0:00:02 > 0:00:05How did two small animals from opposite ends of the world
0:00:05 > 0:00:07upset the reputations of leading scientists
0:00:07 > 0:00:10and change our understanding of evolution?
0:00:12 > 0:00:14I've been lucky enough, one way or another,
0:00:14 > 0:00:18to meet some of our planet's most enchanting creatures.
0:00:18 > 0:00:21But some I find particularly intriguing.
0:00:23 > 0:00:27We've known about some of these creatures for centuries.
0:00:27 > 0:00:30Others we have discovered more recently.
0:00:31 > 0:00:34In this series, I share their stories
0:00:34 > 0:00:38and reveal why they really are natural curiosities.
0:00:45 > 0:00:48In this programme, we explore the stories of two animals
0:00:48 > 0:00:54that sent shock waves through the scientific world and beyond.
0:00:54 > 0:00:58One is a toad that became the centre of a scientific storm
0:00:58 > 0:01:02and caused accusations of fakery in the early part of the 20th century.
0:01:05 > 0:01:06The other is an Australian animal
0:01:06 > 0:01:10that baffled the greatest thinkers of Victorian Europe
0:01:10 > 0:01:13and caused many to question whether it was even real.
0:01:26 > 0:01:29When the first Europeans arrived in Australia,
0:01:29 > 0:01:32they were shocked by the animals they found there.
0:01:32 > 0:01:37Nothing in Europe could compare with the bizarre upright grazers
0:01:37 > 0:01:39hopping across the grassland landscape,
0:01:39 > 0:01:42carrying their young in pouches.
0:01:42 > 0:01:47Kangaroos were obvious oddities, but another even stranger creature
0:01:47 > 0:01:50also caught the attention of early settlers.
0:01:50 > 0:01:54It lived along river banks and swam in the water.
0:01:54 > 0:01:58Those first Europeans who saw it called it a water mole,
0:01:58 > 0:02:00but that name didn't last long.
0:02:02 > 0:02:06Inside this box is one of the first specimens of platypus
0:02:06 > 0:02:09ever to be seen outside Australia.
0:02:16 > 0:02:20It was sent to England in 1798 by Captain John Hunter,
0:02:20 > 0:02:23the governor of New South Wales.
0:02:23 > 0:02:27This one small animal would take the scientific world by storm
0:02:27 > 0:02:29and transform the careers and reputations
0:02:29 > 0:02:33of some of the leading thinkers of the time.
0:02:34 > 0:02:38The platypus seemed to be a concoction of different animals.
0:02:38 > 0:02:43Part-bird, with its bill, and part mammal, with its furry body.
0:02:43 > 0:02:46When Charles Darwin first encountered one in the wild,
0:02:46 > 0:02:48it baffled even him.
0:02:48 > 0:02:52"Surely," he wrote, "two distinct creators must have been at work."
0:02:55 > 0:02:59The task of describing the first platypus specimen
0:02:59 > 0:03:01fell to naturalist George Shaw,
0:03:01 > 0:03:04who worked in the department of natural history
0:03:04 > 0:03:05in the British Museum.
0:03:05 > 0:03:10He viewed this remarkable specimen with a fair degree of caution.
0:03:11 > 0:03:15This is a first edition of a journal called A Naturalist's Miscellany,
0:03:15 > 0:03:19which was published a few years after his examination.
0:03:19 > 0:03:22It contains not only an article by him,
0:03:22 > 0:03:25but a nice picture of the animal concerned.
0:03:25 > 0:03:31At the end, he says, "On a subject so extraordinary as the present,
0:03:31 > 0:03:35"a degree of scepticism is not only pardonable but laudable.
0:03:35 > 0:03:39"I ought, perhaps, to acknowledge that I almost doubt the testimony
0:03:39 > 0:03:45"of my own eyes with respect to the structure of this animal's beak."
0:03:45 > 0:03:47It's said that Shaw was so determined to make sure
0:03:47 > 0:03:50that he was not a victim of some elaborate hoax
0:03:50 > 0:03:52that he actually cut behind the bill
0:03:52 > 0:03:54to make sure that it hadn't been sewn on
0:03:54 > 0:03:56by some mischievous forger.
0:03:58 > 0:04:01In the late 18th century, the world was opening up.
0:04:01 > 0:04:05Travellers were returning from overseas with all kinds of wonders.
0:04:05 > 0:04:07Among them were specimens of creatures
0:04:07 > 0:04:10that people had come to think of as being myths,
0:04:10 > 0:04:12such as mermen and mermaids.
0:04:12 > 0:04:14These were, of course, hoaxes,
0:04:14 > 0:04:17put together with parts from different animals.
0:04:17 > 0:04:21So it's understandable that Shaw had doubts about the authenticity
0:04:21 > 0:04:23of his new furry specimen.
0:04:25 > 0:04:29Despite his misgivings, he decided to give it a scientific name -
0:04:29 > 0:04:33platypus, which means flat-footed.
0:04:33 > 0:04:34He didn't know, however,
0:04:34 > 0:04:37that a beetle had already been given this name.
0:04:37 > 0:04:42Some years later, another taxonomist very properly gave it a new one -
0:04:42 > 0:04:46Ornithorhynchus, which means bird snout.
0:04:46 > 0:04:49But platypus is still the name that most people use.
0:04:51 > 0:04:53But what type of creature was it?
0:04:53 > 0:04:57George Shaw believed it to be a mammal because of its furry body.
0:04:59 > 0:05:04All mammals feed on milk during the first part of their lives.
0:05:04 > 0:05:08Milk that is produced by their mother's mammary glands.
0:05:08 > 0:05:12But could an animal with a large, flat bill really suckle?
0:05:12 > 0:05:15Some scientists thought that was impossible.
0:05:15 > 0:05:18And, anyway, they couldn't believe the platypus and the monkey
0:05:18 > 0:05:21could belong to the same group of animals.
0:05:21 > 0:05:23But that view was to change.
0:05:24 > 0:05:28Some 30 years after George Shaw described the platypus,
0:05:28 > 0:05:30a German naturalist, Johann Meckel,
0:05:30 > 0:05:35produced this wonderful collection of anatomical studies.
0:05:35 > 0:05:38Meckel's meticulous and detailed work would help identify
0:05:38 > 0:05:41the true nature of this animal.
0:05:41 > 0:05:42Here...
0:05:44 > 0:05:47..we can see his drawing of a male platypus,
0:05:47 > 0:05:50showing clearly the claw.
0:05:50 > 0:05:53Meckel also reported the existence of simple glands
0:05:53 > 0:05:56beneath the thick fur of the female platypus,
0:05:56 > 0:05:59glands that he suggested secreted milk.
0:06:00 > 0:06:04There could be little doubt that these glands produced something.
0:06:04 > 0:06:07But even then, several scientists doubted Meckel's claims,
0:06:07 > 0:06:09and suggested rather desperately
0:06:09 > 0:06:13that the glands secreted not milk but a lubricant.
0:06:13 > 0:06:15Today we know that Meckel was right.
0:06:15 > 0:06:18I was once able to use an optical probe
0:06:18 > 0:06:20to peer into a platypus's burrow
0:06:20 > 0:06:24and see a female platypus nurturing her single baby.
0:06:26 > 0:06:30Yes. There it is. It's milk.
0:06:30 > 0:06:32Milk is the perfect food.
0:06:32 > 0:06:37It provides the growing youngster with everything it wants.
0:06:37 > 0:06:40Only mammals produce milk.
0:06:40 > 0:06:43In most mammals, of course, it comes from a nipple.
0:06:43 > 0:06:46But in this very primitive mammal,
0:06:46 > 0:06:48it simply oozes through the skin.
0:06:50 > 0:06:55But 19th-century biologists had no such tricks to help them.
0:06:55 > 0:06:58They had to unravel the strange biology of Australian mammals
0:06:58 > 0:07:02from just a few shrivelled remains of long-dead specimens.
0:07:04 > 0:07:0740 years after their discovery of the platypus,
0:07:07 > 0:07:08a brilliant young anatomist -
0:07:08 > 0:07:11who was to become a giant to 19th-century science -
0:07:11 > 0:07:13joined the debate.
0:07:13 > 0:07:16This is a statue of Richard Owen.
0:07:16 > 0:07:18Owen was a formidable man.
0:07:18 > 0:07:22The founding director of the Natural History Museum in Britain,
0:07:22 > 0:07:26he was once described as having so much brain as to require two hats.
0:07:27 > 0:07:32The platypus would become a central character in Owen's career.
0:07:32 > 0:07:33His worked on this small creature
0:07:33 > 0:07:35would help him secure election
0:07:35 > 0:07:37to the prestigious Royal Society,
0:07:37 > 0:07:40an exclusive group of scientists and thinkers.
0:07:41 > 0:07:45Owen had an advantage over his European colleagues.
0:07:46 > 0:07:49Australia was a British colony,
0:07:49 > 0:07:51and Owen used his contacts
0:07:51 > 0:07:52to supply him with specimens.
0:07:55 > 0:07:58Eventually, two baby platypuses arrived
0:07:58 > 0:08:00and it was obvious to him
0:08:00 > 0:08:03that they would have no difficulty in suckling.
0:08:04 > 0:08:06They'd not yet developed the bill
0:08:06 > 0:08:08that would have made it awkward.
0:08:08 > 0:08:11So he accepted the platypus babies,
0:08:11 > 0:08:12like other mammal babies,
0:08:12 > 0:08:14were indeed raised on milk.
0:08:17 > 0:08:21But the biggest mystery of the platypus was still unsolved.
0:08:22 > 0:08:24Did this animal lay eggs,
0:08:24 > 0:08:27just like reptiles or birds,
0:08:27 > 0:08:29or did it give birth to live young?
0:08:30 > 0:08:32Owen was at the heart of that debate.
0:08:33 > 0:08:36These jars contain the bodies of several platypus
0:08:36 > 0:08:39that were shot and sent back here to the museum
0:08:39 > 0:08:41for Richard Owen to examine.
0:08:41 > 0:08:44His determination to prove whether or not they laid eggs
0:08:44 > 0:08:49was going to cause the death of quite a number of platypus.
0:08:49 > 0:08:53The Australian aborigines were absolutely clear they did lay eggs,
0:08:53 > 0:08:56but that was not good enough for Owen.
0:08:56 > 0:08:58He knew better than any Australian aboriginal.
0:08:59 > 0:09:01He did concede that it might be
0:09:01 > 0:09:05that the eggs were retained inside the body and hatched there,
0:09:05 > 0:09:07so that the young were born live -
0:09:07 > 0:09:09but that's as far as he'd go.
0:09:09 > 0:09:11Eggs were also sent back.
0:09:11 > 0:09:13Some of them were fake,
0:09:13 > 0:09:15and some of them belonged to snakes.
0:09:15 > 0:09:17It was going to be some decades
0:09:17 > 0:09:19before the puzzle of the platypus
0:09:19 > 0:09:20was finally solved.
0:09:23 > 0:09:25The platypus now became embroiled
0:09:25 > 0:09:27in the greatest scientific debate
0:09:27 > 0:09:29of the Victorian era.
0:09:29 > 0:09:31Did species evolve,
0:09:31 > 0:09:33or were they created?
0:09:33 > 0:09:35Darwin's Theory of Evolution
0:09:35 > 0:09:38suggested that species could change over time,
0:09:38 > 0:09:40so an intermediate form that laid eggs
0:09:40 > 0:09:44but had fur like a mammal, was to be expected -
0:09:44 > 0:09:46but that was too much of an stretch,
0:09:46 > 0:09:49even for Owen's great brain.
0:09:49 > 0:09:50In 1884,
0:09:50 > 0:09:53more than 80 years after this first platypus specimen
0:09:53 > 0:09:56had been examined by George Shaw,
0:09:56 > 0:09:59William Hay Caldwell arrived in Australia
0:09:59 > 0:10:02funded by a Royal Society scholarship.
0:10:02 > 0:10:05One of his main aims was to solve the platypus egg question
0:10:05 > 0:10:07once and for all.
0:10:07 > 0:10:09After several months in Queensland
0:10:09 > 0:10:11and with the help of the local aborigines,
0:10:11 > 0:10:13he finally got the answer.
0:10:13 > 0:10:15He shot a female platypus
0:10:15 > 0:10:19soon after she had laid an egg in her nest burrow,
0:10:19 > 0:10:22with a second egg about to emerge from her vent.
0:10:22 > 0:10:25And they look like this.
0:10:25 > 0:10:28It was, at last, visible evidence
0:10:28 > 0:10:31that this animal did indeed lay eggs.
0:10:31 > 0:10:34He sent a telegram to a scientific gathering in Montreal.
0:10:34 > 0:10:36It was brief and to the point.
0:10:36 > 0:10:39"Monotremes oviparous,
0:10:39 > 0:10:41"ovum meroblastic."
0:10:41 > 0:10:45These four words, to the scientifically initiated,
0:10:45 > 0:10:47meant that the platypus laid eggs
0:10:47 > 0:10:51and that the eggs consisted of an undivided large yolk,
0:10:51 > 0:10:53just like a bird's egg.
0:10:53 > 0:10:56The mystery was, at last, solved.
0:10:59 > 0:11:03Richard Owen, who had refused to believe a mammal could lay an egg,
0:11:03 > 0:11:05was by now 80 years old
0:11:05 > 0:11:08and he was no longer held in the same esteem
0:11:08 > 0:11:10as in the early part of his career.
0:11:10 > 0:11:14The platypus had helped establish his reputation
0:11:14 > 0:11:17but now the riddle of this creature's reproduction
0:11:17 > 0:11:18had proved him wrong.
0:11:20 > 0:11:21It's extraordinary to think
0:11:21 > 0:11:24that this small animal fooled and confounded
0:11:24 > 0:11:28many of the great scientific minds of 19th century Europe.
0:11:28 > 0:11:29Not a hoax,
0:11:29 > 0:11:31but a true curiosity,
0:11:31 > 0:11:33and one like no other.
0:11:36 > 0:11:38The egg-laying platypus was hardly believable
0:11:38 > 0:11:40to Victorian researchers...
0:11:41 > 0:11:45..but evolution has thrown up many unusual mating strategies
0:11:45 > 0:11:48and, in the earlier part of the 20th century,
0:11:48 > 0:11:52the anatomy of a particular amphibian started an argument that,
0:11:52 > 0:11:54like the platypus,
0:11:54 > 0:11:56led to accusations of forgery.
0:11:56 > 0:12:00This is the curious tale of the midwife toad.
0:12:02 > 0:12:05Midwife toads are not native to Britain.
0:12:05 > 0:12:08They were introduced about a century ago and since then
0:12:08 > 0:12:10have been slowly spreading over England.
0:12:10 > 0:12:13Their natural home is Europe,
0:12:13 > 0:12:15from Germany to Spain.
0:12:15 > 0:12:22And in the 1920s, their mating habits caused a media sensation.
0:12:22 > 0:12:26Investigations into the way the body of the male toad changed
0:12:26 > 0:12:28according to its environment
0:12:28 > 0:12:31led some to believe it might be possible
0:12:31 > 0:12:34to breed a race of superhumans.
0:12:34 > 0:12:36To understand why,
0:12:36 > 0:12:39we must first know what makes the midwife toad so different
0:12:39 > 0:12:41from any other frog or toad.
0:12:43 > 0:12:46Amphibians were among the first backboned animals
0:12:46 > 0:12:47to take to the land.
0:12:47 > 0:12:50Since then, they've colonised most habitats,
0:12:50 > 0:12:54from rainforests to deserts and mountains.
0:12:55 > 0:12:57Despite spending much of their lives on land,
0:12:57 > 0:13:00most frogs and toads need water to reproduce,
0:13:00 > 0:13:04whether it be in a small vase plant or a large lake.
0:13:04 > 0:13:08But mating in water is a slippery business.
0:13:08 > 0:13:11Male toads, however, have a special adaptation.
0:13:11 > 0:13:15Black warty swellings on their wrists, called nuptial pads,
0:13:15 > 0:13:19which enable them to grip their partner securely during sex.
0:13:19 > 0:13:21Once the female produces her eggs,
0:13:21 > 0:13:23the male releases his sperm
0:13:23 > 0:13:26and then lets go. His job is done.
0:13:26 > 0:13:29But midwife toads are different.
0:13:29 > 0:13:32The male does not have nuptial pads on his wrists.
0:13:33 > 0:13:37And that's because he doesn't mate in water.
0:13:37 > 0:13:39He mates on land.
0:13:39 > 0:13:41The female produces her eggs
0:13:41 > 0:13:44and then he takes them around his legs
0:13:44 > 0:13:47with an action that has been compared
0:13:47 > 0:13:51to a man trying to put on his trousers without using his hands.
0:13:52 > 0:13:56And so it is the male toad that is the actual midwife,
0:13:56 > 0:13:58not the female.
0:13:58 > 0:14:03Midwife toads tend to live in places where open water is scarce.
0:14:04 > 0:14:06Once the male has successfully
0:14:06 > 0:14:08wrapped a string of eggs around his legs,
0:14:08 > 0:14:12he usually hides under a rock, where it's suitably damp.
0:14:18 > 0:14:21He may have as many as 150 eggs
0:14:21 > 0:14:25and he hides away for up to two months while they develop.
0:14:25 > 0:14:28Then, just before the eggs hatch,
0:14:28 > 0:14:31he sets off to find water for his emerging tadpoles.
0:14:34 > 0:14:37Now, the tadpoles of most frogs and toads
0:14:37 > 0:14:41turn into the adult form within a matter of weeks,
0:14:41 > 0:14:46but not so the midwife toad - it takes much, much longer.
0:14:46 > 0:14:50In fact, sometimes, they may even overwinter
0:14:50 > 0:14:52in the form of a tadpole,
0:14:52 > 0:14:56which is why perhaps midwife toad tadpoles are such whoppers!
0:14:58 > 0:15:02Frogs and toads are widely used in biological studies,
0:15:02 > 0:15:03because they're easy to keep
0:15:03 > 0:15:08and the different stages of their life cycles are easy to observe.
0:15:08 > 0:15:10So it's no surprise that the unusual behaviour
0:15:10 > 0:15:14of the midwife toad should attract the attention of many biologists.
0:15:16 > 0:15:19One was an Austrian scientist called Paul Kammerer,
0:15:19 > 0:15:23who worked in Vienna in the early part of the 20th century.
0:15:23 > 0:15:26And his discoveries quickly brought him great fame.
0:15:28 > 0:15:31But the toad would become a curse
0:15:31 > 0:15:34that would haunt him until the end of his life.
0:15:36 > 0:15:38Kammerer was greatly influenced
0:15:38 > 0:15:41by the great French zoologist Jean Baptiste Lamarck,
0:15:41 > 0:15:46who in 1799 published his theory that characteristics acquired
0:15:46 > 0:15:51by an animal during its life could be inherited by its offspring.
0:15:51 > 0:15:53That a giraffe, for example,
0:15:53 > 0:15:57reaching upwards to nibble the topmost shoots of trees, would
0:15:57 > 0:16:02over time lengthen its neck muscles and that this increase would then be
0:16:02 > 0:16:07inherited by its offspring, and so on, for generation after generation.
0:16:08 > 0:16:12Lamarck's theory was largely rejected after Charles Darwin
0:16:12 > 0:16:15proposed a different mechanism for evolution,
0:16:15 > 0:16:18based on changes to an animal's genetic make-up.
0:16:19 > 0:16:24Kammerer was keen to prove that Lamarck was right after all.
0:16:24 > 0:16:27But giraffes are not the ideal experimental animal,
0:16:27 > 0:16:30so he needed one he could keep in a lab and that would
0:16:30 > 0:16:34reproduce quickly, and his attention fell on the midwife toad.
0:16:35 > 0:16:37Kammerer became fascinated
0:16:37 > 0:16:41with the unusual nature of the midwife toad's reproduction.
0:16:41 > 0:16:46Why did males, like this one, carry eggs around his legs?
0:16:46 > 0:16:48And could this be changed?
0:16:48 > 0:16:51He wondered if their biology might be related
0:16:51 > 0:16:55to their unnatural environment, which is largely arid.
0:16:55 > 0:16:58Kammerer decided to see what would happen if he kept the toads
0:16:58 > 0:17:02in a warm, humid tank with access to pools of cool water.
0:17:03 > 0:17:06His work with the toads would last many years
0:17:06 > 0:17:11and involve several generations, but eventually, he noticed changes.
0:17:11 > 0:17:14Some male toads abandoned carrying the eggs
0:17:14 > 0:17:18and instead, the females laid them directly in water.
0:17:20 > 0:17:22Over several generations,
0:17:22 > 0:17:26Kammerer had managed to change the midwife toad
0:17:26 > 0:17:30from being a land-breeding animal to one that bred in water.
0:17:30 > 0:17:33But the most extraordinary discovery
0:17:33 > 0:17:36came as he continued breeding these toads.
0:17:36 > 0:17:40He noticed that the wrists of some of the males
0:17:40 > 0:17:42developed warty-looking structures,
0:17:42 > 0:17:46just like the nuptial pads of other frogs and toads, which are normally
0:17:46 > 0:17:50used by males to grip females when fertilising her eggs.
0:17:51 > 0:17:54His work suggested that somehow, by altering
0:17:54 > 0:17:58the environment in which they lived, a toad's body could be changed.
0:17:58 > 0:18:02And that change was then passed on to future generations.
0:18:04 > 0:18:07Kammerer's work was taking place at the end of the First World War
0:18:07 > 0:18:10and political movements on the left and the right
0:18:10 > 0:18:13were then keen to exploit scientific discoveries.
0:18:13 > 0:18:16Despite his subject being a small toad,
0:18:16 > 0:18:21some saw a opportunity to extend his findings beyond the laboratory.
0:18:23 > 0:18:27He was hailed as a second Darwin in the New York Times.
0:18:27 > 0:18:28Some newspapers got carried away
0:18:28 > 0:18:32and suggested that Kammerer's discoveries could apply to humans.
0:18:32 > 0:18:38His work could help, in other words, to breed a race of superhumans.
0:18:38 > 0:18:41Whether he liked it or not, Kammerer was now in the spotlight.
0:18:42 > 0:18:46He set off on a lecture tour across Europe and America.
0:18:46 > 0:18:50In Cambridge, the Professor of Zoology hailed his achievements
0:18:50 > 0:18:52and put one of Kammerer's toads on display.
0:18:54 > 0:18:56But not everyone was convinced.
0:18:56 > 0:19:00An American zoologist by the name of GK Noble wrote a damning article
0:19:00 > 0:19:03in the prestigious scientific journal Nature.
0:19:04 > 0:19:07Noble examined one of Kammerer's toads and declared that
0:19:07 > 0:19:12its black nuptial pads were fakes, produced by injecting a black dye.
0:19:13 > 0:19:15Kammerer denied this.
0:19:15 > 0:19:17Someone, he said, had interfered with his specimens
0:19:17 > 0:19:19and was trying to ruin him.
0:19:20 > 0:19:22But the damage to his name was done.
0:19:23 > 0:19:27Six weeks after the Nature article accusing him of forgery,
0:19:27 > 0:19:31Kammerer wrote a letter to another leading scientific journal.
0:19:31 > 0:19:34This is an extract of what it said.
0:19:35 > 0:19:39"On the basis of this state of affairs, I dare not -
0:19:39 > 0:19:41"although I myself have had no part
0:19:41 > 0:19:45"in these falsifications of my prior specimens -
0:19:45 > 0:19:50"any longer consider myself a proper man to accept your call.
0:19:50 > 0:19:53"I see that I am also not in a position to endure
0:19:53 > 0:19:57"this wrecking of my life's work and I hope I shall gather together
0:19:57 > 0:20:02"enough courage and strength to put an end of my wrecked life tomorrow."
0:20:03 > 0:20:06Soon after writing that letter,
0:20:06 > 0:20:10he walked into the hills around his home and shot himself.
0:20:10 > 0:20:14Whether or not Kammerer's suicide was purely down to the fallout
0:20:14 > 0:20:18from his midwife toad experiments, we can't be sure.
0:20:18 > 0:20:21There were many other problems in his personal life.
0:20:21 > 0:20:25But there can be little doubt that the scandal surrounding his work
0:20:25 > 0:20:27would've weighed heavily on his mind.
0:20:28 > 0:20:32Since Kammerer's death, a specimen of male midwife toad
0:20:32 > 0:20:36with nuptial pads has been found in the wild.
0:20:36 > 0:20:40Some scientists now believe that environmental influences
0:20:40 > 0:20:43CAN change the way some genes behave,
0:20:43 > 0:20:48and that these changes can indeed be passed on to the next generation.
0:20:48 > 0:20:53Perhaps midwife toads possess the gene to grow these structures,
0:20:53 > 0:20:56but it's only switched on in certain situations.
0:20:56 > 0:20:59Does this prove Kammerer was right?
0:20:59 > 0:21:01No-one has been able to repeat
0:21:01 > 0:21:03Kammerer's experiments with midwife toads.
0:21:03 > 0:21:07So we don't know for sure if he falsified his findings or whether
0:21:07 > 0:21:11he had stumbled upon a quirk of inheritance ahead of its time
0:21:11 > 0:21:14and beyond the understanding of scientists of his era.
0:21:14 > 0:21:17What is certain is that the nature
0:21:17 > 0:21:20of how species inherit their characteristics
0:21:20 > 0:21:24is more complex than he or others at the time originally thought.
0:21:26 > 0:21:31The curious lives of the midwife toad and the duckbilled platypus
0:21:31 > 0:21:35perplexed and wrong-footed science for some considerable time.
0:21:35 > 0:21:38But in the end, both of these creatures helped us
0:21:38 > 0:21:42to better understand the way animals evolve.