0:00:04 > 0:00:07We have an extraordinary relationship with dogs.
0:00:07 > 0:00:11We love them like no other animal on the planet.
0:00:11 > 0:00:14What makes our relationship so special, is perhaps the dog's
0:00:14 > 0:00:18ability to be able to read our emotions so effectively.
0:00:18 > 0:00:22They've been around longer than any other pet.
0:00:22 > 0:00:25There are now eight million dogs living in the UK alone.
0:00:27 > 0:00:29The dogs are wonderful.
0:00:29 > 0:00:34We've got over 400 breeds across the world and every one of them has something special about them.
0:00:37 > 0:00:43But only now are we beginning to realise just how important that relationship could be.
0:00:46 > 0:00:49New research is revealing ever more
0:00:49 > 0:00:53intricate connections between human and dog.
0:00:53 > 0:00:58Without that initial starting phase of dog domestication, civilisation just would not have been possible.
0:01:01 > 0:01:05So why do we love an animal that was once a fearsome predator?
0:01:07 > 0:01:12TRANSLATION: This fire-breathing dragon has turned into a human friend.
0:01:12 > 0:01:16Could they in some ways be more intelligent than even our closest relative?
0:01:16 > 0:01:19Suddenly, there were dogs doing something that not even chimps could do.
0:01:19 > 0:01:25And in the future, what impact might dogs have on all our lives?
0:01:25 > 0:01:29They're going to help us tackle some of the most dangerous diseases of
0:01:29 > 0:01:33our time, diseases that are killing millions of people every year.
0:01:50 > 0:01:52Corrie!
0:01:52 > 0:01:59- Come here.- Every owner will spend an average of £20,000 on their beloved dog in its lifetime.- Good boy. Sit.
0:01:59 > 0:02:03We treat them as if they are fellow human beings
0:02:03 > 0:02:06with all the thoughts, feelings and emotions of a family member.
0:02:06 > 0:02:10- Good girl.- It's an incredibly close relationship.
0:02:10 > 0:02:15We share our lives, our homes, even our beds with them.
0:02:15 > 0:02:18- We're very close. We're best friends.- Pippin sleeps with us.
0:02:18 > 0:02:22He loves being in the bed with his head on the pillow.
0:02:22 > 0:02:25He just seems to fit in with
0:02:25 > 0:02:29- your lifestyle.- She's there with my slippers first thing in the morning.
0:02:29 > 0:02:32She's part of the family, she IS the family.
0:02:39 > 0:02:45For decades, science has dismissed dogs as being unworthy of legitimate study.
0:02:48 > 0:02:50But all that has changed.
0:02:50 > 0:02:55Scientists are now attempting to understand dogs like never before.
0:02:55 > 0:02:59How deep is the bond between us?
0:02:59 > 0:03:06Where did this relationship come from? And ultimately, why is it dogs that are man's best friend?
0:03:06 > 0:03:08Dogs are all over the world, they're everywhere.
0:03:08 > 0:03:11Anywhere you find humans, you will almost certainly find dogs.
0:03:11 > 0:03:15We're now beginning to realise that we can answer certain questions
0:03:15 > 0:03:17in dogs that we can't really answer in any other species.
0:03:17 > 0:03:20There's been this explosion in dog research, I think,
0:03:20 > 0:03:27because they are specially tuned into humans and this makes dogs extremely interesting as a model.
0:03:34 > 0:03:40Here at the University of Lincoln, Professor Daniel Mills is fascinated by dogs.
0:03:40 > 0:03:47Using state-of-the-art technology, he wants to find evidence of how close our relationship really is.
0:03:47 > 0:03:53What we're trying to do here is see the world from a dog's perspective rather than just impose our own
0:03:53 > 0:03:56views as to how we think the dog sees the world.
0:03:56 > 0:04:02He's attempting to discover if dogs are as good at reading our emotions as their owners claim.
0:04:03 > 0:04:07He'll know what I'm thinking even before it's turned into a thought bubble.
0:04:07 > 0:04:12He is clearly an animal, I accept that he is totally an animal.
0:04:12 > 0:04:18I am not under any illusions that he isn't but he's more knowing than I would expect an animal to be.
0:04:18 > 0:04:24He will look at me with sorrowful eyes and then give me one big lick on the hand as if to say it's all right.
0:04:24 > 0:04:26It's this sixth sense that dogs have.
0:04:29 > 0:04:33One of the things that a lot of people comment on
0:04:33 > 0:04:37is that dogs seem to be naturally attuned to them and be able to sense their moods and whatever.
0:04:37 > 0:04:41Part of our work here is to look into the scientific basis of that.
0:04:43 > 0:04:51The key to a dog's ability to read our emotions might lie in something we all do without knowing it.
0:04:51 > 0:04:55When we express our emotions in our faces, we don't do it symmetrically.
0:04:55 > 0:04:59It's been shown that if you take somebody's face when they're expressing some emotion like
0:04:59 > 0:05:05happiness or anger or something like that, there is a difference between the left and right side.
0:05:05 > 0:05:10Composite faces consisting of two right or two left sides look very different.
0:05:12 > 0:05:14One theory is maybe our emotions
0:05:14 > 0:05:20are more faithfully presented in the right side of our face, and that's the side that we tune into.
0:05:20 > 0:05:22When we look at a face, we have what's known as a natural
0:05:22 > 0:05:29left gaze bias so you naturally look much more towards the left, ie the right-hand side of somebody's face.
0:05:31 > 0:05:34Eye tracking software has demonstrated that
0:05:34 > 0:05:39when presented with a human face, we nearly always look left first.
0:05:39 > 0:05:45Daniel Mills wanted to find out if dogs used the same trick to read human faces.
0:05:45 > 0:05:48Shifting the direction of your gaze we thought
0:05:48 > 0:05:51thought was fairly unique to people until we started looking at dogs.
0:05:51 > 0:05:55Tess, Tessy!
0:05:55 > 0:06:00To test the theory, his team recreated this experiment with dogs.
0:06:00 > 0:06:05- Bruce, what's that?- They presented a series of images showing human faces,
0:06:05 > 0:06:11dog faces and inanimate objects and recorded the direction of a dog's gaze with a video camera.
0:06:11 > 0:06:18We found that dogs when they are looking at pictures of dog faces
0:06:18 > 0:06:22or objects, they will look randomly on the left or the right.
0:06:22 > 0:06:27But when it came to human faces, they made a remarkable discovery.
0:06:28 > 0:06:34So now we have Tess looking at a human face so first she's looking in the middle of the screen.
0:06:34 > 0:06:38Here is the first eye movements on the left.
0:06:38 > 0:06:45She's in the middle and she's going on the left, and then the dog is going to be even more on the left.
0:06:45 > 0:06:52So now this is Moose and then we can see really well that this is a left gaze.
0:06:52 > 0:06:54From here to here.
0:06:54 > 0:06:57We can see the white here.
0:06:57 > 0:07:00She's even moving her head.
0:07:04 > 0:07:10As far as we know, no other animal has this relationship with the human face.
0:07:10 > 0:07:13Dogs don't do this with each other.
0:07:13 > 0:07:20Incredibly, it seems they've acquired a new skill to enable them to read our emotions.
0:07:20 > 0:07:24Being able to detect when somebody is angry or potentially harmful,
0:07:24 > 0:07:28you could understand that there may be a biological advantage in being able to read people's emotions.
0:07:28 > 0:07:32Equally, it makes sense for a dog to approach somebody when they're smiling.
0:07:34 > 0:07:39If dogs can read human emotion, and increasingly the scientific evidence is beginning
0:07:39 > 0:07:45to point in that direction, that's going to form the basis of a very powerful bond between human and dog.
0:07:45 > 0:07:48Evidence like this appears to underpin our conviction
0:07:48 > 0:07:52that dogs understand us in a way that other animals cannot.
0:07:53 > 0:08:00But for many dog owners, this unique relationship is much more than a one-way street.
0:08:00 > 0:08:02I like to think we understand him.
0:08:02 > 0:08:05Yes, but he woofs and we talk.
0:08:05 > 0:08:08That's because he wants to be part of the conversation.
0:08:08 > 0:08:11If he's bored, he'll take a deep sigh and go...
0:08:11 > 0:08:13SHE WHINES LIKE DOG
0:08:13 > 0:08:15He's got a bark when he wants to go out and he's got a bark...
0:08:15 > 0:08:18SHE WOOFS
0:08:18 > 0:08:21And a bark when he hears strange noises.
0:08:21 > 0:08:24Sometimes when he tells the kittens off, he goes...
0:08:24 > 0:08:26like that. SHE WOOFS
0:08:26 > 0:08:30If you're in a certain mindset, you can almost understand what they're thinking.
0:08:34 > 0:08:41The idea that we can understand barking almost like a language has always been dismissed by scientists.
0:08:41 > 0:08:47But in Hungary, they are trying to see if there's any evidence to back up the claims made by dog owners.
0:08:47 > 0:08:49Here, at Eotvos Lorand University in Budapest,
0:08:49 > 0:08:57is the world's first research facility dedicated to investigating the human/dog relationship.
0:08:57 > 0:09:02Dr Adam Miklosi wants to see if we humans really can understand dogs' barks.
0:09:04 > 0:09:09Today, he's out on a field expedition collecting recordings.
0:09:10 > 0:09:18Scientists used to think that barking is a random noise without any specific information or content.
0:09:18 > 0:09:20However, we have a different idea.
0:09:20 > 0:09:27Dogs might tell us something about their emotions, anger, fear, happiness, despair.
0:09:27 > 0:09:34These are basic emotions which I think humans might be able to recognise in the barking sound.
0:09:34 > 0:09:37To test this idea, Adam and his team acted out
0:09:37 > 0:09:42a number of scenarios, provoking dogs to bark in different ways.
0:09:42 > 0:09:49But when the recordings are played back to people, will they be able to match the bark to the emotion?
0:09:49 > 0:09:51Alone bark.
0:10:02 > 0:10:04THE DOG BARKS
0:10:04 > 0:10:05That sounds like a dog asking for attention.
0:10:08 > 0:10:11- It's anxious.- It's sad.
0:10:11 > 0:10:13Distressed.
0:10:13 > 0:10:17Want to be let off a chain or something like that.
0:10:17 > 0:10:22THE DOG BARKS
0:10:22 > 0:10:26- I think that one's playful. - Excitement.
0:10:27 > 0:10:32It seems as though they're actually asking their owner for something.
0:10:32 > 0:10:36It sounds as if it may want a ball or a toy or something.
0:10:36 > 0:10:38She could be playing with it.
0:10:41 > 0:10:43THE DOG BARKS
0:10:48 > 0:10:49Angry.
0:10:51 > 0:10:56This is a sound that she would make if she saw somebody behind the fence walking along.
0:10:58 > 0:11:01it's a stranger encroaching on territory.
0:11:05 > 0:11:08The results of Miklosi's research are remarkable.
0:11:08 > 0:11:14It's proved there's incredibly strong agreement between people about what different barks mean.
0:11:14 > 0:11:18'Overall in the study, you could see that people can discriminate'
0:11:18 > 0:11:23six barks and most of them were quite successful in this.
0:11:23 > 0:11:27Dr Miklosi has developed a system to analyse the barks.
0:11:27 > 0:11:30It's helped him decode how dogs communicate meaning.
0:11:32 > 0:11:35I measure the three features of this sound.
0:11:35 > 0:11:42One was the frequency, the other was the tonality and the third was the interval between the barking sounds.
0:11:42 > 0:11:46Probably, this is also what the judgment of people is
0:11:46 > 0:11:50based when they are describing the bark in terms of emotional content.
0:11:52 > 0:11:59But what's more surprising is not our ability to interpret the barks, but what it reveals about dogs.
0:11:59 > 0:12:04In the natural world, dogs' wild relatives don't really bark.
0:12:04 > 0:12:09Amazingly, it seems that during the course of domestication, dogs may have evolved
0:12:09 > 0:12:14their elaborate vocal repertoire especially to communicate with us.
0:12:14 > 0:12:18'At the basic level, everyone can do it and there is a good chance that'
0:12:18 > 0:12:22barking is a very good means to communicate with humans.
0:12:25 > 0:12:30The evidence from these recent experiments seems to confirm what dog owners have asserted all along,
0:12:30 > 0:12:35that we're incredibly attuned to each other in a way that no other two species are.
0:12:38 > 0:12:44But new research has uncovered that the bond between humans and dogs may be even deeper.
0:12:51 > 0:12:57Research has turned to the most powerful bond, that between mother and baby, for clues.
0:13:06 > 0:13:08It's really hard to describe.
0:13:08 > 0:13:11It's just an amazing feeling.
0:13:11 > 0:13:16In Sweden, Professor Kerstin Uvnas-Moberg has been studying the role
0:13:16 > 0:13:20of the hormone oxytocin in bonding mothers with their newborn babies.
0:13:23 > 0:13:27Oxytocin is a little, little heptide hormone.
0:13:27 > 0:13:29It's just nine amino acids.
0:13:29 > 0:13:34It's produced in a very old part of the brain called the hypothalamus
0:13:34 > 0:13:42and oxytocin helps the mother quickly establish the positive feelings and the bond to the baby.
0:13:42 > 0:13:49Each time a mother breast feeds, she has a new release of oxytocin and this reinforces the bond.
0:13:51 > 0:13:53It's sort of in a way
0:13:53 > 0:13:58difficult to understand how you can be familiar with somebody
0:13:58 > 0:14:02- who is actually a stranger so quickly, don't you think?- Yes.
0:14:10 > 0:14:18Professor Uvnas-Moberg believes oxytocin plays a similar role in the bond between dogs and their owners.
0:14:20 > 0:14:22A lot of people would say, "Oh, it's not possible, dogs and humans, we're not the same.
0:14:22 > 0:14:26"dogs and humans, it's very, very different."
0:14:26 > 0:14:32But I would say that people who have dogs, who are used to animals and used to interaction with animals,
0:14:32 > 0:14:35they would say, "Oh, that's not so strange."
0:14:35 > 0:14:39To test the theory, blood samples were taken
0:14:39 > 0:14:44from dogs and their owners before and during a petting session.
0:14:45 > 0:14:48'We had a basal blood sample and there was nothing and then we
0:14:48 > 0:14:52'had the sample taken at one minute and three minutes.'
0:14:52 > 0:14:56You could see this beautiful peak of oxytocin.
0:14:56 > 0:15:00'The fascinating thing is that the peak of oxytocin is similar'
0:15:00 > 0:15:03to the one we see in breast feeding mothers.
0:15:03 > 0:15:07Surprisingly, it's not just the owners who are affected.
0:15:07 > 0:15:13Blood samples taken from dogs reveal a similar burst of oxytocin.
0:15:13 > 0:15:16It is a mutual kind of interaction, you know.
0:15:16 > 0:15:20The owner touches with her hands and they both smell,
0:15:20 > 0:15:28hear and see each other. That is a very nice way of triggering oxytocin release in the two of them.
0:15:31 > 0:15:33Oxytocin has a powerful physiological effect.
0:15:33 > 0:15:39It lowers the heart rate and blood pressure, leading to reduced levels of stress.
0:15:42 > 0:15:47Research indicates that owning a dog could even extend your life.
0:15:48 > 0:15:50If you have a dog,
0:15:50 > 0:15:56you are much less likely to have a heart attack and if you have a heart attack, you are three to four
0:15:56 > 0:16:01times more likely to survive it if you have a dog than if you don't.
0:16:16 > 0:16:19So where does this incredible relationship come from?
0:16:19 > 0:16:22When did it start and how?
0:16:22 > 0:16:26It's a question that has puzzled scientists ever since Darwin.
0:16:26 > 0:16:32He recognised the special relationship we have with dogs but was at a loss to explain it.
0:16:32 > 0:16:38Darwin couldn't even say for sure which animal was the true ancestor of the dog.
0:16:38 > 0:16:42It's a complex puzzle that both archaeologists
0:16:42 > 0:16:46and molecular geneticists have been working to solve.
0:16:46 > 0:16:48There's a huge amount of variation in present-day dogs.
0:16:48 > 0:16:53Consider the difference between a Pekinese and a Great Dane.
0:16:53 > 0:16:59Could they really all be descended from one wild ancestor?
0:16:59 > 0:17:04It could have been a coyote that might have intergressed with a wolf and then that may
0:17:04 > 0:17:11have been slightly selected upon to create one particular breed of dog, or jackals or African wild dogs.
0:17:11 > 0:17:13Any number of these other dog-like species that are out there
0:17:13 > 0:17:18must have come together and that's where that variation must have come.
0:17:18 > 0:17:24Until the advent of molecular genetics, archaeology had few firm answers.
0:17:24 > 0:17:29All you have to play with are the bones and so when you look at the bones, if you don't have
0:17:29 > 0:17:36a very small flat-faced round-headed pug in the archaeological record, you don't know where that came from.
0:17:36 > 0:17:39Those are questions that before genetics you really couldn't answer.
0:17:40 > 0:17:43To unravel the evolutionary origins of dogs, molecular
0:17:43 > 0:17:49geneticists compared DNA from dogs with that of their wild relatives.
0:17:50 > 0:17:54Specifically, they looked at mitochondrial DNA sequences
0:17:54 > 0:17:58which are passed unchanged down the maternal line.
0:17:58 > 0:18:04What's so useful for scientists is that mitochondrial DNA changes little over time
0:18:04 > 0:18:09and so acts as a kind of signature left by an animal's ancestors.
0:18:10 > 0:18:13Those markers in domestic dogs show them to be much more
0:18:13 > 0:18:17closely related to grey wolves than they are to any other species.
0:18:17 > 0:18:20There's no admixture so we never see a mitochondrial signature of
0:18:20 > 0:18:24an African wild dog, jackal or coyote in a domestic dog.
0:18:24 > 0:18:27Thousands upon thousands of mitochondrial DNA that has been
0:18:27 > 0:18:31extracted from domestic dogs, every single one of them just looks just like a grey wolf.
0:18:33 > 0:18:38It's now without doubt that dogs are domesticated wolves,
0:18:38 > 0:18:41but how and when did it happen?
0:18:41 > 0:18:46- Again, the archaeological record is inconclusive.- What is clearly a dog?
0:18:46 > 0:18:50Clearly, a dog is something which is clearly not a wolf.
0:18:50 > 0:18:59Well, here's a wolf skull and as you can see it's a long, quite low skull with a relatively flat top.
0:18:59 > 0:19:02The teeth are quite large and the thing is quite narrow.
0:19:02 > 0:19:05Compare that with a domestic dog.
0:19:05 > 0:19:08This is a cairn terrier and as you can see,
0:19:08 > 0:19:11the process of domestication has gone really quite a long way.
0:19:11 > 0:19:16The whole face is very much shorter, it's been contracted towards the brain case.
0:19:16 > 0:19:21The brain case itself has a much steeper front and a much more bowed upper surface.
0:19:21 > 0:19:24If you found that, you would be in no doubt you were dealing with a domestic dog.
0:19:24 > 0:19:31But this is a domestic Alsatian and telling these apart really would be substantially difficult.
0:19:32 > 0:19:37And since early dogs were probably very wolf-like, it's hard to pinpoint
0:19:37 > 0:19:42when domestication happened by looking at the shape of the bones.
0:19:42 > 0:19:47The best I can give you is around 12 or 13,000 years ago.
0:19:47 > 0:19:51We start seeing the first things that everybody would accept as being domestic dogs.
0:19:51 > 0:19:55But mitochondrial DNA offered a different set of clues.
0:19:55 > 0:19:59The original genetic data that were coming out seemed to suggest that domestication was happening on
0:19:59 > 0:20:04a far earlier timescale than was suggested by anything in the archaeological record.
0:20:04 > 0:20:08The first dates that were coming out were on the order of 100,000
0:20:08 > 0:20:13years or more, which a lot of archaeologists raised their eyebrows at.
0:20:13 > 0:20:17It's hotly debated exactly when dogs were domesticated,
0:20:17 > 0:20:21but there's one thing archaeologists and geneticists agree on:
0:20:21 > 0:20:27our relationship with dogs goes back thousands of years further than with any other pet.
0:20:30 > 0:20:34It was a time when we were still hunter-gatherers.
0:20:35 > 0:20:41Dogs were certainly the first animal to be domesticated, and they fit into hunting and
0:20:41 > 0:20:46gathering societies probably better than any other species out there.
0:20:46 > 0:20:50At this stage when we're hunting and gathering and killing wild animals,
0:20:50 > 0:20:54after you finish with them you're creating a relatively large pile
0:20:54 > 0:20:58of bone and leftover meat, things that these wolves would have been very attracted to.
0:20:58 > 0:21:04Those wolves that were able to take advantage of that resource, and were a little bit less afraid and could
0:21:04 > 0:21:09approach the human camp, were then setting themselves up into a closer relationship with humans.
0:21:11 > 0:21:12We are carnivores,
0:21:12 > 0:21:18we are social carnivores, we hunt in groups and we hunt in daylight.
0:21:18 > 0:21:21There are not many other species that do that.
0:21:21 > 0:21:26The wolf is a social carnivore that hunts by daylight, and therefore,
0:21:26 > 0:21:30there's natural potential for teamwork between those two species.
0:21:34 > 0:21:37We became much better hunters with dogs.
0:21:37 > 0:21:42We are more successfully taking down large game, which means we have more food to eat, which means we can have
0:21:42 > 0:21:45more offspring, which means the overall populations of humans grow.
0:21:48 > 0:21:55Dog domestication may have helped pave the way for a fundamental change in human lifestyle.
0:21:55 > 0:22:01It's hard to see how early herders would have moved and protected
0:22:01 > 0:22:05and guarded their flocks without domestic dogs being in place.
0:22:05 > 0:22:08And one has to wonder whether agriculture would ever really have
0:22:08 > 0:22:12made it as a viable alternative to hunting and gathering.
0:22:15 > 0:22:21Some believe that the influence of dogs on our development was not just important, but pivotal.
0:22:21 > 0:22:23Dogs absolutely turn the tables.
0:22:23 > 0:22:27Without dogs, humans would still be hunter gatherers.
0:22:27 > 0:22:30And without that initial starting phase of dog domestication,
0:22:30 > 0:22:32civilisation would not have been possible.
0:22:49 > 0:22:53We look at our dogs and we see an intelligence,
0:22:53 > 0:22:58an ability to interact with us unlike any other domesticated animal.
0:22:58 > 0:23:02But are dogs really that clever, or are they just dumb animals taught
0:23:02 > 0:23:06to perform tricks that mimic human behaviour?
0:23:06 > 0:23:10I think she's very smart. She learns tricks fairly quickly.
0:23:10 > 0:23:13If I am packing a suitcase, they will go and sit in
0:23:13 > 0:23:17the suitcase because they know that suitcase is going to go somewhere.
0:23:17 > 0:23:20When I'm talking to him most of the time,
0:23:20 > 0:23:25his little head usually jilts to the side as if he knows what I'm saying.
0:23:25 > 0:23:29I do talk to her and she picks up on what I say to her.
0:23:29 > 0:23:32I know it sounds stupid, but I do have a conversation with my dog.
0:23:38 > 0:23:42But how does the intelligence of a dog really compare in the animal kingdom?
0:23:42 > 0:23:47New research is discovering that in certain ways, dogs may actually think
0:23:47 > 0:23:53more like us than any other animal, including our nearest relative, the chimpanzee.
0:23:55 > 0:23:58Of all the questions around the evolution of human cognition,
0:23:58 > 0:24:01of course, people would focus in on chimps quite naturally.
0:24:01 > 0:24:05Suddenly, there were dogs doing something not even chimps could do.
0:24:06 > 0:24:09Cognitive psychologist Juliane Kaminski from
0:24:09 > 0:24:17the Max Planck Institute in Germany, has been comparing chimps with dogs in a series of revealing experiments.
0:24:26 > 0:24:30At Leipzig Zoo, Juliane is testing chimps to see if they can understand
0:24:30 > 0:24:35human gestures, like pointing, to find a hidden treat.
0:24:44 > 0:24:50As simple as it seems to us, even our nearest primate relatives failed the task miserably.
0:24:50 > 0:24:55She's not really focusing on me and she's simply making her own choice.
0:24:55 > 0:25:00Most of the time you can see that she makes a decision long before I give my gesture.
0:25:00 > 0:25:03She doesn't even wait for my information.
0:25:03 > 0:25:09It's such an uncooperative attraction, so it's like really I'm providing information for her to
0:25:09 > 0:25:15find food, which is just simply something which would never happen in a chimp group, really.
0:25:15 > 0:25:17A chimp wouldn't go like, "Oh, look there's the banana",
0:25:17 > 0:25:19and then another chimp could go and get it.
0:25:24 > 0:25:27Since we're the only species that makes this gesture,
0:25:27 > 0:25:30it would be remarkable if any animal could understand it.
0:25:34 > 0:25:39But dog owners take it for granted that their dogs respond to pointing.
0:25:39 > 0:25:40Good boy!
0:25:40 > 0:25:46For Kaminski, it's proof of their extraordinary social intelligence.
0:25:46 > 0:25:50If you really look at that gesture, it's an informative gesture.
0:25:50 > 0:25:52So it's in its essence a very cooperative
0:25:52 > 0:25:55interaction, so I'm really helping you to find something.
0:25:55 > 0:26:02And for dogs, following, pointing seems to be very natural, and it makes dogs extremely interesting.
0:26:02 > 0:26:06In fact, dogs are so tuned into our social cues,
0:26:06 > 0:26:10they can even pick up on something as subtle as the direction of our gaze.
0:26:18 > 0:26:24Humans have unique almond-shaped eyes with exposed white sclera visible on each side.
0:26:24 > 0:26:30One hypothesis is that we have evolved those eyes because we use it for communication.
0:26:30 > 0:26:35With human eyes you can really tell easily which direction I'm looking.
0:26:35 > 0:26:38We think that maybe dogs are really tuned into that,
0:26:38 > 0:26:41and really are interested in human eyes because of that.
0:26:41 > 0:26:45But these aren't skills that dogs use with each other.
0:26:45 > 0:26:49They are abilities dogs only use with humans.
0:26:49 > 0:26:54I think it's very, very easy to imagine that they develop special skills in
0:26:54 > 0:26:57interacting with humans, because that's their new social partner.
0:26:57 > 0:27:03So they kind of learn to interpret human communication, which is different from dog communication.
0:27:03 > 0:27:08So they kind of learned a second language, so you could probably say they are bilingual, yes.
0:27:12 > 0:27:18Even puppies as young as six weeks old seem to intelligently respond to human gestures.
0:27:20 > 0:27:23At least some of the time!
0:27:25 > 0:27:29The fact they're quite young puppies can do something,
0:27:29 > 0:27:33if they learn it, they learn it very quickly, and it's obviously that
0:27:33 > 0:27:40they are ready to do it - so from the very beginning they are ready to receive human communication.
0:27:44 > 0:27:48As dog owners, we think we understand the limits of our dogs' intelligence.
0:27:48 > 0:27:52But now some dogs are challenging our assumptions.
0:27:52 > 0:27:55We may have to reconsider how clever dogs are.
0:27:55 > 0:28:01Juliane Kaminski has discovered a remarkable dog living in Austria, just outside Vienna.
0:28:01 > 0:28:07She's conducted a series of experiments, and is amazed at the dog's intelligence.
0:28:07 > 0:28:11Known only the pseudonym Betsy, the true identity of this
0:28:11 > 0:28:14seven-year-old border collie is a closely guarded secret.
0:28:14 > 0:28:16She can distinguish objects by name,
0:28:16 > 0:28:20which is really amazing, and she has many, many words.
0:28:20 > 0:28:22Kase.
0:28:24 > 0:28:27Das Zebra.
0:28:27 > 0:28:34With a vocabulary of over 340 words, Betsy is pushing the boundaries of what we think dogs are capable of.
0:28:37 > 0:28:39Karotte.
0:28:39 > 0:28:42Sandwich.
0:28:48 > 0:28:53I think it was when she was four or five months old,
0:28:53 > 0:28:57when she spontaneously started to connect human words to items.
0:28:57 > 0:29:00When we were discussing shall we play with the rope,
0:29:00 > 0:29:05or with the ball, she immediately started to bring those items. So it was actually her idea.
0:29:05 > 0:29:10And from this time on we started to really train her on different words.
0:29:10 > 0:29:13It was maybe one toy per week, and it worked.
0:29:15 > 0:29:19I think on average a well-trained dog maybe knows like 15 commands or something.
0:29:19 > 0:29:23There are just very few individuals who can do what she does.
0:29:23 > 0:29:26I can tell that I tried it with my own dog and it didn't work at all.
0:29:26 > 0:29:31So he could maybe distinguish two objects after a while and after extensive training,
0:29:31 > 0:29:37but she is really able to learn this easily and more than 300 objects, that's pretty amazing.
0:29:37 > 0:29:42Betsy's understanding of vocabulary rivals that of a two year old,
0:29:42 > 0:29:47so Kaminski decided to test her on other key developmental milestones.
0:29:47 > 0:29:50Can you go find me one of them over there? Yeah?
0:29:50 > 0:29:53Two year olds are just beginning to understand
0:29:53 > 0:29:58the use of physical symbols, such as scale models in communication.
0:29:58 > 0:30:06Though it looks easy, it requires abstract thinking way beyond the capability of almost all animals.
0:30:06 > 0:30:09But would Betsy be able to do this too?
0:30:18 > 0:30:19SHE SPEAKS GERMAN
0:30:24 > 0:30:28This was something the owners have never tried before, so when I came and I said, "I want to do this,"
0:30:28 > 0:30:33they were like, "No way, that's not going to work", but I was the first one doing it with her.
0:30:33 > 0:30:36And she had no problem doing it right from the beginning.
0:30:36 > 0:30:40This is surprising because in its essence if I hold out an object,
0:30:40 > 0:30:42she turns it into something communicative,
0:30:42 > 0:30:45and that's so interesting.
0:30:49 > 0:30:56- What about this one?- Children also begin to grasp that a drawing or photograph can depict a real object.
0:30:56 > 0:31:00- Thank you very much, well done. - No other dog has ever achieved this under trial conditions.
0:31:02 > 0:31:06But once again, Betsy picked this up almost immediately.
0:31:11 > 0:31:19In its essence the picture is something very different as the object, so it's a piece of paper
0:31:19 > 0:31:24and it's two-dimensional, but it's representing something, so she obviously interprets
0:31:24 > 0:31:30that as representing an object, a three-dimensional object, and that's so interesting that she does this.
0:31:30 > 0:31:32I know exactly what you want.
0:31:32 > 0:31:36This is the one you want and I'm going to go and get it for you.
0:31:36 > 0:31:40SHE SPEAKS GERMAN
0:31:42 > 0:31:47Kaminski is unsure how many dogs might have similar abilities, but Betsy is proof
0:31:47 > 0:31:52that certain dogs may have the potential to be more intelligent than we ever thought possible.
0:32:00 > 0:32:03So how did the dog acquire these unique abilities?
0:32:03 > 0:32:06Did they evolve them over thousands of years,
0:32:06 > 0:32:10or is it the way dogs have been brought up in a human environment that counts?
0:32:15 > 0:32:18Dogs and wolves are still the same species today.
0:32:18 > 0:32:20They can easily interbreed.
0:32:20 > 0:32:25Overall, wolves and dogs are 99.8% genetically identical.
0:32:28 > 0:32:34Given they're biologically so similar, is it the way we raise them in our homes that makes a dog?
0:32:34 > 0:32:39Scientists in Hungary set out to answer this question.
0:32:39 > 0:32:45- We wanted to see whether the special relationships between humans
0:32:45 > 0:32:48and dogs are due to nature or nurture.
0:32:48 > 0:32:53So we wanted to see what happens if a wolf is raised
0:32:53 > 0:32:59in a human environment, in a home, whether it would act like a dog or not.
0:33:01 > 0:33:07A litter of five-day old wolf cubs was taken from a wolf sanctuary outside Budapest.
0:33:07 > 0:33:14A group of young researchers became their adoptive parents, caring for them 24 hours a day.
0:33:14 > 0:33:17As a control for the experiment, they'd already raised puppies.
0:33:17 > 0:33:22Now they aimed to raise the wolf cubs the same way.
0:33:22 > 0:33:29So we were especially nice with our cubs, because we wanted to maintain a very good relationship with them.
0:33:32 > 0:33:39They were really cute, so it was not very difficult to carry them everywhere we were going.
0:33:39 > 0:33:43And we also slept together with the cubs.
0:33:43 > 0:33:46So the bonding, it was good.
0:33:46 > 0:33:52I really liked my cubs and there was a really strong relationship between us.
0:33:52 > 0:33:56But then something began to change.
0:33:56 > 0:34:02Despite raising the cubs in the same way as the puppies, by eight weeks the differences had started to show.
0:34:05 > 0:34:10Dog puppies were always interested in what I was doing.
0:34:10 > 0:34:13There is a very strong co-operative
0:34:13 > 0:34:19tendency in dogs and this was missing in wolves.
0:34:19 > 0:34:25They had their own ideas, they were not much interested in my activities.
0:34:27 > 0:34:33The researchers wanted to find out what was going on, and decided to run a series of tests
0:34:33 > 0:34:37comparing the wolf cubs with puppies of the same age.
0:34:37 > 0:34:39TOY YAPS
0:34:55 > 0:34:59Unlike dogs, the wolf cubs didn't respond to pointing.
0:34:59 > 0:35:02In fact they hardly made eye contact with humans at all.
0:35:04 > 0:35:07The cubs were behaving as they would do in the wild.
0:35:10 > 0:35:12CUB GROWLS
0:35:15 > 0:35:17She was really possessive.
0:35:17 > 0:35:22If she wanted to grab an object, it was really difficult to get it back.
0:35:22 > 0:35:29And if we wanted to open the refrigerator and have breakfast,
0:35:29 > 0:35:33the pup was immediately in the middle of the refrigerator and grabbed something.
0:35:33 > 0:35:39It is not like with a dog that you say, "No, you shouldn't."
0:35:39 > 0:35:40It just didn't care.
0:35:45 > 0:35:47The battles continued to get worse.
0:35:47 > 0:35:53After the second month, we started to have more and more conflicts
0:35:53 > 0:35:56and the wolves wanted to destroy everything.
0:35:57 > 0:36:00And of course when the cub is a small cub,
0:36:00 > 0:36:06it's nothing, but when they reach 40 or 50 kg, you know,
0:36:06 > 0:36:08it starts to be really dangerous.
0:36:08 > 0:36:13We just could not keep them in the house any more.
0:36:13 > 0:36:16Hoo!
0:36:16 > 0:36:20After four months the cubs had to be returned to the reserve.
0:36:20 > 0:36:24The experiment had proved that upbringing has little impact.
0:36:24 > 0:36:29It's impossible to turn a wolf into a dog, no matter how much you nurture it.
0:36:31 > 0:36:37So according to our experiences, the dog is not a socialised wolf at all.
0:36:37 > 0:36:42These differences we experienced in the community viability
0:36:42 > 0:36:47and in the social behaviour of dogs, this is the effect of domestication.
0:36:47 > 0:36:53The difference must lie in the way dogs have been bred by humans over thousands of years.
0:36:53 > 0:36:58Their unique abilities are now part of their nature.
0:37:03 > 0:37:07But how did dogs evolve these innate attributes?
0:37:07 > 0:37:11What was the process that made them intrinsically tame?
0:37:14 > 0:37:22A remarkable experiment in Siberia may hold the key to understanding how wolves turned into dogs.
0:37:22 > 0:37:24CAR HORN TOOTS
0:37:26 > 0:37:3350 years ago, Soviet scientists set up a breeding programme to try and domesticate silver foxes.
0:37:37 > 0:37:42The scale of the project has opened a remarkable window on domestication.
0:37:42 > 0:37:45It's become a focal point for scientists across the world.
0:37:47 > 0:37:52Here on a farm outside the city of Novosibirsk,
0:37:52 > 0:37:57the experiment still continues today, overseen by Dr Lyudmila Trut.
0:37:59 > 0:38:06The breeding programme began in 1959 when the first foxes were selected from local fur farms.
0:38:11 > 0:38:15TRANSLATION: We approached the animals in the cages
0:38:15 > 0:38:17and recorded their reactions to us.
0:38:17 > 0:38:22We could see that some of the foxes showed aggressive behaviour.
0:38:22 > 0:38:24Others were frightened.
0:38:24 > 0:38:29But only 1% of them showed neither signs of fear nor aggression.
0:38:33 > 0:38:40This 1% was selected to become the founding generation of a new population of foxes.
0:38:41 > 0:38:48At every generation, the selection process was repeated with only the tamest foxes being allowed to breed.
0:38:48 > 0:38:54Within just three generations, the aggressive behaviour began to disappear.
0:38:55 > 0:39:01TRANSLATION: The radical changes came through in the eighth generation,
0:39:01 > 0:39:04when foxes started to seek contact with humans
0:39:04 > 0:39:06and show affection to them.
0:39:06 > 0:39:14The amazing thing was that cubs who had just started to crawl, opened their eyes
0:39:14 > 0:39:16and started showing affection to humans
0:39:16 > 0:39:21while breathing heavily, wagging their tales and howling.
0:39:21 > 0:39:26This kind of response was a big surprise to us.
0:39:30 > 0:39:35Half a century on, the 50th generation of foxes are tamer than ever.
0:39:38 > 0:39:43It's an accelerated model of how dogs might have been domesticated from wolves.
0:39:50 > 0:39:56But tame foxes alone cannot unravel the mystery of domestication.
0:39:56 > 0:40:01A parallel group of silver foxes have also been bred to retain their aggressive behaviour.
0:40:21 > 0:40:25TRANSLATION: It just bit my hand.
0:40:27 > 0:40:31TRANSLATION: I didn't even open the cage.
0:40:31 > 0:40:35I just put my hand up and it managed to bite me through the bars.
0:40:43 > 0:40:46This isn't a fox - it's a dragon.
0:40:48 > 0:40:54It's allowed researchers to make unique comparisons between tame and aggressive foxes.
0:40:58 > 0:41:02TRANSLATION: We did an experiment with cross-fostering
0:41:02 > 0:41:06where we gave tame cubs to aggressive mothers.
0:41:06 > 0:41:12and vice versa. We found out that the mother's behaviour does not influence that of the cub.
0:41:13 > 0:41:17This cub was brought up by a tame mother.
0:41:20 > 0:41:23It showed something remarkable, that the difference
0:41:23 > 0:41:27between tame and aggressive foxes is largely in their genes.
0:41:27 > 0:41:34TRANSLATION: We even took the experiment one stage further and transplanted embryos
0:41:34 > 0:41:38from aggressive mothers into tame mothers,
0:41:38 > 0:41:44but the results were the same. It proved that you can't change the gene of aggressiveness
0:41:44 > 0:41:47and it will be kept and preserved for the next generation.
0:41:48 > 0:41:54Geneticists have already located several genetic regions responsible for tameness.
0:41:54 > 0:41:58They're now taking blood samples from tame and aggressive foxes
0:41:58 > 0:42:00in an attempt to pinpoint the specific genes.
0:42:03 > 0:42:09Dr Anna Kukekova, a molecular geneticist based at Cornell University in the USA,
0:42:09 > 0:42:12has travelled over 5,000 miles to study the foxes.
0:42:13 > 0:42:15Behaviour is complex.
0:42:17 > 0:42:20We're pretty sure there will be not a single gene different
0:42:20 > 0:42:22with the orchestra of genes
0:42:22 > 0:42:25which is responsible for this behaviour.
0:42:27 > 0:42:31She's hoping that once the precise genes are identified, it will lead
0:42:31 > 0:42:34to a better understanding of the biology of tameness.
0:42:36 > 0:42:40He is like a doggy, you know, like the puppy
0:42:40 > 0:42:44who's very happy when somebody picks him up from the floor.
0:42:47 > 0:42:54It's unbelievable how they trust, how they trust people and I just really admire these animals.
0:43:08 > 0:43:12TRANSLATION: So within 50 years of our intensive selection process,
0:43:12 > 0:43:16this fire-breathing dragon has turned into a human friend.
0:43:18 > 0:43:23If foxes were brought up in a domestic environment,
0:43:23 > 0:43:28interacting with other animals and humans, they would make fantastic pets.
0:43:29 > 0:43:37They are as independent as cats, but, at the same time, as devoted as any dog could be.
0:43:51 > 0:43:56But it's not just the fox's behaviour that has changed.
0:43:56 > 0:44:02Just a few generations into the experiment, scientists began to notice a curious phenomenon.
0:44:04 > 0:44:10The normal pattern and silver colour of the coat changed dramatically in some of the tame foxes.
0:44:10 > 0:44:14Their tails often became curly instead of straight.
0:44:14 > 0:44:20Some young foxes kept their floppy ears for much longer than usual,
0:44:20 > 0:44:25and their limbs and tails generally became shorter than their wild counterparts.
0:44:25 > 0:44:31In effect, the tame silver foxes were beginning to look more like dogs.
0:44:38 > 0:44:41What this shows is that when you select against aggression,
0:44:41 > 0:44:47you get almost all the same suite of changes that you see when you compare dogs to wolves.
0:44:47 > 0:44:52American anthropologist, Professor Brian Hare has visited the breeding programme in Siberia.
0:44:52 > 0:44:59He believes it shows that if you select for tameness, changes in appearance will naturally follow.
0:45:02 > 0:45:05I think the surprise when thinking about dog origins is that
0:45:05 > 0:45:09there's so many ways that dogs are different from wolves.
0:45:09 > 0:45:12So is it that you had to select for each of these traits individually?
0:45:12 > 0:45:15Well, the answer from the fox work is no.
0:45:15 > 0:45:20If you just select for behaviour, a lot of the morphological and physiological changes
0:45:20 > 0:45:22between wolves and dogs, get dragged along.
0:45:22 > 0:45:25You end up with this crazy variance, you know
0:45:25 > 0:45:31floppy ears, curly tails, you know, all these other things that are really cute to talk about.
0:45:31 > 0:45:35So you get a lot of stuff for free when you select against aggression.
0:45:35 > 0:45:40It's enabled him to draw some surprising conclusions about the process of domestication.
0:45:42 > 0:45:48When you're selecting against aggression, what you're doing is you're favouring juvenile traits.
0:45:48 > 0:45:52Juveniles and infants show much less aggression than adults
0:45:52 > 0:45:55and so what the idea is, is that you know
0:45:55 > 0:46:01basically you've frozen development at a much earlier stage
0:46:01 > 0:46:06and so you have an animal as an adult that looks and behaves much more like a juvenile.
0:46:06 > 0:46:12The theory is that dogs are in many ways like juvenile wolves.
0:46:12 > 0:46:16It explains how dogs could have begun to look so different from the wolves they came from.
0:46:18 > 0:46:20It's amazing that you get this variance
0:46:20 > 0:46:23that's hidden under the surface that expresses itself.
0:46:23 > 0:46:27And then later people can directly decide, "I really like the one
0:46:27 > 0:46:30"with the curly tail and I'm going to put them together."
0:46:30 > 0:46:36And then you can end up having dogs that you know sort of shift in ways that people want them to go.
0:46:42 > 0:46:45In the past few hundred years, we've taken dogs' infantile features
0:46:45 > 0:46:51and emphasised them even further through selective breeding.
0:46:51 > 0:46:55We've created hundreds of breeds to fulfil different roles,
0:46:55 > 0:46:58but some of them have been bred purely for their looks.
0:46:58 > 0:47:01I think this kind of breeding really tells us a lot
0:47:01 > 0:47:06about what kind of people we are, what it is that we like about dogs.
0:47:06 > 0:47:10How would you to describe Laddy in one word.
0:47:10 > 0:47:12Uh...
0:47:12 > 0:47:13..cute.
0:47:13 > 0:47:15Cute, yeah.
0:47:15 > 0:47:19Cute, adorable and funny.
0:47:19 > 0:47:21I just look at her and I just smile.
0:47:21 > 0:47:24She's particularly cute when she's sleeping.
0:47:26 > 0:47:32We all know we find them cute, but what is it exactly that makes us respond to dogs so powerfully?
0:47:34 > 0:47:37Psychiatrist, Morton Kringlebach,
0:47:37 > 0:47:42has a theory as to why the way dogs look has such a profound impact on us.
0:47:42 > 0:47:45The need to nurture I think is something that is so deep in us
0:47:45 > 0:47:47that we find it very difficult to resist.
0:47:49 > 0:47:57Dogs, puppies have very infant-like features and maybe that's one of the reasons why we think
0:47:57 > 0:48:04they are so cute is that they remind us of the infants that we are - so to speak - programmed to like.
0:48:04 > 0:48:11There's something about the way that the facial features are organised that makes us want to care for them.
0:48:11 > 0:48:15It's about having a large forehead, it's about having large eyes, big ears...
0:48:15 > 0:48:21And there's something about that that almost unconsciously we cannot help ourselves but actually like.
0:48:25 > 0:48:28Are you feeding him now?
0:48:28 > 0:48:31We're just going to go one more scan.
0:48:31 > 0:48:38Dr Kringlebach is interested in exploring how strongly we respond to these infantile features.
0:48:40 > 0:48:44A state of the art MEG scanner was used to measure people's brain activity
0:48:44 > 0:48:48while they were looking at images of baby faces and adult faces.
0:48:54 > 0:48:59We found that within a seventh of a second there was activity in the frontal part of the brain,
0:48:59 > 0:49:06just over the eyebrows, in the orbitofrontal of cortex that was present when you were looking
0:49:06 > 0:49:11at the infant faces but not when you were looking at the adult faces.
0:49:11 > 0:49:17This part of the brain is very much involved in emotional responses, and so what we think we may
0:49:17 > 0:49:23have stumbled across here is really in many ways the brain equivalent of the parental instinct.
0:49:23 > 0:49:28There's almost like a wired-in automatic reaction.
0:49:30 > 0:49:36Kringlebach is now testing to see if we have a similar response to dogs' cute features.
0:49:36 > 0:49:39The data is still being analysed but he suspects
0:49:39 > 0:49:45there will be a comparable signature in regions of the brain associated with nurturing responses.
0:49:48 > 0:49:50Just as with the infant, when you're looking at dogs,
0:49:50 > 0:49:55you find it very hard to control your emotions, you find it very hard not to get that need to nurture.
0:50:01 > 0:50:03Wow, look at that! What a nice belly!
0:50:05 > 0:50:11Oh, you're so cute, yes you are. Oh, yeah!
0:50:11 > 0:50:16But responding to pets as though they were children can be seen in a very different light.
0:50:18 > 0:50:22I think we can think of little puppies brought home as parasites.
0:50:22 > 0:50:25They don't do anything useful, they're not perceived
0:50:25 > 0:50:27as a food source, they're not perceived as a guard dog.
0:50:27 > 0:50:29They are simply brought home for fun.
0:50:29 > 0:50:35They are essentially moving our focus away from having children on to having pets.
0:50:38 > 0:50:42I think it's safe to say that dogs have evolutionally been very successful.
0:50:42 > 0:50:46If you compare them to wolves, you'll see that wolves are now an endangered species
0:50:46 > 0:50:49while dogs, of course, are all around the world.
0:50:49 > 0:50:53The cuckoo is perhaps quite a good analogy, because the baby cuckoo, of course,
0:50:53 > 0:50:59being planted in somebody else's nest, prompts mother bird to look after baby cuckoo,
0:50:59 > 0:51:02even though there's nothing in it for the mother bird at all.
0:51:02 > 0:51:10They actually, through their behaviour, through their looks, get exactly what they want.
0:51:10 > 0:51:13They may be parasitic in that we cannot help ourselves, but what we get
0:51:13 > 0:51:17in return is probably sometimes much greater than what we put in.
0:51:33 > 0:51:37Experiments have proved what dog owners have always suspected.
0:51:37 > 0:51:42After thousands of years living together, dogs are attuned to us like no other animal.
0:51:45 > 0:51:48New research has taken our understanding of how dogs evolved
0:51:48 > 0:51:54to a whole new level and getting us closer to exactly what it means to be tame.
0:51:57 > 0:52:01Now dogs could be about to provide us with the greatest gift of all.
0:52:01 > 0:52:08When it comes to combating human disease, dogs could hold many of the answers.
0:52:08 > 0:52:13They're going to help us tackle some of the most dangerous diseases
0:52:13 > 0:52:15of our time that kill millions of people every year.
0:52:16 > 0:52:21Dr Elinor Karlsson, a geneticist at the Brode Institute, Harvard, is on the hunt
0:52:21 > 0:52:25for gene mutations that could throw light on human diseases.
0:52:27 > 0:52:32I think there's hundreds of diseases that are in common between dogs and humans.
0:52:32 > 0:52:36There's diabetes, there's various cardiac diseases, there's epilepsy,
0:52:36 > 0:52:43there's a lot of different cancers - bone cancers, breast cancers, brain tumours.
0:52:43 > 0:52:45The narrow gene pool within a dog breed
0:52:45 > 0:52:49makes it far easier to pinpoint genetic mutations than in humans.
0:52:49 > 0:52:54For more than 200 years, people have been making up all of these different breeds,
0:52:54 > 0:52:57and now we can just use them to study genetics.
0:52:57 > 0:53:01If you looked in a population of humans, all the people in a country like the UK,
0:53:01 > 0:53:06you'd have quite a lot of genetic variation across them. People would be quite different from one another.
0:53:06 > 0:53:09But within a breed, dogs are very similar to each other.
0:53:11 > 0:53:18Particular dog breeds are prone to certain diseases, and this makes them incredibly useful to study.
0:53:20 > 0:53:24Today, the team are taking blood samples from boxers,
0:53:24 > 0:53:27a breed that is susceptible to a fatal heart disease called cardiomyopathy.
0:53:29 > 0:53:32What happens is they have
0:53:32 > 0:53:34irregular heartbeat,
0:53:34 > 0:53:38and it compromises blood flow in their body,
0:53:38 > 0:53:44so it can cause collapse and also it can cause sudden cardiac death.
0:53:44 > 0:53:52It's an invisible disease that affects humans, too, causing sudden death in apparently healthy people.
0:53:52 > 0:53:59The DNA in boxers' blood could hold vital clues to the genetic causes of the disease.
0:54:07 > 0:54:13Dr Karlsson is part of the team that in 2005 mapped the dog genome,
0:54:13 > 0:54:17all 2.4 billion letters of the dog's DNA code.
0:54:17 > 0:54:22Once we had the dog genome sequence, we could design a gene chip, which would allow us to compare
0:54:22 > 0:54:26all of our sick dogs and our healthy dogs and find the genes that are causing diseases.
0:54:28 > 0:54:36Using a genotyping machine, Dr Karlsson is able to simultaneously analyse thousands of regions of DNA
0:54:36 > 0:54:41from boxers with and without cardiomyopathy.
0:54:41 > 0:54:46What you see when you compare sick dogs to healthy dogs and go across the genome from chromosome one
0:54:46 > 0:54:48to chromosome two and across is that most of the points
0:54:48 > 0:54:52are right near zero and there's not a lot of differences between the healthy dogs and the sick dogs,
0:54:52 > 0:54:57until you get to chromosome 17, and there all of a sudden you have a huge number of differences.
0:54:57 > 0:54:58This is exciting, because this means
0:54:58 > 0:55:02this is the region of the genome that holds the gene causing our disease.
0:55:03 > 0:55:09Karlsson's team have honed in on this region to pinpoint the exact gene.
0:55:09 > 0:55:12We've found a gene related to sudden cardiac death.
0:55:12 > 0:55:16We think there's another one because we haven't told the whole story yet.
0:55:16 > 0:55:20But we think we know what the mutation is in that gene causing the disease.
0:55:21 > 0:55:24Now the mutation has been identified,
0:55:24 > 0:55:28the team have been able to locate the corresponding gene in humans.
0:55:28 > 0:55:33It's accelerated a process that, without dogs, could have taken decades.
0:55:35 > 0:55:37By knowing what gene is causing it in dogs,
0:55:37 > 0:55:40we have an idea that this gene can cause this disease in humans.
0:55:42 > 0:55:47I think that there's probably a lot of diseases that are so complicated in humans
0:55:47 > 0:55:51that if we didn't have dogs it would take us a long time to start piecing it together.
0:55:51 > 0:55:54Dogs basically give us a huge head start on that.
0:55:54 > 0:56:01So I think this puts the benefits that dogs give us on a whole new level, and I think
0:56:01 > 0:56:08if they can help us cure those diseases, then we can really say that dogs are good for our health.
0:56:13 > 0:56:17It's a very important part of life to actually know a dog.
0:56:17 > 0:56:24And especially a dog that adores you like this has got to be good for yourself.
0:56:24 > 0:56:26It's kind of impossible to have a bad day
0:56:26 > 0:56:29when you're coming home to a wet nose and a waggy tail, I think.
0:56:29 > 0:56:33I can't imagine life without her.
0:56:33 > 0:56:36It's quite strange. We weren't lacking anything before we had him,
0:56:36 > 0:56:39and yet now we would feel that we were lacking if he wasn't here.
0:56:39 > 0:56:42They just enrich your life.
0:56:42 > 0:56:44They are the best thing ever.
0:56:44 > 0:56:45They keep you young.
0:56:47 > 0:56:49For a pet that's been around so long,
0:56:49 > 0:56:53dog research is an astonishingly new area of science.
0:56:53 > 0:56:58It's a very basic human need to have social relationships,
0:56:58 > 0:57:05and one of the wonderful things about dogs, of course, is they offer you a way of giving unconditional love
0:57:05 > 0:57:08and receiving unconditional love in the other end.
0:57:09 > 0:57:13Dogs are the ones that live with us in the same environment.
0:57:13 > 0:57:19They've been selected to live in this new environment, and they are specially tuned into humans,
0:57:19 > 0:57:22so humans are their natural social partner.
0:57:22 > 0:57:26But we're only just beginning to recognise their full potential.
0:57:26 > 0:57:31Understanding dogs has the capacity to give us insights into disease,
0:57:31 > 0:57:34the human mind and our very existence.
0:57:34 > 0:57:40I think one reason that there are almost seven billion people on earth is in large part
0:57:40 > 0:57:43due to the role that dogs have played in our evolutionary existence.
0:57:45 > 0:57:51While we can have good relationships with a wide variety of animals, historically, our relationship
0:57:51 > 0:57:54with dogs seems to have been the longest one with any domestic animal.
0:57:54 > 0:57:59Personally, I don't think it's any coincidence that the dog is referred to as man's best friend.
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