:53:29In water as well as on land.
0:53:29 > 0:53:33On grassy plains and up in the trees.
0:54:09 > 0:54:10HE CHUCKLES
0:54:14 > 0:54:20There can be no doubt about our close relationship to these chimpanzees.
0:54:20 > 0:54:22Our bodies are so similar,
0:54:22 > 0:54:26the proportions of our limbs or our faces may differ,
0:54:26 > 0:54:28but otherwise we are very, very similar.
0:54:30 > 0:54:34The arrangement of our internal organs, the chemistry of our blood,
0:54:34 > 0:54:39the way our bodies work... All these are almost identical.
0:54:39 > 0:54:42And DNA confirms that.
0:54:42 > 0:54:47Indeed, we are as closely related to chimpanzees
0:54:47 > 0:54:52and the rest of the apes and monkeys as, say, lions are to tigers
0:54:52 > 0:54:54and to the rest of the cat family.
0:55:18 > 0:55:23Suddenly, an image from our remote past comes vividly to light -
0:55:23 > 0:55:25the time when our distant ancestors,
0:55:25 > 0:55:29in order to keep up with the changing environment,
0:55:29 > 0:55:32had to wade and keep their heads above water
0:55:32 > 0:55:35in order to find food.
0:55:35 > 0:55:39That crucial moment when our far distant ancestors
0:55:39 > 0:55:45took a step away from being apes and a step towards humanity.
0:55:59 > 0:56:04The Natural History Museum is one of the most important museums of its kind in the world.
0:56:04 > 0:56:09Richard Owen brought it into existence, but over a century later,
0:56:09 > 0:56:14discoveries from many branches of science have shown that his belief
0:56:14 > 0:56:20that species can never change, but always remain exactly the same, was mistaken.
0:56:40 > 0:56:46It was Charles Darwin's profound insights that have proved to be true.
0:56:46 > 0:56:49And now, to mark the 200th anniversary of his birth,
0:56:49 > 0:56:54his statue is being taken from its out-of-the-way location
0:56:54 > 0:56:58to be placed centre stage in the main hall.
0:57:14 > 0:57:19Darwin's great insight revolutionised the way in which we see the world.
0:57:19 > 0:57:23We now understand why there are so many different species,
0:57:23 > 0:57:27why they are distributed in the way they are around the world.
0:57:27 > 0:57:32And why their bodies and our bodies are shaped in the way that they are.
0:57:32 > 0:57:36Because we understand that bacteria evolve,
0:57:36 > 0:57:40we can devise methods of dealing with the diseases they cause.
0:57:40 > 0:57:43And because we can disentangle the complex relationships
0:57:43 > 0:57:46between animals and plants in a natural community,
0:57:46 > 0:57:52we can foresee some of the consequences when we start to interfere with those communities.
0:57:54 > 0:57:59But above all, Darwin has shown us that we are not apart from the natural world.
0:57:59 > 0:58:03We do not have dominion over it.
0:58:03 > 0:58:07We are subject to its laws and processes,
0:58:07 > 0:58:14as are all other animals on Earth - to which indeed we are related.
0:58:15 > 0:58:17HE CHUCKLES
0:59:01 > 0:59:04Subtitles by Red Bee Media Ltd
0:59:04 > 0:59:07E-mail subtitling@bbc.co.uk