0:00:02 > 0:00:06The natural world is full of extraordinary animals
0:00:06 > 0:00:08with amazing life histories.
0:00:08 > 0:00:13Yet certain stories are more intriguing than most.
0:00:15 > 0:00:19The mysteries of a butterfly's life cycle
0:00:19 > 0:00:22or the strange biology of the Emperor Penguin.
0:00:22 > 0:00:26Some of these creatures were surrounded
0:00:26 > 0:00:30by myth and misunderstandings for a very long time,
0:00:30 > 0:00:33and some have only recently revealed their secrets.
0:00:35 > 0:00:38These are the animals that stand out from the crowd,
0:00:38 > 0:00:43the curiosities I find most fascinating of all.
0:00:50 > 0:00:53In this programme, I investigate creatures
0:00:53 > 0:00:57that have taken the ordinary and made it extraordinary.
0:00:57 > 0:01:01The chameleon that has an extra long tongue to catch prey...
0:01:02 > 0:01:07..and the giraffe with a neck so long it can reach the top of trees.
0:01:08 > 0:01:13How and why have these animals stretched nature to the limit?
0:01:13 > 0:01:15And also in this programme,
0:01:15 > 0:01:17we explore the stories of two animals
0:01:17 > 0:01:22that sent shock waves through the scientific world and beyond.
0:01:22 > 0:01:26One is a toad that became the centre of a scientific storm
0:01:26 > 0:01:31and caused accusations of fakery in the early part of the 20th century.
0:01:33 > 0:01:35The other is an Australian animal
0:01:35 > 0:01:38that baffled the greatest thinkers of Victorian Europe
0:01:38 > 0:01:42and caused many to question whether it was even real.
0:01:57 > 0:02:01The chameleon is a truly bizarre creature,
0:02:01 > 0:02:04both in its behaviour and its appearance
0:02:04 > 0:02:06unlike anything else on earth.
0:02:06 > 0:02:11So, not surprisingly, it's given rise to all kinds of legends and myths,
0:02:11 > 0:02:15This is The History Of The Four-footed Beasts by Edward Topsell
0:02:15 > 0:02:18written in the 17th century.
0:02:18 > 0:02:20And he calls the chameleon,
0:02:20 > 0:02:23"A fraudulent, ravening and gluttonous beast,
0:02:23 > 0:02:27"impure and unclean by the law of God."
0:02:27 > 0:02:31Some believed it was constructed by the devil
0:02:31 > 0:02:33from parts of other animals,
0:02:33 > 0:02:36the tail of a monkey, the skin of a crocodile,
0:02:36 > 0:02:40the tongue of a toad, the horns of a rhinoceros,
0:02:40 > 0:02:42and the eyes of who knows what.
0:02:42 > 0:02:47It was a creature sent to the world to spy for a demon master.
0:02:49 > 0:02:53When I first came face to face with the chameleon more than 50 years ago,
0:02:53 > 0:02:56I was struck not only by its beauty,
0:02:56 > 0:03:01but intrigued by its strange body, particularly by its tongue.
0:03:04 > 0:03:07The outlandish appearance of the chameleon
0:03:07 > 0:03:10made it much sought-after by curiosity hunters,
0:03:10 > 0:03:14but scientists and naturalists too were greatly puzzled
0:03:14 > 0:03:18by its extraordinary behaviour and anatomy.
0:03:20 > 0:03:23It looked and behaved like no other reptile.
0:03:25 > 0:03:30Even today, we're still discovering new things about its unique eyes,
0:03:30 > 0:03:33its astonishing tongue,
0:03:33 > 0:03:36and its ability to change its appearance.
0:03:40 > 0:03:43Chameleons are notoriously hard to find,
0:03:43 > 0:03:45partly because they move so slowly,
0:03:45 > 0:03:48but also because they match their surroundings
0:03:48 > 0:03:51in terms of colour so very well.
0:03:51 > 0:03:54This one in front of me is a dwarf chameleon
0:03:54 > 0:03:57from Natal in South Africa.
0:03:57 > 0:03:59If that's threatened by a snake,
0:03:59 > 0:04:01it doesn't bother to change its colour very much,
0:04:01 > 0:04:04because a snake's colour vision is not very good,
0:04:04 > 0:04:07but if it's threatened by a bird,
0:04:07 > 0:04:10it does camouflage itself very well indeed.
0:04:13 > 0:04:14Some species of chameleon,
0:04:14 > 0:04:18and there are 85 different species in the family,
0:04:18 > 0:04:20can even fine tune their camouflage.
0:04:23 > 0:04:25If they detect a snake approaching from below,
0:04:25 > 0:04:30they become lighter in colour and so less noticeable against the sky.
0:04:32 > 0:04:35On the other hand, if the threat comes from a bird,
0:04:35 > 0:04:38they become darker to match the background beneath them.
0:04:40 > 0:04:45A chameleon's colour is affected not only by its surroundings,
0:04:45 > 0:04:49but by the temperature and the light and its emotional state.
0:04:49 > 0:04:53Behind this screen there's a rival male.
0:04:53 > 0:04:56Let's see what happens if I remove the screen
0:04:56 > 0:04:58and let them see one another.
0:05:00 > 0:05:02This highly-coloured male is dominant
0:05:02 > 0:05:07and he immediately adds bright, aggressive colours to his display.
0:05:07 > 0:05:09The other male remains dark
0:05:09 > 0:05:12and too frightened to change colour and fight back.
0:05:12 > 0:05:15It's clear who's the boss.
0:05:20 > 0:05:23Chameleons are emotional creatures,
0:05:23 > 0:05:25darker colouration signals anger.
0:05:25 > 0:05:28This female on the right is not in the mood
0:05:28 > 0:05:32to accept the approaches of this brightly coloured and hopeful male.
0:05:41 > 0:05:44Exactly how chameleons achieve such dramatic colour changes
0:05:44 > 0:05:47greatly puzzled early naturalists.
0:05:49 > 0:05:51An Englishman named Barrow,
0:05:51 > 0:05:53who travelled in Africa in the 19th century,
0:05:53 > 0:05:57thought the changing colour was caused by something to do with air.
0:05:57 > 0:06:02He wrote, "Previous to the chameleon assuming a change in colour,
0:06:02 > 0:06:04"it makes a long inspiration,
0:06:04 > 0:06:07"the body swelling out to twice its usual size,
0:06:07 > 0:06:10"and as this inflation subsides
0:06:10 > 0:06:12"the change of colour gradually takes place."
0:06:12 > 0:06:16Well, that's an accurate observation of what happens
0:06:16 > 0:06:20when a chameleon gets angry and then it's anger subsides,
0:06:20 > 0:06:24but actually the change of colour has nothing to do with air.
0:06:24 > 0:06:29A French biologist, Mel Edwards, soon after that got it about right.
0:06:29 > 0:06:34He wrote, "There exist two layers of membranous pigment
0:06:34 > 0:06:36"placed one above the other,
0:06:36 > 0:06:41"but disposed in such a way to appear simultaneously under the cuticle
0:06:41 > 0:06:45"and sometimes in such a manner that one may hide the other."
0:06:45 > 0:06:47Which is indeed so.
0:06:49 > 0:06:53Today, we know that the chameleon's skin has three layers
0:06:53 > 0:06:58of expendable pigmented cells called chromatophores.
0:06:58 > 0:07:01They contain red, yellow, blue and white pigments
0:07:01 > 0:07:04with a deeper layer of darker melanin,
0:07:04 > 0:07:07which controls the reflection of light.
0:07:08 > 0:07:13The chameleons use colour change not only to camouflage themselves,
0:07:13 > 0:07:17but also to communicate with one another.
0:07:18 > 0:07:22Anyone who looks closely at a chameleon
0:07:22 > 0:07:26is bound to be fascinated by its eyes.
0:07:26 > 0:07:30They protrude on either side of its head
0:07:30 > 0:07:32as though they were mounted on turrets.
0:07:32 > 0:07:37And, in fact, their eyelids are fused together
0:07:37 > 0:07:42except for one tiny spot right in the middle.
0:07:42 > 0:07:45But the most extraordinary thing about them...
0:07:45 > 0:07:47is that they move independently.
0:07:47 > 0:07:52So that means the chameleon at one and the same time
0:07:52 > 0:07:55can be viewing above it and below it.
0:07:55 > 0:07:58So any insect that lands nearby
0:07:58 > 0:08:01is going to be spotted almost immediately.
0:08:03 > 0:08:10It seems that its brain receives separate messages from each eye
0:08:10 > 0:08:14and views them and receives them alternately very fast
0:08:14 > 0:08:19but independent of one another, they're not integrated.
0:08:19 > 0:08:22But the advantage of that is that it does give this
0:08:22 > 0:08:26all-round, three-dimensional view
0:08:26 > 0:08:27which is unrivalled.
0:08:30 > 0:08:34This extraordinary vision is an essential element
0:08:34 > 0:08:38in the way the chameleon uses its most astonishing feature,
0:08:38 > 0:08:41it's hugely elongated tongue.
0:08:41 > 0:08:45How this tongue worked and its construction
0:08:45 > 0:08:49greatly intrigued early naturalists - and understandably.
0:08:56 > 0:08:59This remarkable preserved specimen shows us in detail
0:08:59 > 0:09:03the impressive elongated tongue of a chameleon.
0:09:03 > 0:09:07The physical structure of the chameleon's tongue
0:09:07 > 0:09:09was easy enough to explain,
0:09:09 > 0:09:12although it proved to be a somewhat complicated organ,
0:09:12 > 0:09:17a hollow tube with a tapered cartilaginous rod at its base.
0:09:17 > 0:09:22The pad at the end was thought to be rough and sticky,
0:09:22 > 0:09:24so that it could snag its prey.
0:09:24 > 0:09:28But the mystery of how a contraption like this
0:09:28 > 0:09:31could be lengthened and projected out of the mouth
0:09:31 > 0:09:34took a little longer to fully explain.
0:09:34 > 0:09:38Perhaps the way a frigatebird inflates the balloon under its beak,
0:09:38 > 0:09:43or how a calling frog blows up its throat sac could give clues,
0:09:43 > 0:09:45both do it with air.
0:09:45 > 0:09:48Or maybe the tentacles that carry a snail's eye,
0:09:48 > 0:09:53it projects them by using its blood as an hydraulic fluid.
0:09:53 > 0:09:56But none of them fitted the bill.
0:09:57 > 0:10:00It's a much more complex process.
0:10:00 > 0:10:03The tongue is a muscular tube
0:10:03 > 0:10:06that when relaxed sits on a rod of cartilage.
0:10:06 > 0:10:09When the chameleon is ready to strike,
0:10:09 > 0:10:13muscles at the back of the tongue push it into launch position.
0:10:13 > 0:10:16When the prey is lined up and the distance calculated,
0:10:16 > 0:10:18superfast muscles contract
0:10:18 > 0:10:22and propel the tongue forward at lightning speed.
0:10:24 > 0:10:28As the tongue shoots off the end of the cartilage,
0:10:28 > 0:10:32an extra wave of energy drives it forward to its target.
0:10:33 > 0:10:36Then, like a stretched elastic band,
0:10:36 > 0:10:40its elasticity pulls it back into the chameleon's mouth.
0:10:47 > 0:10:51Recently, high-speed images revealed a new detail.
0:10:51 > 0:10:54The tip of the tongue, once thought to be sticky,
0:10:54 > 0:10:57is covered in microscopic protrusions
0:10:57 > 0:11:01that generate suction and secures its prey.
0:11:07 > 0:11:11Chameleons really are the most extraordinary creatures
0:11:11 > 0:11:15and they hold surprises for us even today.
0:11:15 > 0:11:18Only this year, a scientist working in Madagascar
0:11:18 > 0:11:23discovered a tiny little chameleon only 29mm long.
0:11:23 > 0:11:28It's the smallest known vertebrate in the world.
0:11:28 > 0:11:33It's astounding to realise that all the organs of a vertebrate's body
0:11:33 > 0:11:37could be fitted into such a tiny little creature,
0:11:37 > 0:11:40including that extraordinary tongue.
0:11:42 > 0:11:47Next, is the story of another amazing elongated structure,
0:11:47 > 0:11:51not a tongue but a neck.
0:11:54 > 0:11:58The giraffe is an animal that can't fail to impress.
0:11:58 > 0:12:01Up to 6m or 19ft in height,
0:12:01 > 0:12:05it's hugely imposing, intriguing in appearance,
0:12:05 > 0:12:08and mysterious in its biology.
0:12:08 > 0:12:12Our attraction to this unusual creatures goes back centuries.
0:12:12 > 0:12:15And one feature in particular has piqued our curiosity -
0:12:15 > 0:12:17its elongated neck.
0:12:17 > 0:12:21Such a structure seemed an impossibility of nature,
0:12:21 > 0:12:25but now we better understand the complex biology
0:12:25 > 0:12:28behind the giraffe's bizarre body.
0:12:28 > 0:12:30Our growing knowledge of this creature
0:12:30 > 0:12:34can be traced back to three very special giraffes
0:12:34 > 0:12:38and the story of a royal fascination for the exotic.
0:12:40 > 0:12:46In the 19th century, a giraffe named Zarafa, Arabic for "charming one,"
0:12:46 > 0:12:50made a big impact on Europe socially and scientifically.
0:12:50 > 0:12:56She was one of three captured in 1826 at the order of the Viceroy of Egypt,
0:12:56 > 0:12:59who wanted to use them as gifts
0:12:59 > 0:13:03to curry favour with France, Austria and England.
0:13:03 > 0:13:07Zarafa, the strongest of the three, was given to the French,
0:13:07 > 0:13:11seen here in a painting by Jacques Raymond Brascassat.
0:13:11 > 0:13:16She travelled from Egypt to Marseilles by ship.
0:13:17 > 0:13:22On reaching France, her keepers felt it was too risky to continue by boat,
0:13:22 > 0:13:28so the decision was made to walk Zarafa from Marseille in the south
0:13:28 > 0:13:30all the way to Paris,
0:13:30 > 0:13:34an overland journey of more than 550 miles.
0:13:34 > 0:13:38To some, this looked like a journey doomed to failure,
0:13:38 > 0:13:42but careful planning and the unique biology of the giraffe
0:13:42 > 0:13:44were in its favour.
0:13:44 > 0:13:48Very wisely, a forward-thinking and eminent French scientist
0:13:48 > 0:13:52called Geoffroy Saint-Hilaire was put in charge of the giraffe.
0:13:52 > 0:13:56But there was something very significant about Zarafa
0:13:56 > 0:13:59that would be key to the success of her long journey,
0:13:59 > 0:14:01it was her age.
0:14:01 > 0:14:05She was a youngster, just eight months old.
0:14:05 > 0:14:08Baby giraffes are very robust
0:14:08 > 0:14:12and can stand up and run within an hour of being born.
0:14:12 > 0:14:16They have particularly long legs in relation to their bodies,
0:14:16 > 0:14:20only half a metre shorter than those of an adult.
0:14:20 > 0:14:24Such long legs help them keep up with their mothers,
0:14:24 > 0:14:28so young Zarafa was well-equipped for walking.
0:14:33 > 0:14:36Crucial too was the fuel for Zarafa's journey.
0:14:36 > 0:14:42Young giraffe suckle for up to a year and Zarafa was bottle-fed.
0:14:42 > 0:14:47Throughout the journey, she drank up to 25 litres of milk a day,
0:14:47 > 0:14:50supplied by three milking cows.
0:14:54 > 0:14:59She marched on at a steady pace with her trusty entourage.
0:15:01 > 0:15:05After nearly 200 miles, Zarafa reached Lyon
0:15:05 > 0:15:08and Saint-Hilaire broke the walk.
0:15:08 > 0:15:10He hoped to put Zarafa onto a boat
0:15:10 > 0:15:12to go down-river for the rest of the journey.
0:15:12 > 0:15:17As they waited, 30,000 people flocked to see Zarafa.
0:15:17 > 0:15:21To the public, she was a strange and exotic creature,
0:15:21 > 0:15:24and they were intrigued why such a long neck should exist,
0:15:24 > 0:15:28and curious about how an animal could support its weight.
0:15:28 > 0:15:34In those early days, giraffe were seen as freaks, strange horned camels
0:15:34 > 0:15:37whose humps had been flattened by the stretching of their necks.
0:15:37 > 0:15:42But this was exactly what attracted Saint-Hilaire to Zarafa.
0:15:42 > 0:15:45He was fascinated by genetic exaggerations
0:15:45 > 0:15:47and how they came to be.
0:15:47 > 0:15:50Clearly, the giraffe's long neck
0:15:50 > 0:15:54enables them to feed on leaves beyond the reach of other browsers.
0:15:54 > 0:15:59But how could they physically hold up such a long neck vertically?
0:16:01 > 0:16:03DAVID LAUGHS
0:16:03 > 0:16:05Studies of giraffe anatomy
0:16:05 > 0:16:08have revealed just how the neck is supported.
0:16:08 > 0:16:14A long thick ligament like a cable runs the whole length of the neck.
0:16:14 > 0:16:18This counterbalances the weight of the head and the neck,
0:16:18 > 0:16:21and in its relaxed position, it's tight.
0:16:21 > 0:16:24So keeping the neck straight and the head up
0:16:24 > 0:16:27involves very little muscular effort.
0:16:27 > 0:16:31Bending the neck to reach down is more difficult,
0:16:31 > 0:16:34because the tough ligament has to be stretched.
0:16:35 > 0:16:39But was the ability to feed from tall trees
0:16:39 > 0:16:42the only reason for having a long neck?
0:16:42 > 0:16:46As the habits of giraffe in the wild became better known,
0:16:46 > 0:16:49people discovered that rival males
0:16:49 > 0:16:52fought one another by jousting with their necks.
0:16:52 > 0:16:55Was that the reason that they had developed long necks?
0:16:55 > 0:17:00But then someone pointed out that the females had long necks too,
0:17:00 > 0:17:02so that suggestion was discarded.
0:17:02 > 0:17:06In truth, there isn't a neat single answer,
0:17:06 > 0:17:09but access to high food, better vigilance
0:17:09 > 0:17:14and temperature regulation may all have shaped the giraffe's long neck.
0:17:16 > 0:17:21As she walked on, Zarafa continued to attract inquisitive onlookers,
0:17:21 > 0:17:25few had set eyes on such a creature, she appeared a natural impossibility.
0:17:25 > 0:17:31How could a giraffe pump the blood up such a long neck to its brain?
0:17:31 > 0:17:35And why didn't the blood rush back down into its feet?
0:17:38 > 0:17:41The giraffe's neck may be very tall,
0:17:41 > 0:17:45but, in fact, it contains exactly the same number of bones as our own,
0:17:45 > 0:17:47that is to say seven.
0:17:47 > 0:17:51But its blood pressure is twice as high as ours.
0:17:51 > 0:17:55In fact, it's higher than any other known animal.
0:17:55 > 0:17:59The pump that produces this pressure, the heart,
0:17:59 > 0:18:03surprisingly is not particularly big but it is hugely powerful.
0:18:03 > 0:18:07This is the left ventricle that has been cut through
0:18:07 > 0:18:11and you can see how thick the muscle is, getting on for about 8cm.
0:18:11 > 0:18:15This great pump produces blood,
0:18:15 > 0:18:17squirts it up the artery to the head,
0:18:17 > 0:18:22and then when it comes down through the jugular vein
0:18:22 > 0:18:24there are pocket-shaped valves
0:18:24 > 0:18:27which prevent the blood from flowing backwards into the head
0:18:27 > 0:18:31if the animal lowers its head in order to have a drink.
0:18:31 > 0:18:35Giraffes find it very awkward to drink from the ground.
0:18:35 > 0:18:37And, in fact, they rarely do so,
0:18:37 > 0:18:40they get most of their water from leaves and shoots.
0:18:40 > 0:18:44The only way to get their mouth down to the water
0:18:44 > 0:18:48is to splay their forelegs or bend them at the wrist joint.
0:18:51 > 0:18:56The giraffe, in fact, has a relatively short neck compared to its legs.
0:18:57 > 0:19:01Antelope and zebra can reach down to the ground
0:19:01 > 0:19:03without bending their legs.
0:19:03 > 0:19:06Only the giraffe and its rainforest relative the okapi
0:19:06 > 0:19:09have necks that are so short relative to their legs
0:19:09 > 0:19:12that they must splay or bend them.
0:19:13 > 0:19:16So perhaps the most remarkable feature of the giraffe
0:19:16 > 0:19:18is the length of its legs.
0:19:18 > 0:19:21They certainly were key to Zarafa's success.
0:19:21 > 0:19:25At Lyon, there was a plan to rest her legs from walking
0:19:25 > 0:19:28and to finish the journey to Paris by boat,
0:19:28 > 0:19:30but all didn't go according to plan.
0:19:31 > 0:19:34The boat didn't appear in Lyon,
0:19:34 > 0:19:37so she walked on and finally got to Paris.
0:19:37 > 0:19:40It's took her a total of 41 days
0:19:40 > 0:19:44to complete the journey of 550 miles to Paris.
0:19:44 > 0:19:48Saint-Hilaire, her trusty companion, was exhausted,
0:19:48 > 0:19:50but the giraffe was very fit.
0:19:50 > 0:19:55He wrote, "She gained weight and much more strength from the exercise.
0:19:55 > 0:19:59"Her muscles were more defined, her coat smoother and glossier
0:19:59 > 0:20:03"upon her arrival than they were in Marseille."
0:20:03 > 0:20:07Zarafa was presented to King Charles X
0:20:07 > 0:20:10and temporarily installed in a greenhouse
0:20:10 > 0:20:13in the grounds of the Jardin des Plantes.
0:20:13 > 0:20:15She was a true animal ambassador
0:20:15 > 0:20:20and 60,000 people saw her in the first three weeks in Paris.
0:20:20 > 0:20:24In the early 19th century, giraffes were a novelty
0:20:24 > 0:20:28and their biology and lives in the wild was still a mystery.
0:20:28 > 0:20:32Zarafa's success was due to a unique interplay
0:20:32 > 0:20:36of the giraffe's unusual characteristics and good timing.
0:20:36 > 0:20:40Her youth, long legs and a diet with milk
0:20:40 > 0:20:44powered her journey right across France.
0:20:46 > 0:20:49A body that was first considered bizarre
0:20:49 > 0:20:52was revealed to be perfectly evolved.
0:20:54 > 0:20:59Our story began with three giraffe that were given to Europe.
0:20:59 > 0:21:04Zarafa was the most robust of them and she lived a further 18 years.
0:21:04 > 0:21:08The Austrian lasted just a year.
0:21:08 > 0:21:13And the one sent to King George IV of England died after two.
0:21:13 > 0:21:16Saint-Hilaire learnt much from Zarafa
0:21:16 > 0:21:17and he became a key figure
0:21:17 > 0:21:21in the blossoming zoological research in France.
0:21:21 > 0:21:23The giraffe brought to England
0:21:23 > 0:21:25triggered a surge of interest in animal research
0:21:25 > 0:21:28that shifted the centre of the zoological gravity
0:21:28 > 0:21:30from France to England.
0:21:30 > 0:21:34So we can thank Zarafa for her early role
0:21:34 > 0:21:36in unravelling the biological mysteries
0:21:36 > 0:21:40of the giraffe's extraordinary body and stretched neck.
0:21:50 > 0:21:53When the first Europeans arrived in Australia,
0:21:53 > 0:21:56they were shocked by the animals they found there.
0:21:56 > 0:22:01Nothing in Europe could compare with the bizarre upright grazers
0:22:01 > 0:22:04hopping across the grassland landscape
0:22:04 > 0:22:06carrying their young in pouches.
0:22:06 > 0:22:08Kangaroos were obvious oddities,
0:22:08 > 0:22:11but another even stranger creature
0:22:11 > 0:22:13also caught the attention of early settlers.
0:22:13 > 0:22:18It lived along river banks and swam in the water.
0:22:18 > 0:22:22Those first Europeans who saw it called it a "water mole,"
0:22:22 > 0:22:25but that name didn't last long.
0:22:26 > 0:22:31Inside this box is one of the first specimens of platypus
0:22:31 > 0:22:33ever to be seen outside Australia.
0:22:40 > 0:22:44It was sent to England in 1798 by Captain John Hunter,
0:22:44 > 0:22:47the Governor of New South Wales.
0:22:47 > 0:22:51This one small animal would take the scientific world by storm
0:22:51 > 0:22:54and transform the careers and reputations
0:22:54 > 0:22:56of some of the leading thinkers of the time.
0:22:58 > 0:23:02The platypus seemed to be a concoction of different animals,
0:23:02 > 0:23:07part bird with its bill and part mammal with its furry body.
0:23:07 > 0:23:12When Charles Darwin first encountered one in the wild, it baffled even him.
0:23:12 > 0:23:16"Surely," he wrote, "two distinct creators must have been at work."
0:23:20 > 0:23:23The task of describing the first platypus specimen
0:23:23 > 0:23:25fell to naturalist George Shaw,
0:23:25 > 0:23:30who worked in the Department of Natural History in the British Museum.
0:23:30 > 0:23:32And he viewed this remarkable specimen
0:23:32 > 0:23:35with a fair degree of caution.
0:23:36 > 0:23:40This is a first edition of a journal called A Naturalist's Miscellany,
0:23:40 > 0:23:44which was published a few years after his examination,
0:23:44 > 0:23:46and it contains not only an article by him
0:23:46 > 0:23:50but a nice picture of the animal concerned.
0:23:50 > 0:23:55And at the end he says, "On a subject so extraordinary as the present,
0:23:55 > 0:23:59"a degree of scepticism is not only pardonable but laudable.
0:23:59 > 0:24:01"And I ought perhaps to acknowledge
0:24:01 > 0:24:05"that I almost doubt the testimony of my own eyes
0:24:05 > 0:24:08"with respect to the structure of this animal's beak."
0:24:08 > 0:24:11It's said that Shaw was so determined to make sure
0:24:11 > 0:24:14that he was not a victim of some elaborate hoax
0:24:14 > 0:24:16that he actually cut behind the bill
0:24:16 > 0:24:20to make sure it hand't been sewn on by some mischievous forger.
0:24:22 > 0:24:25In the late 18th century, the world was opening up,
0:24:25 > 0:24:29travellers were returning from overseas with all kinds of wonders.
0:24:29 > 0:24:34Among them were specimens of creatures that people had come to think of as being myths,
0:24:34 > 0:24:37such as mermen and mermaids.
0:24:37 > 0:24:39These were, of course, hoaxes
0:24:39 > 0:24:41put together with parts from different animals,
0:24:41 > 0:24:45so it's understandable that Shaw had doubts
0:24:45 > 0:24:48about the authenticity of his new furry specimen.
0:24:50 > 0:24:54Despite his misgivings, he decided to give it a scientific name,
0:24:54 > 0:24:57platypus, which means "flat footed."
0:24:57 > 0:25:01He didn't know however that a beetle had already been given this name
0:25:01 > 0:25:06and some years later, another taxonomist very properly gave it a new one,
0:25:06 > 0:25:10Ornithorhynchus, which means "bird snout."
0:25:10 > 0:25:15But platypus is still the name that most people use.
0:25:15 > 0:25:17But what type of creature was it?
0:25:17 > 0:25:22George Shaw believed it to be a mammal because of its furry body.
0:25:24 > 0:25:28All mammals feed on milk during the first part of their lives,
0:25:28 > 0:25:32milk that is produced by their mother's mammary glands.
0:25:32 > 0:25:36But could an animal with a large flat bill really suckle?
0:25:36 > 0:25:39Some scientists thought that was impossible,
0:25:39 > 0:25:42and anyway they couldn't believe the platypus and the monkey
0:25:42 > 0:25:45could belong to the same group of animals.
0:25:45 > 0:25:47But that view was to change.
0:25:48 > 0:25:52Some 30 years after George Shaw described the platypus,
0:25:52 > 0:25:55a German naturalist, Johann Meckel,
0:25:55 > 0:25:59produced this wonderful collection of anatomical studies.
0:25:59 > 0:26:01Meckel's meticulous and detailed work
0:26:01 > 0:26:05would help identify the true nature of this animal.
0:26:05 > 0:26:07Here...
0:26:08 > 0:26:15..we can see his drawing of a male platypus showing clearly the claw.
0:26:15 > 0:26:18Meckel also reported the existence of simple glands
0:26:18 > 0:26:21beneath the thick fur of the female platypus,
0:26:21 > 0:26:24glands that he suggested secreted milk.
0:26:24 > 0:26:28There could be little doubt that these glands produced something,
0:26:28 > 0:26:32but even then several scientists doubted Meckel's claims
0:26:32 > 0:26:34and suggested rather desperately
0:26:34 > 0:26:37that the glands secreted not milk but a lubricant.
0:26:37 > 0:26:40Today, we know that Meckel was right.
0:26:40 > 0:26:43And I was once able to use an optical probe
0:26:43 > 0:26:45to peer into a platypus' burrow
0:26:45 > 0:26:49and see a female platypus nurturing her single baby.
0:26:50 > 0:26:53Yes! And there it is, it's milk.
0:26:54 > 0:26:56Milk is the perfect food,
0:26:56 > 0:27:01it provides the growing youngster with everything it wants.
0:27:01 > 0:27:04And only mammals produce milk.
0:27:04 > 0:27:08In most mammals, of course, it comes from a nipple,
0:27:08 > 0:27:13but in this very primitive mammal it simply oozes through the skin.
0:27:14 > 0:27:19But 19th-century biologists had no such tricks to help them,
0:27:19 > 0:27:23they had to unravel the strange biology of Australian mammals
0:27:23 > 0:27:27from just a few shrivelled remains of long-dead specimens.
0:27:28 > 0:27:3140 years after their discovery of the platypus,
0:27:31 > 0:27:37a brilliant young anatomist, who was to become a giant of 19th-century science, joined the debate.
0:27:37 > 0:27:40This is a statue of Richard Owen.
0:27:40 > 0:27:43Owen was a formidable man,
0:27:43 > 0:27:46the founding Director of the Natural History Museum in Britain,
0:27:46 > 0:27:51he was once described as having so much brain as to require two hats.
0:27:51 > 0:27:56The platypus would become a central character in Owen's career.
0:27:56 > 0:27:58His work on this small creature
0:27:58 > 0:28:01would help him secure election to the prestigious Royal Society,
0:28:01 > 0:28:04an exclusive group of scientists and thinkers.
0:28:06 > 0:28:10Owen had an advantage over his European colleagues.
0:28:10 > 0:28:13Australia was a British colony
0:28:13 > 0:28:17and Owen used his contacts to supply him with specimens.
0:28:19 > 0:28:23Eventually, two baby platypuses arrived
0:28:23 > 0:28:27and it was obvious to him that they would have no difficulty in suckling.
0:28:28 > 0:28:32They had not yet developed the bill that would have made it awkward.
0:28:32 > 0:28:37So he accepted that platypus babies like other mammal babies
0:28:37 > 0:28:39were indeed raised on milk.
0:28:41 > 0:28:45But the biggest mystery of the platypus was still unsolved.
0:28:46 > 0:28:51Did this animal lay eggs just like reptiles or birds,
0:28:51 > 0:28:54or did it give birth to live young?
0:28:54 > 0:28:57Owen was at the heart of that debate.
0:28:58 > 0:29:01These jars contain the bodies of several platypus
0:29:01 > 0:29:03that were shot and sent back here to the museum
0:29:03 > 0:29:06for Richard Owen to examine.
0:29:06 > 0:29:09His determination to prove whether or not they laid eggs
0:29:09 > 0:29:13was going to cause the death of quite a number of platypus.
0:29:13 > 0:29:16The Australian aborigines were absolutely clear,
0:29:16 > 0:29:20they did lay eggs, but that was not good enough for Owen,
0:29:20 > 0:29:23he knew better then any Australian aboriginal.
0:29:23 > 0:29:26He did concede that it might be
0:29:26 > 0:29:29that the eggs were retained inside the body and hatched there
0:29:29 > 0:29:33so that the young were born live, but that's as far as he would go.
0:29:33 > 0:29:35Eggs were also sent back.
0:29:35 > 0:29:39Some of them were fake and some of them belonged to snakes.
0:29:39 > 0:29:41It was going to be some decades
0:29:41 > 0:29:45before the puzzle of the platypus was finally solved.
0:29:47 > 0:29:49The platypus now became embroiled
0:29:49 > 0:29:53in the greatest scientific debate of the Victorian era.
0:29:53 > 0:29:57Did species evolve or were they created?
0:29:57 > 0:29:59Darwin's Theory of Evolution
0:29:59 > 0:30:02suggested that species could change over time,
0:30:02 > 0:30:06so an intermediate form that laid eggs but had fur like a mammal
0:30:06 > 0:30:08was to be expected.
0:30:08 > 0:30:12But that was too much of a stretch even for Owen's great brain.
0:30:13 > 0:30:18In 1884, more than 80 years after this first platypus specimen
0:30:18 > 0:30:20had been examined by George Shaw,
0:30:20 > 0:30:26William Hay Caldwell arrived in Australia funded by a Royal Society scholarship.
0:30:26 > 0:30:31One of his main aims was to solve the platypus egg question once and for all.
0:30:31 > 0:30:33After several months in Queensland,
0:30:33 > 0:30:35and with the help of the local aborigines,
0:30:35 > 0:30:37he finally got the answer.
0:30:37 > 0:30:39He shot a female platypus
0:30:39 > 0:30:43soon after she had laid an egg in her nest burrow
0:30:43 > 0:30:46with a second egg about to emerge from her vent.
0:30:46 > 0:30:49And they looked like this.
0:30:50 > 0:30:55It was at last visible evidence that this animal did indeed lay eggs.
0:30:55 > 0:30:59He sent a telegram to a scientific gathering in Montreal,
0:30:59 > 0:31:01it was brief and to the point,
0:31:01 > 0:31:05"Monotremes oviparous, ovum meroblastic."
0:31:05 > 0:31:09These four words to the scientifically initiated
0:31:09 > 0:31:12meant that the platypus laid eggs
0:31:12 > 0:31:15and that the eggs consisted of an undivided large yolk
0:31:15 > 0:31:18just like a bird's egg.
0:31:18 > 0:31:21The mystery was at last solved.
0:31:23 > 0:31:27Richard Owen, who had refused to believe a mammal could lay an egg,
0:31:27 > 0:31:32was by now 80 years old and he was no longer held in the same esteem
0:31:32 > 0:31:35as in the early part of his career.
0:31:35 > 0:31:38The platypus had helped establish his reputation,
0:31:38 > 0:31:42but now the riddle of this creature's reproduction had proved him wrong.
0:31:44 > 0:31:47It's extraordinary to think that this small animal
0:31:47 > 0:31:52fooled and confounded many of the great scientific minds of 19th-century Europe.
0:31:52 > 0:31:57Not a hoax, but a true curiosity and one like no other.
0:32:00 > 0:32:05The egg-laying platypus was hardly believable to Victorian researchers,
0:32:05 > 0:32:09but evolution has thrown up many unusual mating strategies
0:32:09 > 0:32:12and in the early part of the 20th century,
0:32:12 > 0:32:16the anatomy of a particular amphibian started an argument
0:32:16 > 0:32:20that, like the platypus, led to accusations of forgery.
0:32:20 > 0:32:24This is the curious tale of the midwife toad.
0:32:27 > 0:32:29Midwife toads are not native to Britain,
0:32:29 > 0:32:32they were introduce about a century ago
0:32:32 > 0:32:35and since then have been slowly spreading over England.
0:32:35 > 0:32:39Their natural home is Europe, from Germany to Spain.
0:32:39 > 0:32:45And in the 1920s, their mating habits caused a media sensation.
0:32:46 > 0:32:50Investigations into the way the body of the male toad
0:32:50 > 0:32:54changed according to its environment led some to believe
0:32:54 > 0:32:58it might be possible to breed a race of superhumans.
0:32:58 > 0:33:01To understand why, we must first know
0:33:01 > 0:33:07what makes the midwife toad so different from any other frog or toad.
0:33:07 > 0:33:11Amphibians were among the first backboned animals to take to the land.
0:33:11 > 0:33:15Since then, they've colonised most habitats
0:33:15 > 0:33:19from rainforests to deserts and mountains.
0:33:19 > 0:33:22Despite spending much of their lives on land,
0:33:22 > 0:33:25most frogs and toads need water to reproduce,
0:33:25 > 0:33:28whether it be in a small vase plant or a large lake.
0:33:28 > 0:33:32But mating in water is a slippery business.
0:33:32 > 0:33:35Male toads, however, have a special adaptation,
0:33:35 > 0:33:39black warty swellings on their wrists called nuptial pads,
0:33:39 > 0:33:43which enable them to grip their partners securely during sex.
0:33:43 > 0:33:46Once the female produces her eggs,
0:33:46 > 0:33:50the male releases his sperm and then let's go, his job is done.
0:33:50 > 0:33:53But midwife toads are different,
0:33:53 > 0:33:57the male does not have nuptial pads on his wrists.
0:33:58 > 0:34:03And that's because he doesn't mate in water, he mates on land.
0:34:03 > 0:34:08The female produces her eggs and then he takes them around his legs
0:34:08 > 0:34:15with an action that's been compared to a man trying to put on his trousers without using his hands.
0:34:17 > 0:34:22So it is the male toad that is the actual midwife, not the female.
0:34:22 > 0:34:27Midwife toads tend to live in places where open water is scarce.
0:34:29 > 0:34:33Once the male has successfully wrapped a string of eggs around his legs,
0:34:33 > 0:34:37he usually hides under a rock where it's suitably damp.
0:34:42 > 0:34:46He may have as many as 150 eggs
0:34:46 > 0:34:49and he hides away for up to two months while they develop.
0:34:49 > 0:34:52Then, just before the eggs hatch,
0:34:52 > 0:34:56he sets off to find water for his emerging tadpoles.
0:34:58 > 0:35:02Now, the tadpoles of most frogs and toads
0:35:02 > 0:35:06turn into the adult form within a matter of weeks,
0:35:06 > 0:35:10but not so the midwife toad - it takes much, much longer.
0:35:10 > 0:35:16In fact, sometimes they may even overwinter in the form of a tadpole,
0:35:16 > 0:35:21which is why perhaps midwife toad tadpoles are such whoppers.
0:35:22 > 0:35:26Frogs and toads are widely used in biological studies
0:35:26 > 0:35:28because they're easy to keep
0:35:28 > 0:35:32and the different stages of their life cycles are easy to observe.
0:35:32 > 0:35:36So it's no surprise that the unusual behaviour of the midwife toad
0:35:36 > 0:35:39should attract the attention of many biologists.
0:35:40 > 0:35:43One was an Austrian scientist called Paul Kammerer,
0:35:43 > 0:35:47who worked in Vienna in the early part of the 20th century.
0:35:47 > 0:35:51And his discoveries quickly brought him great fame.
0:35:52 > 0:35:55But the toad would become a curse
0:35:55 > 0:35:58that would haunt him until the end of his life.
0:36:00 > 0:36:02Kammerer was greatly influenced
0:36:02 > 0:36:06by the great French zoologist Jean-Baptiste Lamarck,
0:36:06 > 0:36:09who, in 1799, published his theory
0:36:09 > 0:36:13that characteristics acquired by an animal during its life
0:36:13 > 0:36:16could be inherited by its offspring.
0:36:16 > 0:36:17That a giraffe, for example,
0:36:17 > 0:36:21reaching upwards to nibble the topmost shoots of trees
0:36:21 > 0:36:24would, over time, lengthen its neck muscles
0:36:24 > 0:36:28and that this increase would then be inherited by its offspring.
0:36:28 > 0:36:31And so on for generation after generation.
0:36:31 > 0:36:37Lamarck's theory was largely rejected after Charles Darwin proposed
0:36:37 > 0:36:39a different mechanism for evolution
0:36:39 > 0:36:43based on changes to an animal's genetic make-up.
0:36:43 > 0:36:48Kammerer was keen to prove that Lamarck was right after all.
0:36:48 > 0:36:51But giraffes are not the ideal experimental animal,
0:36:51 > 0:36:56so he needed one he could keep in a lab and that would reproduce quickly.
0:36:56 > 0:36:59And his attention fell on the midwife toad.
0:36:59 > 0:37:01Kammerer became fascinated
0:37:01 > 0:37:05with the unusual nature of the midwife toad's reproduction.
0:37:05 > 0:37:08Why did males like this one
0:37:08 > 0:37:12carry eggs around his legs and could this be changed?
0:37:12 > 0:37:18He wondered if their biology might be related to their natural environment, which is largely arid.
0:37:18 > 0:37:22Kammerer decided to see what would happen
0:37:22 > 0:37:24if he kept the toads in a warm, humid tank
0:37:24 > 0:37:27with access to pools of cool water.
0:37:27 > 0:37:30His work with the toads would last many years
0:37:30 > 0:37:34and involve several generations, but eventually he noticed changes.
0:37:34 > 0:37:38Some male toads abandoned carrying the eggs
0:37:38 > 0:37:42and instead the females laid them directly in water.
0:37:44 > 0:37:50Over several generations, Kammerer had managed to change the midwife toad
0:37:50 > 0:37:55from being a land-breeding animal to one that bred in water.
0:37:55 > 0:38:00But the most extraordinary discovery came as he continued breeding these toads.
0:38:00 > 0:38:04He noticed that the wrists of some of the males
0:38:04 > 0:38:06developed warty-looking structures
0:38:06 > 0:38:09just like the nuptial pads of other frogs and toads
0:38:09 > 0:38:12which are normally used by males
0:38:12 > 0:38:15to grip females when fertilising her eggs.
0:38:15 > 0:38:17His work suggested that somehow,
0:38:17 > 0:38:20by altering the environment in which they lived,
0:38:20 > 0:38:22a toad's body could be changed
0:38:22 > 0:38:27and that change was then passed on to future generations.
0:38:27 > 0:38:32Kammerer's work was taking place at the end of the First World War
0:38:32 > 0:38:34and political movements on the left and the right
0:38:34 > 0:38:38were then keen to exploit scientific discoveries.
0:38:38 > 0:38:41Despite his subject being a small toad,
0:38:41 > 0:38:46some saw an opportunity to extend his findings beyond the laboratory.
0:38:47 > 0:38:51He was hailed as a second Darwin in the New York Times.
0:38:51 > 0:38:53Some newspapers got carried away
0:38:53 > 0:38:56and suggested that Kammerer's discoveries could apply to humans.
0:38:56 > 0:39:02His work could help, in other words, to breed a race of superhumans.
0:39:02 > 0:39:06Whether he liked it or not, Kammerer was now in the spotlight.
0:39:06 > 0:39:11He set off on a lecture tour across Europe and America.
0:39:11 > 0:39:14In Cambridge, the Professor of Zoology hailed his achievements
0:39:14 > 0:39:17and put one of Kammerer's toads on display.
0:39:17 > 0:39:20But not everyone was convinced.
0:39:20 > 0:39:24An American zoologist by the name of GK Noble wrote a damning article
0:39:24 > 0:39:28in the prestigious scientific journal Nature.
0:39:28 > 0:39:31Noble examined one of Kammerer's toad
0:39:31 > 0:39:34and declared that its black nuptial pads were fakes,
0:39:34 > 0:39:36produced by injecting a black dye.
0:39:38 > 0:39:42Kammerer denied this. Someone, he said, had interfered with his specimens
0:39:42 > 0:39:44and was trying to ruin him.
0:39:44 > 0:39:48But the damage to his name was done.
0:39:48 > 0:39:51Six weeks after the Nature article accusing him of forgery,
0:39:51 > 0:39:55Kammerer wrote a letter to another leading scientific journal.
0:39:55 > 0:39:58This is an extract of what it said.
0:40:00 > 0:40:02"On the basis of this state of affairs,
0:40:02 > 0:40:09"I dare not, although I myself have no part in these falsifications of my prior specimens,
0:40:09 > 0:40:14"any longer consider myself a proper man to accept your call.
0:40:14 > 0:40:20"I see that I'm also not in a position to endure this wrecking of my life's work,
0:40:20 > 0:40:23"and I hope I shall gather together enough courage and strength
0:40:23 > 0:40:26"to put an end of my wrecked life tomorrow."
0:40:28 > 0:40:30Soon after writing that letter,
0:40:30 > 0:40:35he walked into the hills around his home and shot himself.
0:40:35 > 0:40:37Whether or not Kammerer's suicide
0:40:37 > 0:40:42was purely down to the fallout from his midwife-toad experiments, we can't be sure -
0:40:42 > 0:40:45there were many other problems in his personal life -
0:40:45 > 0:40:49but there can be little doubt that the scandal surrounding his work
0:40:49 > 0:40:52would have weighed heavily on his mind.
0:40:52 > 0:40:57Since Kammerer's death, a specimen of male midwife toad
0:40:57 > 0:41:00WITH nuptial pads has been found in the wild.
0:41:00 > 0:41:02Some scientists now believe
0:41:02 > 0:41:07that environmental influences can change the way some genes behave
0:41:07 > 0:41:12and that these changes can indeed be passed on to the next generation.
0:41:12 > 0:41:16Perhaps midwife toads possess the gene to grow these structures,
0:41:16 > 0:41:20but it's only switched on in certain situations.
0:41:20 > 0:41:23Does this prove Kammerer was right?
0:41:23 > 0:41:27No-one has been able to repeat Kammerer's experiments with midwife toads,
0:41:27 > 0:41:30so we don't know for sure if he falsified his findings,
0:41:30 > 0:41:35or whether he had stumbled upon a quirk of inheritance ahead of its time
0:41:35 > 0:41:38and beyond the understanding of scientists of his era.
0:41:38 > 0:41:44What is certain is that the nature of how species inherit their characteristics
0:41:44 > 0:41:49is more complex than he or others at the time originally thought.
0:41:51 > 0:41:55The curious lives of the midwife toad and the duck-billed platypus
0:41:55 > 0:41:59perplexed and wrong-footed science for some considerable time.
0:41:59 > 0:42:02But in the end, both these creatures
0:42:02 > 0:42:07helped us to better understand the way animals evolve.