"Great apes are the closest living relatives of humans, yet they can be the most elusive of cousins." "With habitats often deep in rain forests or mountains, these are animals whose secret lives have only been documented in the last few decades." "But distant pockets of jungle like this contain the remnants of populations that share most of our genes, some of our appearance, and perhaps even a few of our thoughts." "Humans love to watch apes." "At zoos around the world, they always draw the biggest crowds." "From the acrobatic orangutan to the inventive chimpanzees and the majestic gorilla, these are the great apes." "We seem to respond to these animals because they are so much like us." "Apes instinctively nurse their infants to the left and nurture them through an extended childhood." "We may look different from apes because they appear to be much hairier." "The only real difference, however, is that our hairs are shorter and finer." "But surprisingly, they sprout almost as densely as those of the apes." "And apes may even dream like us." "During sleep, rapid eye movement occurs regularly." "It is one of the clearest outward signs of dreaming." "In the wild, the real lives of apes bear little resemblance to our perception of them." "Chimpanzees are not the cuddly clowns they so often seem." "They are rowdy, powerful, intelligent and live in complex communities." "Like us, they have lifelong friendships and rivalries." "Chimps live only in Africa, and only in areas where there are still forests," "characteristics they share with their larger cousins." "The first gorillas seen by outsiders were the lowland gorillas of West Africa." "With an especially lean and powerful physique that belies a gentle nature, they are by far the most numerous of several distinct gorilla races." "A thousand miles to the east, across an almost unbroken expanse of forest, the land rises steeply into a series of mountain chains." "This is the home of the much rarer mountain gorillas." "With a thick, darker coat and a stockier build, they are able to keep warm in the cold mountain climate." "At birth, a gorilla is only half the weight of a human baby, but it grows remarkably quickly to become the largest of all the apes." "A fully-grown male is nearly six feet tall and weighs in at around four hundred and fifty pounds." "Contrary to modern myth, male gorillas are rarely aggressive and will only charge humans as a last resort when their group is threatened." "Gorillas and chimpanzees are found only in patches of equatorial Africa." "But orangutans are an entire continent away from their cousins, suggesting that there may once have been great apes living in a broad swath from Africa to the Far East." "Today, orangutans live only on the islands of Sumatra and Borneo." "This is the ape that dared to be orange." "Yet far from being bold, orangutans are shy, solitary animals that rarely come in contact with one another." "They are the only truly tree-dwelling great apes and even sleep in nests high in the forest canopy." "Early naturalists believed that the male, with his massive cheek pads, must be a different species from the female, who is less than half his size." "All the great apes were identified only within the last few hundred years." "But their discovery was to transform the way we see ourselves." "In the 17th Century, tantalizing rumors emerged out of Africa." "They told of strange man-like creatures, one of them said to be a giant." "At first, they were dismissed as traveler's tales." "But then similar stories of a wild man began to filter back from the Far East." "By the end of the 18th Century, fiction had started to become fact." "Chimpanzees and orangutans were shown at zoos in Europe and their remarkable similarities to humans began to stimulate fierce scientific argument." "The mystery of Africa's giant ape remained, and it was not until the middle of the" "19th Century that a gorilla was finally cornered." "The discovery of the gorilla coincided with a scientific storm over Darwin's theory of evolution." "Could this apparently ferocious monster really be one of our distant cousins?" "But science soon lost out to profit, and zoo owners marauded through central Africa in search of specimens." "There we came into a clearing and found broken bamboo shoots, which we knew to be gorilla food." "They have been here all right." "Certainly have." "They cannot be that far away." "I told Osa to be careful, as this gorilla might bite her." "But she did not pay any attention to the warning." "From the first successful capture, gorillas were shipped around the world to feed a public appetite for a 20th Century monster." "But where do great apes come from?" "Apes are primates, an ancient and varied group of mammals." "Like this slender loris, the earliest primates were small and nocturnal, with hands and feet adapted for grasping and manipulation." "Early primates also developed binocular, or 3D vision." "Many mammals have eyes on the side of their heads that face outwards, ideal for keeping watch to the front and back" "But early in their evolution, primates gave up this defensive arrangement and the eye sockets rotated forward." "The two separate fields of vision were now merged." "The eyes were no longer early warning devices but effective range finders." "Judging distances and grabbing hold have continued to be critical skills for primates as they have adapted to new ways of life." "But to become great apes, primates needed to add another ingredient to their grasping limbs and binocular vision." "For most of the sixty-five million years of their evolution, most primates have been small and light." "Only a handful followed a different course." "The great apes gave up the advantages of being small to exploit the possibilities of being large and heavy." "Size dictates how an animal can move." "A monkey is light enough to leap and can use its long tail for steering and balance." "Strong, hinge-like joints and the arms and legs absorb the heavy shock of impact." "But apes are built differently." "To move safely in the trees, they must spread their greater weight." "The shoulderjoints spread apart, broadening the body." "The shoulders and hips become free-swiveling ball and socket connections, allowing the arms and legs to pivot in many directions." "Both longer arms and ultra-flexible wrists enable apes to reach, twist and grab from almost any angle." "The elbow joint opens flat, enabling apes to hang under branches." "Too heavy to leap, apes have no need for a tail, or such long legs." "Our own exceptionally flexible limb joints owe everything to these ape characteristics." "Twisting wrists, locking elbows and rotating shoulders are all physical signs of our shared evolution with gorillas, chimps and orangutans." "Size has its advantages." "It allows apes to muscle their way through life and to deter their predators." "Size can have its disadvantages, too." "Orangutans reduce the risk of mishaps with some calculated caution and a good, strong grip." "They usually maintain at least three firm points of contact at any one time." "This makes leaping literally impossible, a good thing, one hundred and fifty feet up in the forest canopy." "With a little careful calculation, the orangutan can also use its weight to good advantage." "Tarzan would be impressed." "But why are such big animals up in the trees at all?" "The answer is food." "Apes are mostly vegetarians, and the richest pickings are high up in the canopy." "Fruit provides apes with many of their energy needs." "Fruit also explains why apes need rain forests." "It is only in these warm and wet environments that plants are able to produce a continuous year-round crop of fruit, enough to satisfy the demands of these large and specialized feeders." "But this is no Garden of Eden." "The wonderful bunches of fruit on this fig tree behind me could easily give a misleading impression that it is simple to find food in the rain forest." "When the forest cannot supply their favorite diet, apes turn to whatever else is available, the so-called fallback foods." "Here we are with a selection of fallback foods." "And, one of the things that all the" "African apes eat a lot of is the pith from stems." "Now, if we can break it open, we can get a sense ofjust how strong they have to be and what a strange kind of food source this is that they are reduced to eating." "Slimy and not very pleasant." "Sometimes they eat young leaves off bushes and small trees." "Actually, this tastes a little bit better." "All the apes turn to bark, not the outside of the bark, but the inside part." "It is still very coarse." "Strip it off, and put that in their mouths and chew away." "Not very nice for us." "Now, I think that we are extremely lucky to be humans ourselves and have some much nicer alternatives." "Apes also face competition from other diners." "Productive trees are usually spread very thinly around the forest and, typically, their fruit ripens suddenly and with little warning." "But how does a slow-moving climber like the orangutan compete with a flyer like the hornbill?" "It uses a highly accurate mental map." "The orangutan probably knows which tree to aim for." "But to reach it quickly enough, it has to navigate accurately through a three-dimensional maze, taking into account unseen obstacles and gaps in the forest." "To select the best possible route, the orangutan must first recall and then compare different alternatives." "Having hit upon the quickest treetop pathway, it wastes no time in setting off." "Without this effiicient route finder, the orangutan would be in constant danger of expending too much energy searching for food." "That, eventually, would lead to starvation." "The way fruits ripen so haphazardly forces orangutans to lead solitary lives high in the canopy." "They also stay aloft to avoid the threat of tigers." "But in the African forests, chimpanzees face fewer dangers and can travel on the ground in search of food." "And here, the apes are more often predator than prey." "The chimps move swiftly into position." "Two large males driving some colobus monkeys into an ambush of waiting chimps." "A young colobus is targeted and surrounded as more chimps join the hunt." "The younger chimps approach for a share of the meat." "But they will not be rewarded until the more powerful individuals have had their share." "Some groups of chimpanzees achieve a fifty percent success rate in hunting, a performance well above the killing effiiciency of specialized predators like lions." "In the African highlands, life for the mountain gorillas appears generally relaxed." "Food is plentiful, and the group seems to be a close and amicable family." "A single, mature male known as the silverback, heads the group by virtue of his sheer size and fighting strength." "For male gorillas, success in adulthood will ultimately depend upon their fighting ability." "Roughhousing is the best way to train." "All of the nine youngsters in this group are probably the silverback's own offspring, so he seems content to put up with their high-spirited play." "Their father is, by definition, a successful role model and the youngsters follow him around with the devotion that looks something like hero worship." "But adolescent males prefer to steer clear of the silverback" "Sexually mature, yet forbidden to mate within the group, this younger so-called blackback finds himself on a collision course with the boss." "His sexual frustrations finally boil over and a young female is bullied into submission." "Out of view of the dozing silverback, the blackback mates with her." "But the blackback takes a serious risk" "Silverbacks do not share their females and are prepared to fight for them." "The result is a painful, but superficial, wound, a reminder of the silverback's power and dominance." "Within a year or two, the teenager will leave the group to search elsewhere for a mate." "Male aggression, especially toward females, is not limited to gorillas." "In the forests of Sumatra and Borneo, orangutans spend most of their time apart, and lead lives that are generally quieter than their African cousins." "But orangutans are brought together by the need for sex, and into conflict by the rules of mating." "A female orangutan takes nearly a decade to raise a child, and during that time she will not have mated." "But when at last she becomes fertile again, it is an event that pulls in the local males from miles around." "But ahead of the dominant males is a young, frustrated teenager." "Too small to compete against his elders, but small enough to outmaneuver them, he forces himself on a female." "Her child tries desperately to disrupt the attacker." "But when a big male appears, the stakes will be raised." "The angry dominant male smashes trees to signal his displeasure." "The only course for the weaker male is to retreat." "Male chimpanzees compete, too, but they can also cooperate." "Tightly-knit groups of related males work closely to defend their territory from rival gangs." "Individual rivalries are put aside and nowhere is discipline tighter than on border patrol." "If they can catch an outsider male alone, then there will be the chance of a kill." "By some estimates, about a third of adult males die in attacks like this, a staggeringly high murder rate." "A few million years ago, the humid jungles of Africa housed just one chimp-like creature." "The Congo Basin was then a huge land-locked lake." "Over time, a small river drained the lake, becoming the mighty Zaire River." "The river cut the forest in two, isolating populations of apes on opposite banks." "Those to the north became today chimpanzees and those to the south evolved into bonobos." "Naturalists did not distinguish bonobos from chimps until 1929." "But some of the clearest differences can be found in the status of females." "A female chimpanzee's life is rugged." "Ah, they have hardships, just in daily activities." "They are probably lower on the hierarchy, the social status, than males throughout the society and, for instance, males, beat them up, chase them, bully them around, and that does not happen in bonobo society." "The female bonobos are not bullied and chased." "Although there can be some aggression, it is very minor." "Female bonobos are never raped, ah, as far as we know." "They, ah, have first choice at feeding sites." "Their life is much more peaceful." "The physical differences between chimps and bonobos are quite telling." "Bonobos have shorter, smaller faces and a more slender physique, retaining many of the features seen in juvenile chimps." "They are rather like chimps frozen inside adolescent bodies." "Even their voices are high-pitched and childlike." "Like chimps, bonobos live in large, boisterous social groups." "But it is the lack of violence and the role of sex that is unusual." "Sex is clearly not all for reproduction." "Through orgies of touching and genital stimulation known as GG rubbing, females heal minor tensions and make peace." "What is happening is just another example of how the females are the stability in the community, is that the males hold back" "They are wimps, basically." "And the females will cross over and they will GG rub and they will interact with neighboring females." "Even though the communities maintain their stability, when they do have a chance to come together, there is non-aggressive interaction." "Bonobo life seems more gentle and caring in other ways, too." "When bonobos copulate, when they interact, they look into each other's eyes." "They gaze into each other's eyes and they communicate in those ways that chimps do not do." "And I think they miss a lot, the chimps miss a lot." "The male aggression that is so common in chimps is much reduced in bonobos." "And even relations between neighboring groups are often peaceful." "Why do they need to be aggressive?" "They do not have to fight for food." "They do not have to fight for sex." "They do not have to fight for inter-relationships." "They do not have to fight for space." "Why would they be aggressive?" "All ape societies have complex rules that the young need to learn." "The way they do this mirrors the development of a human child." "Want to play hide and seek with me?" "Are you hiding?" "Yeah." "At the age of two, humans are unable to picture and understand the world from someone else's perspective." "Where did Maggie go?" "Oh!" "There you are!" "I see you." "Oh!" "If she cannot see you, then you cannot see her either." "When she opens her eyes, she becomes visible." "Oh!" "There we are." "As they develop, human children acquire the missing mental trick" "A seven year-old is able to bridge the gap to another person's mind, to picture someone else's viewpoint and to imagine how his knowledge and intentions could be different from her own." "Great apes do not play chess." "But perhaps they, too, can think themselves into the minds of others." "The problem is, how do we find out if apes have this ability if they do not have language to tell us?" "Experiments at Washington Zoo may provide the answer to whether apes can perform this mental feat as well as we can." "This here?" "It is very easy for humans." "We do this all the time." "Ah, and what we are testing is how capable are apes of doing this, in this case an orangutan, when she is interacting with a human." "So the idea is, when I walk up to this situation, I am totally naive." "I do not know where the hidden food is." "I do not know which location it is in and I do not do anything unless she tells me to do it." "So what she will do is move me into the correct position, turn me around and push me towards where the food is hidden." "Now, she understands that I will uncover the food and hand it to her once she directs me towards it." "What is important is that she has to understand that I have a lack of knowledge in my mind about this situation." "But what if knowledge is not the only thing lacking?" "Okay?" "Put it right here and get Rob." "Rob Shumaker is now led in with his eyes covered." "Stop about here." "If Inda is truly to see things from Rob's perspective, she has to realize that just like her, Rob needs eyes to find the food." "In here?" "Okay." "Let us see." "Good girl!" "You were a smart girl that time." "Good girl." "That was good." "Good for you." "Okay." "Very good." "Okay." "All done." "Now things are still more complicated for Inda." "She is confronted by Rob and a second person whose eyes are covered." "But Inda knows that all humans, and not just Rob, need to see." "She really has bridged the gap into other minds." "That was okay." "We can share." "We got enough to share." "What she did very well was not only model the fact that both of us had a deficit of information, she understood that we did not know something that she knew, and on top of that, she modeled the" "visual field of the person that she chose to assist her." "So, by removing the bucket off of his head, what that demonstrates is, she understands what he sees when he looks at a situation." "She has moved outside of her own experience and she is modeling someone else's experience in her own mind." "To reach into the minds of others requires a sense of who you are." "When this monkey is confronted by its own reflection, it reacts as if it were facing another monkey." "But great apes are different." "In a single moment of insight, puzzlement turns into self-recognition and Azee sees not another ape, but himself, in all his finery." "Great apes are talented inventors." "An ape can not only assess a problem, but use or even invent tools to solve it." "By breaking some twigs to fit through the gap, the orangutan can flick and roll food into its mouth." "And if peanut butter is available, it can be used as a glue to create another kind of tool." "Tools have been used by some of the great apes in the wild for cracking nuts or fishing for insects or honey." "Tribes in Indonesia used to say that orangutans pretended not to talk to avoid being put to work" "We now know that speech is physically impossible for great apes." "But this orangutan comes to work each morning to learn how to communicate with humans." "Scientists at Washington Zoo are studying the learning and communication skills of orangutans." "It is offiicially labeled a language study, but Rob Shumaker and his team are not teaching the animals to talk" "Instead, they are teaching the recognition and use of symbols, so that the orangutans can communicate their wants and needs." "Good." "Okay." "Good job." "Very good." "I think we know quite clearly from other projects that apes are very capable of using abstract symbols and syntax to communicate." "Well, these are the basics of every language." "And what I would like to do is use this language ability to explore questions about behavior, perceptions, natural history, ah, ah, of orangutans that you could not explore by, say, the usual means of observation or," "seeing how they react in certain situations." "Do another piece?" "Ready?" "Now, watch, watch carefully." "No." "Let us try it one more time." "Start over." "Okay." "Try again." "Now watch what you are doing." "The great apes are set apart from their fellow primates not just by their size." "Unlike monkeys, they are thoughtful tool users and promising linguists." "They also have a self-awareness and, like us, a special ability to see and think as if they were someone else." "This will be the last one." "Ready?" "That is right." "Good!" "Okay." "Good, good." "You are doing a good job." "That is a boy." "It is now common knowledge that apes are remarkably smart." "Still, if they are so clever and adaptable, why have they not explored more varied habitats?" "Monkeys, like these baboons, thrive on the African plains." "But where are the apes?" "Just because apes are not visible now in the savanna, does not mean they have never existed here." "The strange, fossilized remains of early great ape relatives show that some were, indeed, adapted to life outside the forests." "The fossil record shows that these ape ancestors spread throughout" "Africa and the warmer parts of Europe and Asia." "Some of these now-extinct species lived in dry, patchy woodlands." "They were powerfully built animals, with strong, thickly enameled teeth, allowing them a coarser and grittier diet." "In the foothills of the Himalayas, live the greatest of all great apes." "At an estimated seven hundred pounds," "Gigantopithecus would have dwarfed a silverback gorilla." "It was an awesome giant that could have been the source of the legend of the Yeti." "But for reasons unknown," "Gigantopithecus and the so-called wood apes vanished." "Then, around five million year ago, another wave of apes emerged from the forest communities." "These new savanna apes rapidly diversified into several two-legged species." "Of these, only one survives to this day, Homo sapiens, or humans." "Since Charles Darwin first suggested that African apes gave rise to the human race, scientists have established a basic, but definitive, timeline." "The great ape family tree has roots that date back fifteen million years, to when the ancestors of orangutans first emerged." "Later, the ancestors of gorillas split off from the remaining African apes." "Then, just five million years ago, there was a third split, with two branches." "One eventually gave rise to chimpanzees and bonobos and the other, the human animal, the ape that changed the world." "The human ape has been the most adaptable of all the apes." "With the ability to thrive in nearly all the world's environments and climates, the human population has exploded to nearly six billion." "It would take around a hundred and twenty thousand large stadiums to contain us all." "But the entire world population of the other great apes, the gorillas, chimps, bonobos and orangutans, could be squeezed into just one stadium." "And each year, the number of apes continues to fall." "We have gone to great lengths to try to understand the great apes, from the details of their everyday lives to the intricacies of their impressive brain power." "But it is only within the past few decades that studies have begun in earnest." "What we have learned in that short time is that the differences between us and our great ape cousins are mostly skin deep." "Our DNA differs from chimps, gorillas and orangutans by between just one point six and three point six percent." "With genetic makeups that are so similar, how different can we really be?" "I do not think that humans and apes have wildly different abilities or capacities." "I think that you just may see, ah, different levels in different capacities, depending on which species you are talking about." "It may be that we are more preoccupied with the past and the future than I think apes are." "I think that may be one thing that does distinguish humans from the apes." "The concentrated efforts of universities, laboratories and zoos around the world are revealing more and more about our cousins from the forests." "To learn about them, is to protect and understand our own past, and may yet secure their future."