Interesting Articles

The Human Family Tree, It Turns Out, Is Complicated

It’s all Stanley Kubrick’s fault. A famous scene in the director’s 2001: A Space Odyssey features apes on all fours being clubbed by upright apes, suggesting early humans were a violent species who evolved bipedalism to free their hands for weapons.

Those kinds of images, wrong as they are, take root in pop culture and never let go, explains paleoanthropologist Jeremy DeSilva this week in “What Made Early Humans Smart.” Which is a shame, because the truth about our human ancestors is far more multifaceted and fascinating.

And the story gets more compelling every year, writes population geneticist Razib Kahn in “The Human Family Tree, It Turns Out, Is Complicated.”

Do you picture our hominin ancestors as hunters? Not so much. “They were the hunted,” DeSilva, a paleoanthropologist at Dartmouth College, writes. Let’s take another look, as modern paleoanthropologists have, at the Taung child’s skull, one of paleontology’s most famous fossils, the remains of a child from the species, Australopithecus africanus, discovered in 1924. A reanalysis of the Taung child, DeSilva tells us, showed talon marks in its eye sockets. “A bird of prey, probably a crowned eagle, must have plucked the Taung child from the ground and carried it off to be eaten.” See, I told you. Fun!

“Everything I thought I knew about why humans walk upright is wrong.” 

This is an interview with Jeremy DeSilva and his thoughts taken from Nautilus:
 

What are the most popular wrong scientific explanations for why humans walk upright?

As new evidence is discovered, we always can change our minds, right? But one wrong idea that’s still with us—the basis of 2001: A Space Odyssey—is we were a violent species from the get-go and evolved bipedalism to free our hands for weaponry. It was based on a misinterpretation of fossils discovered at a site called Makapansgat in South Africa. The bones were supposedly butchered at the hands of Australopithecus. But it turns out they were remains that had been consumed by hyenas. There’s another popular idea that we evolved bipedalism to see over tall grass. But honestly, if you’re looking over tall grass and see a predator, the worst thing you could do is run away on two legs. We’re too slow. It would make sense that you run away on all fours, when you could gallop at twice the speed of a typical human, or not even a typical human, an exceptional human.

So even Usain Bolt would be toast?

Yes, he would. Even the fastest human being that we can possibly imagine, probably the fastest human who’s ever lived, is pathetically slow compared to your typical quadrupedal animal on an African savanna. Usain Bolt tops out at about 28 miles an hour. That’s half the speed of a galloping zebra or antelope or leopard or lion.

The image of a chimpanzee turning into a human that we see on T-shirts may not be how this all unfolded.

“To me, the greatest revelation of your research is we didn’t evolve from hominins that walked on all fours.
We evolved from ones who already walked upright.“

This is a really hot topic in our field right now, and the field is divided on this, and I might be completely wrong; we’ll see as we find more fossils. But my interpretation from the key time periods when bipedalism was emerging, is that apes are not moving on their knuckles. They’re not adapted for life on the ground. Instead, they’re up in the trees, moving with hand-assisted bipedalism, much like an orangutan, gibbon, and siamang do now. We call them “lesser apes,” and they moved bipedally a lot. What’s interesting is the knuckle-walkers, gorillas and chimpanzees, don’t move bipedally very frequently.

We have fossils, mostly from Southern Europe, where apes appear to have a body posture that’s a little more upright. What’s fun is the possibility that knuckle-walking might actually be the more recently evolved locomotion. The image of a chimpanzee slowly turning into a human that we see on T-shirts and coffee cups and bumper stickers may not be how this all unfolded. It could very well be that the common ancestor was more upright, and that chimpanzees and gorillas evolved knuckle-walking independently.

That famous image is called “March of Progress.” Tell us about it.

“March of Progress” was an illustration done by a Russian artist, Rudolph Zallinger, in a 1965 Time-Life book called Early Man. It’s this beautiful foldout that shows ancient apes down on all fours, and it has them slowly rising up to modern humans. At the time, with the fossils we had, you could create a narrative like that. But in the last half century we’ve made so many amazing discoveries that show the human family tree is much more diverse. The pace of evolutionary change is quite different and it turns out that upright walking is the earliest of these evolutionary changes. The earliest bipeds on the ground were evolving from things that were upright to begin with in trees. Really all that happened was an ecological change. These hominins were living in environments that had fewer and fewer trees. To continue to get from point A to point B to get your fruit and other food resources, you already are pre-adapted for an upright posture and moving on two legs. In that case, bipedalism wouldn’t be a new locomotion, it’d be an old locomotion. It was just in a new setting on the ground, rather than in trees.

If bipedalism makes us slow, easy prey, why didn’t our ancestors go extinct? Why are we here?

It’s a great question. What are the advantages in freeing the hands? We could carry objects—food and babies. There are also thermo-regulatory adaptations. By being on two legs rather than four, you can disperse heat better. Maybe those things became factors that allowed us to survive.

What’s the most beneficially adaptive trait for early hominins to walk upright?

I don’t know. I would disagree with any characterization that said there was one reason. If there was one reason, we’d know it. It’d be obvious. In fact, bipedalism could have evolved independently in different hominins in Africa. With the fossils we have, there’s the tantalizing possibility that it didn’t just happen once. If we’ve learned anything about evolutionary trends, it’s that good ideas evolve over and over again. For instance, the evolution of feathers and dinosaurs independently evolved three times. You could get the independent evolution of bipedalism multiple times.

It’s a misnomer, isn’t it, to think only one hominin existed at a time?

It is. One of the things we’re learning from new fossil discoveries is there appears to be these different species of early human, or hominin, coexisting on the landscape with different anatomies or adaptations in their feet and legs. They would’ve walked very differently. A classic example is Lucy’s species, Australopithecus afarensis, who lived about 3.5 million years ago, spanning from Ethiopia to Tanzania.

A few years ago, a colleague of mine, Yohannes Haile-Selassie, discovered a partial foot skeleton in Ethiopia, in sediments dated to the same age as Lucy. The expectation was it’s a foot from Lucy’s species. But Lucy’s species didn’t have a grasping big toe, and this one does. It has other parts of the bony anatomy that are consistent with pushing off the ground on two legs. So here we have something walking on two legs, but walking on two legs very differently from the way Lucy and her kind did.

I tell my students all the time about how much fun it would be to jump in a time machine and go back to Africa 3 or 4 million years ago. You’d see all these different kinds of hominins coexisting on a landscape, eating slightly different things, moving in slightly different ways.

Usain Bolt tops out at about 28 miles an hour. That’s half the speed of a leopard or lion.

You write that Lucy’s life would have been hard. How so?

Imagine you’re just about the slowest animal in your environment. You’re small. Lucy was about three and a half feet tall, a full grown adult Australopithecus. She wouldn’t have gotten any bigger. Her growth plates are fused, her wisdom teeth had erupted. And she’s sharing the landscape with a Homotherium, a large saber tooth cat. They were ancestors of hyenas and were enormous. Some were ancestors of leopards and lions. All of these things would have gladly eaten an Australopithecus. In fact, we have some fossils with puncture marks in the back of the head. We know they got eaten.

Lucy would have woken up in a tree. That’s how you stay away from getting eaten at night. She would have had to have hang tight as large cats were finishing up their meals from that night. And she would have been hungry. To eat, her group would have to come down out of the trees. But if you’re a biped, you can’t just put a baby on your back. The baby’s going to slide right off.

Baby chimpanzees and baboons cling to the fronts or wide backs of their mothers. Being upright means we have to physically carry our kids. So now Lucy is physically carrying her kid. Now, in her arms, she’s got this little fleshy meal for any carnivore, and she needs to go find food for herself in an environment littered with predators. And yet she survived! What an amazing testament to the resilience of our ancestors. Their survival is why we’re here.

What were key traits of Lucy’s survival?

If you’re living in a cooperative group, as I think early hominins were, you’re sharing food. You give it to relatives, your own children, and to others in the group, who then reciprocate. That builds trust and a cooperative culture that is essential for survival. To me, the only way that hominins could’ve survived through these millions of years of living in an environment that is full of predators is if they looked after each other and were hyper cooperative with one another.

I LOVE LUCY: “I love fossils,” says Jeremy DeSilva. The paleoanthropologist loves the stories they tell, particularly the story of Lucy (a museum replica above), an Australopithecus afarensis, whose life would have been incredibly hard. “And yet she survived!”GregGrabowski / Shutterstock

How do paleoanthropologists know early hominins were cooperative?

One of the best pieces of evidence we have is a fossil of an individual who’s broken a leg bone, a femur. This is long before hospitals, doctors, casts, anything like that. The beauty of the fossil is you can see a healed fracture. Imagine 2 million years ago, you break your leg. There’s no way you should survive. But a hominin did. The key word is healed. He survived that trauma. I don’t think he could have done that alone.

Did bipedalism lead to cooperation?

I think so. We think about humans having evolved from something very chimpanzee-like, and chimpanzees can be incredibly aggressive and violent. But we are equally related to bonobos, who are not aggressive or violent. They’re female-dominated and don’t exhibit the same territorial behaviors that chimpanzees do. Now, we didn’t evolve from either of those. They’re our cousins. We share a common ancestor with them. But they provide an interesting mirror through which we think about ourselves and what that common ancestor was like.

We all know how awful humans can be to each other. That’s well-established. But we overlook the fact that humans are extraordinarily cooperative with one another, tolerant of each other, kind, helpful, and empathetic. To me, what allowed an ape to survive for millions of years on a difficult landscape without weaponry, was that we looked after each other, we took care of each other. We had each other’s backs. If someone was injured, we helped them to a tree.

Maybe it’s better to say cooperation is a byproduct of being a vulnerable biped.

That’s exactly right. An ape that’s bipedal and isn’t nimble in trees is a recipe for extinction. But here we are. Something allowed us to pass through those rigors of natural selection. And it’s cooperation. One of the prime examples is childbirth. In non-human apes, childbirth is relatively easy. The baby is usually facing forward, toward the mother’s belly, when it’s born. But in humans, because of the changes to the pelvis associated with walking on two legs, a baby has to corkscrew through the birth canal and it ends up being born facing backward most of the time, and that requires assistance. One of the cultural universals in humans is to have assistance during birth, usually in the form of an experienced midwife. If you’re trusting someone, another member of your group, during childbirth, then you’re going to trust them at other times.

How did bipedalism lead to brain development?

This one’s more speculative. We’re not entirely sure. Darwin hypothesized that bipedalism and tool use and canine reduction and brain size evolve in concert. You can see Darwin’s ideas in the “March of Progress” illustration. As bipedalism is getting more refined, brains are getting bigger. But that’s not consistent with the evidence. Instead, we find bipedalism goes back to the origins of the lineage. Brain size doesn’t inflate until much later. About 2 million years ago, we start seeing a real increase in brain size. The brains of Australopithecus get a little bit bigger than their predecessors, but nothing like what we see in genus homo. That leap in growth is about getting enough energy to sustain this energetically costly organ, the brain.

Energy is a zero-sum game, right? There’s only so much energy available and the body allocates it to the most demanding organs?

That’s right. One of the hypotheses about brain growth is derived from what’s called the “expensive tissue hypothesis.” Energy is allocated to the brain, but where are you getting that energy from? The argument is the digestive system. Essentially the intestines reduce in volume, and by reducing that expensive tissue, you’re able to allocate more energy to a larger brain. But if you do that, you’re not able to digest plants as well anymore, unless you cook them. So there seems to be this relationship between the diversification of our diet, eating more meat and marrow, scavenging, and hunting. And fire plays a role too, because now you can cook. All those things are fueling brain growth.

Where does bipedalism enter the picture?

Coinciding with this, we see an increase in leg length. We start to see a more human-like arch to the foot. It’s almost as if these final tweaks made bipedalism even more efficient, and allowed us to travel greater distances, expand our home range. By expanding our home range, we’re now able to extract more resources from our environment. We can eat animals and the plants from a larger radius.

Did bipedalism contribute to humans being omnivores?

I think it did. We can tell from isotope signatures in the teeth of our earliest ancestors that they were eating stuff in a forested environment. They were eating fruits and leaves, typically what an ape would eat. But when you get to Australopithecus, Lucy’s time, you get a huge shift in the profile of the isotopes. They show that Lucy started eating lots of different things in different environments. That’s consistent with a biped spending more time on the ground than in trees to get their food.

Remember, Lucy’s life was hard. She can’t afford to be a picky eater. She’s not going to search and search for that one thing she’s craving. There are predators all over the place. She’ll get eaten and her kid will get eaten. She needed to eat anything. She needed to eat grasses and leaves and fruit. Maybe there’s a carcass with a little bit of meat left on it, and she could munch on that. She could dig for underground tubers and munch on those. Insects, termites, birds, eggs, lizards, snails—you name it, she was eating it. And humans do that today.

I guess that shoots down the trendy diets that say we should eat one particular type of food because our early ancestors did.

[Laughs]. Whenever someone asks me about the Paleo diet, I’ll say, “Which population are you talking about? Are you talking about the humans who were living in Northern Asia, the humans who were living in Europe, the humans who were living in Africa on a grassland environment, the humans who were living in a forested region, the humans who were living on coasts?” During the Paleolithic, you’re going to have very different diets depending on the human population we’re talking about. It’s because humans are unbelievably, dietarily flexible. We can eat anything. In those varied habitats, we did eat everything. There’s no one-size-fits-all diet for humans.

Here we are in 2021, living in an entirely different world, of course, than our hominin ancestors did. How is bipedalism not adapted to contemporary life?

I threw out my back a couple of weeks ago and couldn’t walk. Our lower back is a mess. Most mammals move on all fours and their spine is horizontal, it operates like a suspension bridge. By being bipedal, we’ve turned that spine vertical, a bad idea. And to make sure that the torso is oriented over the hips, and that all of our joints are aligned and balanced, there’s a curve that’s introduced into the spine. A colleague of mine, Bruce Latimer at Case Western Reserve University, refers to this as a series of cups and saucers. That’s how unstable the spine is. Slip discs are very common. We’re one of the few mammals that develop scoliosis.

Then there’s the real nightmare: the foot. If you were going to challenge an engineer to design a structure that has to be compliant enough to absorb forces from the ground, but then rigid enough to push off the ground, and maybe even elastic enough that it can absorb some energy to push off the ground, the last thing they would do is make it out of 26 parts. And your foot has 26 individual bones. Between your two feet, you’ve got 52 bones, which is a quarter of your skeleton. A quarter of the human skeleton is made up of foot bones. Why? It’s because we’re modified apes, and apes need all those foot bones to grab onto trees; they use their feet in much the same way we use our hands. By evolving bipedalism, natural selection can only work with pre-existing forms. It tinkered with this ape foot. I think of it as using duct tape and paper clips to patch together and stiffen up this foot. And it’s good enough, right? We’re here and we can move from point A to point B. But evolution doesn’t care about comfort, and so we’ve got a lot of problems.

Is there a larger message about evolutionary biology in our anatomical problems?

Yes, and it comes back to what we were talking about before. Humans buffer themselves with culture. Is natural selection still operating on humans? Absolutely. It has for the last 6 million years. Our foot anatomy may be suboptimal and lead to problems. But we solve our problems culturally and socially. Thankfully, we’re not twiddling our thumbs and waiting for natural selection to solve them for us.

What are your thoughts on this? Leave your comments below (:

Next time more on our human ancestry and it will completely blow your mind!

Read the original article here: https://nautil.us/issue/102/hidden-truths/what-made-early-humans-smart

Part2: Humans Are One Mixed-Up Ape

Recent fossilized bone discoveries in China and Israel support the exciting possibility of new, previously unknown species of archaic humans that wandered the planet alongside Homo sapiens. These discoveries pose new questions regarding the nature of our interaction with other archaic human species.

Todd Disotell, a biological anthropologist and molecular primatologist at the University of Massachusetts Amherst, has headed research on primate genome sequencing, which at first concluded Homo sapiens didn’t interbreed with other species of early humans. But his and other scientists’ subsequent research has now reversed this conclusion, revealing that in fact hominins, or early humans, such as Homo sapiens, Neanderthals, Denisovans (first identified in Siberia in 2010), did interbreed. The evolution of humans is now best pictured not as a simple tree with branches but, Disotell says, borrowing the priceless term from Monty Python and the Holy Grail, “shrubbery.

I like to joke that the Middle Pleistocene was a lot like Middle Earth where you had Dwarves and Elves and Orcs.

Disotell, a member of the Center for the Study of Human Origin group at New York University talks about the truths of human evolution hiding in our genome. He casually revealed five surprises regarding our evolutionary history. His insights include recurring facts about introgressions—the transfer of genetic material from one species to another—that have upended the simple family tree of our evolution. This interview is presented under six headings and entirely in Disotell’s words.

Our Viral Origin

About 10 percent of our genome has a viral origin. Some of these viruses are ancient. They go all the way back to vertebrates. Some are more recent. Most of them were originally retroviruses, which insert themselves into the genome, much like HIV. But, over time, mutations occur and now they’re just woven into our DNA. If mutations occur in key regions of the viral DNA, it can make the viral DNA inactive so it can’t re-infect. We call those endogenous retroviruses. Some of them have become reactivated in the sense that certain proteins can be produced, not as a viral particle but as a protein. Some of these are quite important. One is associated with placental development. It allows the placenta to basically invade the uterus. That goes all the way back to the origin of placental mammals. Now it’s basically universally used in mammals.

This viral DNA complicates the tree of life because some viruses can pick up strands of DNA from other organisms. Then, when they infect other organisms, their descendants will have snippets of DNA from another branch of the tree of life. That’s pretty cool. You’ve brought branches of the tree of life together in a single organism. If you look at the branches of life, it’s not one clean tree. Instead of a bifurcating tree, I refer to human evolution as being more like a bush. A short, chubby bush with many branches—a “shrubbery,” to get Pythonesque.

Our Interbreeding Ancestors

In the last few hundred thousand years, multiple species of hominins existed and interbred with each other. In fact, I use this as a teachable moment in my classes to show that scientists can be wrong. I was wrong! Right before we discovered this, I wrote a series of papers that indicated there was no interbreeding. That was the basis of the Out of Africa model, that Homo sapiens replaced earlier hominids. All that data was from mitochondrial DNA. We didn’t think we were ever going to get data from nuclear DNA. But with new technologies, we can sequence billions of bases; little tiny fragments of them 50 to 100 bases long. If you can do billions of them, you can piece together the genome. We managed to get it out of Neanderthals initially, and lo and behold, when we screened those genomes against modern humans, people of Eurasian ancestry—and that includes Native Americans who came from Eurasia—have 1.5 to 2 percent Neanderthal DNA in them. After the sequencing with Denisovans, we realized that some people in Asia and Oceania—Papua New Guinea, the peninsulas of Indonesia, and Australia—had Denisovan DNA. Some of the people from New Guinea had a surprisingly high percent—as much as 5 percent. In Africa, it looks like there were two or three archaic introgressions—basically hybridization between two populations or species—in the last 50,000 to 100,000 years, and it looks like it was the same in India. I think there are up to seven or eight archaic introgressions into the human genome in different populations. I like to joke that the Middle Pleistocene was a lot like Middle Earth where you had Dwarves and Elves and Orcs; all these different creatures cohabiting the planet. 

Our Messy Genome

There is about 1 percent difference between our genes and a chimpanzee’s. But even the big phenotypic differences we see between people are only skin deep. If you look at every ape protein, they have every bone we have, every muscle we have, the same type of hair, and on and on. They’re just better adapted to their tropical rainforest environment.

About 15 percent of a chimp’s genome is closely related to gorillas. That means if we go back 7 or 8 million years ago, before humans, chimps, and gorillas split, you would have had a huge and variable population of apes. When you look at what region of Africa they were from, who mated with whom, and who diverged from whom, you have what we call “incomplete lineage sorting.” If you have a variable, incestual population, not all the descendants have the same alleles, or versions of a gene. When apes begin to diverge, for whatever reason, they would have still been able to interbreed with each other because they wouldn’t have been a separate species yet. With an ancestrally variable population, and subpopulations diverging after that, they’re going to carry with them different proportions of a species into their descended species.

Everyone wants their fossil to be the “oldest human fossil.”

When you look at our genome, you see this messiness from the ancestral variation. This gets back to the evolutionary tree being neither a clean thing within modern humans nor within human origins. New fossils are being discovered all the time. But it seems for every 5- to 7-million-year-old fossil we find, somebody says, “It’s human!” It could be. It could be chimp. It could be gorilla. I think it’s just bias showing. Everyone wants their fossil to be the “oldest human fossil.” 

Our Brains Aren’t That Unique

Our brain is the most different thing from our relatives because it’s so enlarged. There are definitely a few unique genes but not really many. Humans have extra copies of some genes that aren’t found in other primates. Most genes related to our brain development are found in other primates, but we may have more copies of them, or the expression and regulation of them might be different. Chimps have also evolved in the last millions of years, and the main difference between them and other ancestors seems to be with mating-related genes involving testes and sperm competition. We seem to have more changes in our brain genes, but they seem to have the most change in genes related to mating. Chimps are extremely promiscuous, so if you want to be the father, you have to contend with the female having mated with multiple males. Thus, the more swimmers you produce, the more likely one of them is to win.

We also now know, with the discovery of several new African hominids like Homo naledi and Australopithecus sediba, that some other species of humans—and remember the bushiness of human evolution—developed smaller brains and smaller body size, and that makes sense because the brain is full of incredibly energy-expensive tissue. If you can survive in some area with a smaller brain it would be advantageous compared to these big present lugs who have to fill it full of calories!

Our Language Isn’t So Special

Living humans who have a mutation in the famous FOXP2 gene have some language deficits, but that doesn’t make it the “language gene.” It’s just one of probably hundreds of genes involved in the production of language. The Neanderthals and Denisovans have the same allele for that gene as we do. It’s a huge argument if the Neanderthals had language. We can only infer it through their cultural record and archeological record. As far as we can see, most of their genes are the same; their overall morphology is very similar to ours. Some people think they couldn’t produce the same phonemes—the same sounds—that we can produce, but they could still produce many sounds. Were they doing symbolic language like we do? I don’t think that question is answerable at present. 

Our DNA Is Filled with Typos

We have a protein-centric view of the world; you take your DNA, you transcribe it into RNA, and then you translate it into proteins. But in reality, only a tiny portion of our DNA is transcribed, and then only a tiny portion of that is translated into proteins. Most proteins are a few hundred to maybe a few thousand amino acids long, but we only have about 20,000 to 25,000 proteins. If you do the math on that, it’s a tiny portion of the genome.

Sometimes when a series of genes are working in concert with each other, where they are located is what matters. The spacing between those genes is important, even though it doesn’t appear to do anything important. But how far apart genes are from each other is crucial because it causes things to happen or not happen.

And then we have copies of certain types of DNA. My favorite one is called a SINE, a noncoding RNA called “short interspersed nuclear element.” An example of them is called an Alu. We have a million copies of this 300-base stretch of DNA, and they’re just randomly spewed throughout the genome. They can actually be copied and land in a different part of the genome. They amount to a couple percent of your genome! And then we have long ones that are a couple thousand bases long, of which we have thousands of copies, and they’re also a couple percent of our genome. 

So, a significant portion of our genome is great stretches of DNA that don’t necessarily do anything. But if they’re copied into a part of the genome where they cause a gene to be disrupted or to be spaced further apart, they might have different activity. While these stretches don’t directly do anything themselves, where they are, and how many of them there are, is important, and could offer an advantage.

It’s interesting. If you have a mutation in one of the Alu elements, one of the SINE elements, it’s not going to do anything. In fact, we use those mutations to trace evolutionary history. Because it’s not doing anything, selection isn’t acting on it, but it occurred. It’s like a typo in a book. And we follow the series of typos.

Original text taken from Nautilus: https://nautil.us/blog/humans-are-one-mixed_up-ape

Part 3: Humans are not that special

Humans have long believed that we are somehow special. But many traits once considered uniquely human are shared with animals

Tool use was once considered a uniquely human ability (Credit: Anup Shah/NPL)

We once viewed ourselves as the only creatures with emotions, morality, and culture

A species, by definition, is unique. In that trivial sense humans are unique, just as house mice are unique.

But when we say humans are unique, we mean something more than that. Throughout history humans have created a seemingly impenetrable barrier between us and other animals.

As the philosopher Rene Descartes wrote in the late 1600s: “animals are mere machines but man stands alone”.

Darwin’s books weren’t universally adored after they were published, as shown by this satirical 1871 cartoon depicting Charles Darwin as an ape (Credit: Wikimedia Commons)

Charles Darwin was one of the first to speak out against this idea. In The Descent of Man, he wrote: “There is no fundamental difference between man and the higher mammals in their mental faculties” and that all the differences are “of degree, not of kind”.

He later extensively documented the similarities between human facial expressions and those of animals.

“If a young chimpanzee be tickled,” he noted, “as is the case of our young children a more decided chuckling or laughing sound is uttered”. He also observed that chimpanzees’ eyes wrinkle, sparkle and grow brighter when they laugh.

His thoughts were later forgotten or ignored. By the 1950s animals had been reduced to unemotional machines with mere instincts.

There was a taboo against attributing emotions to animals

The behaviourist BF Skinner thought all animals were much the same. “Pigeon, rat monkey, which is which, it doesn’t matter.” He said that the same rules of learning would apply to them all.

At the time, there was a prevailing attitude that they lacked intelligence. There was a taboo against attributing emotions to animals, says Frans de Waal of Emory University in Atlanta, US.

It was only when the primatologist Jane Goodall began her studies on wild chimpanzees in the early 1960s that things started to change, albeit slowly. Her mission was to look at chimpanzees in order to understand more about our ancient human ancestors.

From the beginning of her time in Africa, she saw strikingly human-like behaviours. In her early research she referred to the chimpanzees as “he” and “she” rather than “it”. She also gave them names, something previously unheard of in academia, and began to describe their unique personalities.

She saw chimpanzees fishing for termites with twigs.

This in itself was a ground-breaking finding. Until then, tool-use had been considered a uniquely human ability.

Her project leader at the time, the paleoanthropologist Louis Leakey said: “Now we must redefine ‘tool’, redefine ‘man’, or accept chimpanzees as humans.”

At a similar time, de Waal had been observing chimpanzees in Arnhem Zoo in the Netherlands. He saw many intricate social behaviours, and was frustrated by the lack of studies describing them. “My biology books were useless,” he says.

Chimpanzees are extremely good at reading each other’s facial expressions

For one, as Darwin had written about over 100 years earlier, de Waal also noted that tickling a young chimpanzee elicits the same smiling response as children. A study published in May 2015 has since shown that the same muscles are involved when chimps and humans smile.

Our incredible range of facial expressions may be unique, but look at the face of a chimpanzee for long enough and you will begin to see a similar complex repertoire of smiling and laughter.

We also know that they are extremely good at reading each other’s facial expressions. So are monkeys.

Chimpanzees have a wide range of facial expressions (Credit: Anup Shah/NPL)

Chimps’ social skills are the basis for another behaviour once thought to be uniquely human: morality.

Morality can be said to encompass fairness, altruism and empathy. For centuries our moral codes have been crucial to our notion of humanity. We have long believed that our heightened moral reasoning and empathy sets us apart from the beasts.

We know that children have a strong sense of fairness from an early age. For instance, they will share with friends, even if there is an obvious cost to them. They also seem to be innately altruistic: they will help pick up dropped objects without any prompts from as young as 14 months.

But other animals have an innate sense of fairness, too.

Capuchin monkeys know what’s fair and what’s not (Credit: Roland Seitre/NPL)

In 2003 de Waal published research looking into how capuchin monkeys reacted to an unfair payment.

After two monkeys had completed the same task, both would happily accept a cucumber as a reward. But when one was randomly given a more delicious grape instead, the other was not happy and began to refuse the cucumber.

Chimpanzees behave in a similar way. But what if a chimpanzee controlled the reward instead of a human experimenter?

We know that for the most part, they act selfishly when it comes to food. They are known to steal or hide it from rivals.

However, a 2013 study found that they also know the value of cooperation. They will share food even if there is nothing obviously in it for them. The study found that they will split a reward equally, just as humans do. In one task chimpanzees shared bananas in the same way that humans share money.

Chimpanzees also seem to be instinctively helpful. Just like young infants, chimpanzees will help humans reach for out-of-reach objects.

They also help each other. Chimpanzees will unlock a door that leads to food for a mate, even if the one doing the unlocking would not get any. In the wild researchers have witnessed chimpanzees helping disabled group members, adopting unrelated orphans and helping friends escape from poachers’ snares.

This sense of altruism must run deep in the animal kingdom, because rats will also save a friend from being soaked with water, even if it means getting wet themselves.

These studies suggest that cooperation is a useful survival trait for many species. If humans, chimps and rats all cooperate, the common ancestor of all three may have done so too.

“Chimpanzees live in a rich social environment, they depend on each other,” says Felix Warneken of Harvard University in the US. “It does not require a big society with social norms to elicit a deep-rooted sense that we care about others.”

Chimpanzees work together in many ways, such as mutual grooming (Credit: Anup Shah/NPL)

The long-held view that chimps are selfish and mean is no longer acceptable, says de Waal. “People say that morality comes from God, from religion,” he says, but we can clearly see the roots of morality in many other species.

Of course, with the good comes the bad. It would be misleading to only consider chimpanzees as helpful, moral creatures. Just like us, they have a dark side. There are many instances of fighting, murder and even infanticide.

Their society is built upon a complex, hierarchical social world where it is important to keep friends close. That means chimps can get manipulative. They also often deceive others. 

De Waal has called them “Machiavellian”, in reference to the deceitful power-grabbing techniques described by historian and philosopher Niccolo Machiavelli.

He saw that a dominant male chimpanzee, who had become powerful with the help of friends, became jealous if these allies associated with his rivals. In response, the male would keep them apart. “As soon as his best buddy starts grooming his rival he gets very upset and breaks it up,” says de Waal. “That’s a ‘divide and rule’ strategy.”

These insights all suggest that chimpanzees are socially aware and understand each other’s behaviour. But how good are they?

Humans can recognise the mental states of others, an ability psychologists call “theory of mind”. We can figure out what others are thinking and what their intentions are, and infer what another person does or does not know.

Children learn to do this from a young age, and there is now a lot of evidence that great apes possess many of these mind-reading skills.

We are not the only ones who can think about others as individuals with goals

For example, a subordinate chimpanzee will only pick up a tasty banana if he can do so without being seen by a more dominant chimp. The subordinate knows that the dominant chimp would claim it.

Chimps also have some understanding of human minds. They can tell the difference between a person who is unwilling to give them food and a person who is unable to so.

The latest line of evidence in this field shows that, after food is taken away from them, chimps will steal it back from an opaque box which the experimenter cannot see into. They leave the food in the clear box alone.

Clearly, we are not the only ones who can think about others as individuals with goals, intentions and perceptions, says Katja Karg of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, the lead author of the study.

Baby bonobos (Pan paniscus) are a lot like human children (Credit: Anup Shah/NPL)

The next step is to look at whether orang-utans have the same ability, says Karg. We split from them about 14 million years ago, so if they do, it would suggest our mind-reading skills are ancient.

Knowing someone else’s mental state also requires a conscious awareness of your own. That suggests that chimpanzees also have a degree of conscious awareness.

They are not the only ones. So far the ability has been found in many other apes, dolphins, Asian elephants and the European magpie.

Chimpanzees even have culture. They aren’t composing symphonies but culture can be defined as passing on knowledge, habits and transmission from one generation to the next.

You won’t see a chimp cooking a gourmet meal for his best friends but that misses the point. De Waal argues that chimps completely depend on cultural and social learning.

There is now abundant evidence for this. Wild chimp societies have developed different tool use, courtship and grooming behaviours, which they pass onto their offspring.

In the lab, chimps will conform, using tools in the same way that others do. This conformity is “a hallmark of human culture”, according to the researchers. The chimps conformed to their group’s social norms, even though another technique could have been just as useful.

Most recently, it has emerged that chimpanzees can learn to cook food, although they do need to be prompted. They would probably quite like a drink to go with it: a 17-year-long study found that they were partial to alcohol from fermented palm sap, and drank enough to show signs of inebriation. Suddenly that gourmet meal idea doesn’t look so far off.

Morality, consciousness and culture were all once considered to be uniquely human, but chimps have them all. So what is left?

Language is more than spoken words

Language, clearly. We can write whole books on the topic, chimps do not. We cannot look into their eyes and ask them how they are and expect a verbal response.

Nevertheless, it’s clear that they have a complex system of communication.

Chimpanzees lack the vocal structures to make the sounds we do. But language is more than spoken words: gestures and facial expressions also play an important role. When you take that into account, chimps suddenly don’t look so bad at language.

Chimpanzees do not have our advanced skills but they have many of the components of language. Kanzi the bonobo, with his language skills, is an extreme case – and he was trained by humans. But there is plenty that chimps can do for themselves.

Chimps have intricate ways of communicating with each other

For instance, one study found that chimps beckon in the same way we do. Other work identified 66 distinct gestures, which all conveyed meaningful information.

They even have cultural variations for the world “apple”, which were discovered when a group of Dutch chimps was re-homed to a Scottish zoo.

It is clear that chimps, like many other species, have intricate ways of communicating with each other. The fault has been ours: we have been slow to understand what they are saying.

The more we look for similarities between humans and our relatives, the more we find. “For biologists we are one species out of many,” says de Waal.

The differences are not stark and absolute, but rather a matter of degree

He points to the way chimps kiss and embrace after a fight, in order to make up, just as humans do. “If you want to… say it’s a very different behaviour, then the burden falls on you to explain what’s so different about what the chimpanzees and humans are doing,” says de Waal.

There’s no doubt that human abilities are more developed than those of chimps, particularly when it comes to spoken language. The point is that the differences are not stark and absolute, but rather a matter of degree – and they get subtler the more we investigate them.

By that measure, humans are no more unique than any other animal.

Original post: http://www.bbc.com/earth/story/20150706-humans-are-not-unique-or-special

Part 4: What makes Humans different than other species?

No animal can get close to the devastation humans can cause (Credit: Thinkstock)

So, what exactly makes us special? The list might be smaller than it once was, but there are some traits of ours that no other creature on Earth can match.

Ever since we learned to write, we have documented how special we are. The philosopher Aristotle marked out our differences over 2,000 years ago. We are “rational animals” pursuing knowledge for its own sake. We live by art and reasoning, he wrote. 

Much of what he said stills stands. Yes, we see the roots of many behaviours once considered uniquely human in our closest relatives, chimpanzees and bonobos. But we are the only ones who peer into their world and write books about it.

We see the roots of many behaviours once considered uniquely human in our closest relatives

“Obviously we have similarities. We have similarities with everything else in nature; it would be astonishing if we didn’t. But we’ve got to look at the differences,” says Ian Tattersall, a paleoanthropologist at the American Museum of Natural History in New York, US.

To understand these differences, a good place to start is to look at how we got here. Why are we the only human species still alive today whereas many of our early-human ancestors went extinct?

Humans and chimpanzees diverged from our common ancestor more than six million years ago. Fossil evidence points to the ways which we have gradually changed. We left the trees, started walking and began to live in larger groups. And then our brains got bigger. Physically we are another primate, but our bigger brains are unusual.

Main stream scientists don’t know exactly what led to our brains becoming the size they are today (but I do, answer: extraterrestrials), but we seem to owe our complex reasoning abilities to it. 

It is likely that we have our big brain to thank that we exist at all. When we – Homo sapiens – first appeared about 200,000 years ago we weren’t alone. We shared the planet at least four other upright cousins; Neanderthals, Denisovans, the “hobbit” Homo floresiensis and a mysterious fourth group (we’ll get there in the next part, NH).

To understand these differences, a good place to start is to look at how we got here. Why are we the only human species still alive today whereas many of our early-human ancestors went extinct?

Neanderthals (left) didn’t fare as well as we did (Credit: SPL)

Evidence in the form of stone tools suggests that for about 100,000 years our technology was very similar to the Neanderthals. But 80,000 years ago something changed.

“The Neanderthals had an impressive but basically routine material record for a hominid. Once H. sapiens started behaving in a strange, [more sophisticated] way, all hell broke loose and change became the norm,” Tattersall says.

We started to produce superior cultural and technological artefacts. Our stone tools became more intricate. One study proposes that our technological innovation was key for our migration out of Africa. We started to assign symbolic values to objects such as geometrical designs on plaques and cave art.

There is little evidence that any other hominins made any kind of art

By contrast, there is little evidence that any other hominins made any kind of art. One example, which was possibly made by Neanderthals, was hailed as proof they had similar levels of abstract thought. However, it is a simple etching and some question whether Neanderthals made it at all. The symbols made by H. sapiens are clearly more advanced. We had also been around for 100,000 years before symbolic objects appeared so what happened?

We had the capacity for art early in our history (Credit: SPL)

Somehow, our language-learning abilities were gradually “switched on”, Tattersall argues. In the same way that early birds developed feathers before they could fly, we had the mental tools for complex language before we developed it.

We started with language-like symbols as a way to represent the world around us, he says. For example, before you say a word, your brain first has to have a symbolic representation of what it means. These mental symbols eventually led to language in all its complexity and the ability to process information is the main reason we are the only hominin still alive, Tattersall argues.

It’s not clear exactly when speech evolved, or how. But it seems likely that it was partly driven by another uniquely human trait: our superior social skills.

What happened in our evolution to make us reliant on each other?

Something must have happened in our evolution, Tomasello says, to make humans increasingly reliant on each other. (Read The 12th Planet by Sitchin to find out exactly what happened. NH). Our brains needed fuel to get bigger and so collaborative hunting may have played a key role in that. Our advanced teamwork may simply reflect our long history of working together to get food.

Mind readers

The fact that our nearest relatives share too simply shows that it is an ancient trait. It was already present in the messy branch of early humans that led to us, but none of these other species were as hyper cooperative as we are today.    

We connect up our brains, and it’s one of our defining traits, but it doesn’t make us unique. Dolphins, ants, bees, any many other species make use of the divine matrix much more efficiently and communicate with each other without using technology like humans tend to do. But we all have it in us to do so with intent. Watch Superhumans on Gaia Tv to find out more. NH

That our rapidly expanding technology has allowed us all to become instant publishers means we can share such information at the touch of a button. And this transmission of ideas and technology helps us in our quest to uncover even more about ourselves. That is, we use language to continue ideas that others put forward.

Of course, we pass on the good and the bad. The technology that defines us can also destroy worlds.

Take murder. Humans aren’t the only species that kill each other. We’re not even the only species that fight wars. But our intelligence and social prowess mean we can do so on an unprecedented scale.

We can fight and kill on an unparalleled scale (Credit: istock)

Charles Darwin, in his book The Descent of Man, wrote that humans and animals only differ in degree, not kind. This still stands true but Suddendorf says that it is precisely these gradual changes that make us extraordinary and has led to “radically different possibilities of thinking”.

And it is these thoughts that allow us to pinpoint to our differences with chimpanzees. That we do so is because they are the closest living relative we have. If any of the now extinct early humans were still alive, we would be comparing our behaviour to them instead.

Still, as far as we know, we are the only creatures trying to understand where we came from. We also peer further back in time, and further into the future, than any other animal. What other species would think to ponder the age of the universe, or how it will end?”

We have an immense capacity for good. At the same time we risk driving our closest relatives to extinction and destroying the only planet we have ever called home.

Original post: https://www.bbc.com/future/article/20150706-the-small-list-of-things-that-make-humans-unique

Part 5: Forbidden Archaeology

The history we were taught in school is a complete lie in order to coverup our true earth origins as a way to keep us in subservience, control and conformity.

Over the past two centuries, archaeologists have found bones, footprints, and artifacts showing that people like ourselves have existed on earth for vast periods of time, going back many millions of years. But many scientists have forgotten or ignored these remarkable discoveries. Primarily because they contradict the now dominant views about human origins and antiquity. According to these views, humans like ourselves have existed for less than 200,000 years, and before that there were only more primitive human ancestors. This evolutionary paradigm, to which influential groups of scientists are deeply committed, has acted as a “knowledge filter.” And the filtering, intentional or not, has left us with an incomplete set of facts for building our ideas about human origins.

Recovering the complete set of facts takes us on a fascinating expedition, across five continents to key archaeological sites, some long forgotten, some the center of ongoing controversy. These facts are consistent with the accounts of human origins and antiquity found in the Puranas, the historical writings of ancient India.

Speaker: Michael A. Cremo is researcher in the history of archeology. He is a member of the World Archaeological Congress and the European Association of Archaeologists. Cremo is the principal author of the book Forbidden Archaeology, a comprehensive historical survey of archaeological anomalies. In a review in British Journal for History of Science, archeologist Tim Murray said the book “provides the historian of archaeology with a useful compendium of case studies in the history and sociology of scientific knowledge, which can be used to foster debate within archaeology about how to describe the epistemology of one’s discipline. ” Cremo is particularly interested in examining the history of the archeology from the standpoint of alternative world views, particularly worldviews with foundations in ancient Indian thought. He has presented his findings at some of the leading scientific institutions in the world, such as the Royal Institution in London and various national academies of science, such as the Russian Academy of Sciences in Moscow. He regularly presents papers at major international scientific conferences on archeology and history of science. Several of these papers have been appeared in peer-reviewed publications. He has also lectured at hundreds of universities around the world. For more info visit http://www.mcremo.com.

Below: Michael Cremo is interviewed about his archeological discoveries and the cover up of the scientific community. Cremo gives several examples of archeological evidence that has been suppressed by the establishment in the name of “scientific conformity”. His books include ‘The Hidden History of the Human Race (The Condensed Edition of Forbidden Archeology)‘ and ‘Forbidden Archaeology‘. Richard Thompson is credited by Michael Cremo as a valuable partner in his research.