Posts Tagged ‘evolution’

by John H. Richardson

In an ordinary hospital room in Los Angeles, a young woman named Lauren Dickerson waits for her chance to make history.

She’s 25 years old, a teacher’s assistant in a middle school, with warm eyes and computer cables emerging like futuristic dreadlocks from the bandages wrapped around her head. Three days earlier, a neurosurgeon drilled 11 holes through her skull, slid 11 wires the size of spaghetti into her brain, and connected the wires to a bank of computers. Now she’s caged in by bed rails, with plastic tubes snaking up her arm and medical monitors tracking her vital signs. She tries not to move.

The room is packed. As a film crew prepares to document the day’s events, two separate teams of specialists get ready to work—medical experts from an elite neuroscience center at the University of Southern California and scientists from a technology company called Kernel. The medical team is looking for a way to treat Dickerson’s seizures, which an elaborate regimen of epilepsy drugs controlled well enough until last year, when their effects began to dull. They’re going to use the wires to search Dickerson’s brain for the source of her seizures. The scientists from Kernel are there for a different reason: They work for Bryan Johnson, a 40-year-old tech entrepreneur who sold his business for $800 million and decided to pursue an insanely ambitious dream—he wants to take control of evolution and create a better human. He intends to do this by building a “neuroprosthesis,” a device that will allow us to learn faster, remember more, “coevolve” with artificial intelligence, unlock the secrets of telepathy, and maybe even connect into group minds. He’d also like to find a way to download skills such as martial arts, Matrix-style. And he wants to sell this invention at mass-market prices so it’s not an elite product for the rich.

Right now all he has is an algorithm on a hard drive. When he describes the neuroprosthesis to reporters and conference audiences, he often uses the media-friendly expression “a chip in the brain,” but he knows he’ll never sell a mass-market product that depends on drilling holes in people’s skulls. Instead, the algorithm will eventually connect to the brain through some variation of noninvasive interfaces being developed by scientists around the world, from tiny sensors that could be injected into the brain to genetically engineered neurons that can exchange data wirelessly with a hatlike receiver. All of these proposed interfaces are either pipe dreams or years in the future, so in the meantime he’s using the wires attached to Dickerson’s hippo­campus to focus on an even bigger challenge: what you say to the brain once you’re connected to it.

That’s what the algorithm does. The wires embedded in Dickerson’s head will record the electrical signals that Dickerson’s neurons send to one another during a series of simple memory tests. The signals will then be uploaded onto a hard drive, where the algorithm will translate them into a digital code that can be analyzed and enhanced—or rewritten—with the goal of improving her memory. The algorithm will then translate the code back into electrical signals to be sent up into the brain. If it helps her spark a few images from the memories she was having when the data was gathered, the researchers will know the algorithm is working. Then they’ll try to do the same thing with memories that take place over a period of time, something nobody’s ever done before. If those two tests work, they’ll be on their way to deciphering the patterns and processes that create memories.

Although other scientists are using similar techniques on simpler problems, Johnson is the only person trying to make a commercial neurological product that would enhance memory. In a few minutes, he’s going to conduct his first human test. For a commercial memory prosthesis, it will be the first human test. “It’s a historic day,” Johnson says. “I’m insanely excited about it.”

For the record, just in case this improbable experiment actually works, the date is January 30, 2017.

At this point, you may be wondering if Johnson’s just another fool with too much money and an impossible dream. I wondered the same thing the first time I met him. He seemed like any other California dude, dressed in the usual jeans, sneakers, and T-shirt, full of the usual boyish enthusiasms. His wild pronouncements about “reprogramming the operating system of the world” seemed downright goofy.

But you soon realize this casual style is either camouflage or wishful thinking. Like many successful people, some brilliant and some barely in touch with reality, Johnson has endless energy and the distributed intelligence of an octopus—one tentacle reaches for the phone, another for his laptop, a third scouts for the best escape route. When he starts talking about his neuroprosthesis, they team up and squeeze till you turn blue.

And there is that $800 million that PayPal shelled out for Braintree, the online-­payment company Johnson started when he was 29 and sold when he was 36. And the $100 million he is investing into Kernel, the company he started to pursue this project. And the decades of animal tests to back up his sci-fi ambitions: Researchers have learned how to restore memories lost to brain damage, plant false memories, control the motions of animals through human thought, control appetite and aggression, induce sensations of pleasure and pain, even how to beam brain signals from one animal to another animal thousands of miles away.

And Johnson isn’t dreaming this dream alone—at this moment, Elon Musk and Mark Zuckerberg are weeks from announcing their own brain-hacking projects, the military research group known as Darpa already has 10 under way, and there’s no doubt that China and other countries are pursuing their own. But unlike Johnson, they’re not inviting reporters into any hospital rooms.

Here’s the gist of every public statement Musk has made about his project: (1) He wants to connect our brains to computers with a mysterious device called “neural lace.” (2) The name of the company he started to build it is Neuralink.

Thanks to a presentation at last spring’s F8 conference, we know a little more about what Zuckerberg is doing at Facebook: (1) The project was until recently overseen by Regina Dugan, a former director of Darpa and Google’s Advanced Technology group. (2) The team is working out of Building 8, Zuckerberg’s research lab for moon-shot projects. (3) They’re working on a noninvasive “brain–computer speech-to-text interface” that uses “optical imaging” to read the signals of neurons as they form words, find a way to translate those signals into code, and then send the code to a computer. (4) If it works, we’ll be able to “type” 100 words a minute just by thinking.

As for Darpa, we know that some of its projects are improvements on existing technology and some—such as an interface to make soldiers learn faster—sound just as futuristic as Johnson’s. But we don’t know much more than that. That leaves Johnson as our only guide, a job he says he’s taken on because he thinks the world needs to be prepared for what is coming.

All of these ambitious plans face the same obstacle, however: The brain has 86 billion neurons, and nobody understands how they all work. Scientists have made impressive progress uncovering, and even manipulating, the neural circuitry behind simple brain functions, but things such as imagination or creativity—and memory—are so complex that all the neuroscientists in the world may never solve them. That’s why a request for expert opinions on the viability of Johnson’s plans got this response from John Donoghue, the director of the Wyss Center for Bio and Neuroengineering in Geneva: “I’m cautious,” he said. “It’s as if I asked you to translate something from Swahili to Finnish. You’d be trying to go from one unknown language into another unknown language.” To make the challenge even more daunting, he added, all the tools used in brain research are as primitive as “a string between two paper cups.” So Johnson has no idea if 100 neurons or 100,000 or 10 billion control complex brain functions. On how most neurons work and what kind of codes they use to communicate, he’s closer to “Da-da” than “see Spot run.” And years or decades will pass before those mysteries are solved, if ever. To top it all off, he has no scientific background. Which puts his foot on the banana peel of a very old neuroscience joke: “If the brain was simple enough for us to understand, we’d be too stupid to understand it.”

I don’t need telepathy to know what you’re thinking now—there’s nothing more annoying than the big dreams of tech optimists. Their schemes for eternal life and floating libertarian nations are adolescent fantasies; their digital revolution seems to be destroying more jobs than it created, and the fruits of their scientific fathers aren’t exactly encouraging either. “Coming soon, from the people who brought you nuclear weapons!”

But Johnson’s motives go to a deep and surprisingly tender place. Born into a devout Mormon community in Utah, he learned an elaborate set of rules that are still so vivid in his mind that he brought them up in the first minutes of our first meeting: “If you get baptized at the age of 8, point. If you get into the priesthood at the age of 12, point. If you avoid pornography, point. Avoid masturbation? Point. Go to church every Sunday? Point.” The reward for a high point score was heaven, where a dutiful Mormon would be reunited with his loved ones and gifted with endless creativity.

When he was 4, Johnson’s father left the church and divorced his mother. Johnson skips over the painful details, but his father told me his loss of faith led to a long stretch of drug and alcohol abuse, and his mother said she was so broke that she had to send Johnson to school in handmade clothes. His father remembers the letters Johnson started sending him when he was 11, a new one every week: “Always saying 100 different ways, ‘I love you, I need you.’ How he knew as a kid the one thing you don’t do with an addict or an alcoholic is tell them what a dirtbag they are, I’ll never know.”

Johnson was still a dutiful believer when he graduated from high school and went to Ecuador on his mission, the traditional Mormon rite of passage. He prayed constantly and gave hundreds of speeches about Joseph Smith, but he became more and more ashamed about trying to convert sick and hungry children with promises of a better life in heaven. Wouldn’t it be better to ease their suffering here on earth?

“Bryan came back a changed boy,” his father says.

Soon he had a new mission, self-assigned. His sister remembers his exact words: “He said he wanted to be a millionaire by the time he was 30 so he could use those resources to change the world.”

His first move was picking up a degree at Brigham Young University, selling cell phones to help pay the tuition and inhaling every book that seemed to promise a way forward. One that left a lasting impression was Endurance, the story of Ernest Shackleton’s botched journey to the South Pole—if sheer grit could get a man past so many hardships, he would put his faith in sheer grit. He married “a nice Mormon girl,” fathered three Mormon children, and took a job as a door-to-door salesman to support them. He won a prize for Salesman of the Year and started a series of businesses that went broke—which convinced him to get a business degree at the University of Chicago.

When he graduated in 2008, he stayed in Chicago and started Braintree, perfecting his image as a world-beating Mormon entrepreneur. By that time, his father was sober and openly sharing his struggles, and Johnson was the one hiding his dying faith behind a very well-protected wall. He couldn’t sleep, ate like a wolf, and suffered intense headaches, fighting back with a long series of futile cures: antidepressants, biofeedback, an energy healer, even blind obedience to the rules of his church.

In 2012, at the age of 35, Johnson hit bottom. In his misery, he remembered Shackleton and seized a final hope—maybe he could find an answer by putting himself through a painful ordeal. He planned a trip to Mount Kilimanjaro, and on the second day of the climb he got a stomach virus. On the third day he got altitude sickness. When he finally made it to the peak, he collapsed in tears and then had to be carried down on a stretcher. It was time to reprogram his operating system.

The way Johnson tells it, he started by dropping the world-beater pose that hid his weakness and doubt. And although this may all sound a bit like a dramatic motivational talk at a TED conference, especially since Johnson still projects the image of a world-beating entrepreneur, this much is certain: During the following 18 months, he divorced his wife, sold Braintree, and severed his last ties to the church. To cushion the impact on his children, he bought a house nearby and visited them almost daily. He knew he was repeating his father’s mistakes but saw no other option—he was either going to die inside or start living the life he always wanted.

He started with the pledge he made when he came back from Ecuador, experimenting first with a good-government initiative in Washington and pivoting, after its inevitable doom, to a venture fund for “quantum leap” companies inventing futuristic products such as human-­organ-­mimicking silicon chips. But even if all his quantum leaps landed, they wouldn’t change the operating system of the world.

Finally, the Big Idea hit: If the root problems of humanity begin in the human mind, let’s change our minds.

Fantastic things were happening in neuroscience. Some of them sounded just like miracles from the Bible—with prosthetic legs controlled by thought and microchips connected to the visual cortex, scientists were learning to help the lame walk and the blind see. At the University of Toronto, a neurosurgeon named Andres Lozano slowed, and in some cases reversed, the cognitive declines of Alzheimer’s patients using deep brain stimulation. At a hospital in upstate New York, a neuro­technologist named Gerwin Schalk asked computer engineers to record the firing patterns of the auditory neurons of people listening to Pink Floyd. When the engineers turned those patterns back into sound waves, they produced a single that sounded almost exactly like “Another Brick in the Wall.” At the University of Washington, two professors in different buildings played a videogame together with the help of electroencephalography caps that fired off electrical pulses—when one professor thought about firing digital bullets, the other one felt an impulse to push the Fire button.

Johnson also heard about a biomedical engineer named Theodore Berger. During nearly 20 years of research, Berger and his collaborators at USC and Wake Forest University developed a neuroprosthesis to improve memory in rats. It didn’t look like much when he started testing it in 2002—just a slice of rat brain and a computer chip. But the chip held an algorithm that could translate the firing patterns of neurons into a kind of Morse code that corresponded with actual memories. Nobody had ever done that before, and some people found the very idea offensive—it’s so deflating to think of our most precious thoughts reduced to ones and zeros. Prominent medical ethicists accused Berger of tampering with the essence of identity. But the implications were huge: If Berger could turn the language of the brain into code, perhaps he could figure out how to fix the part of the code associated with neurological diseases.

In rats, as in humans, firing patterns in the hippocampus generate a signal or code that, somehow, the brain recognizes as a long-term memory. Berger trained a group of rats to perform a task and studied the codes that formed. He learned that rats remembered a task better when their neurons sent “strong code,” a term he explains by comparing it to a radio signal: At low volume you don’t hear all of the words, but at high volume everything comes through clear. He then studied the difference in the codes generated by the rats when they remembered to do something correctly and when they forgot. In 2011, through a breakthrough experiment conducted on rats trained to push a lever, he demonstrated he could record the initial memory codes, feed them into an algorithm, and then send stronger codes back into the rats’ brains. When he finished, the rats that had forgotten how to push the lever suddenly remembered.

Five years later, Berger was still looking for the support he needed for human trials. That’s when Johnson showed up. In August 2016, he announced he would pledge $100 million of his fortune to create Kernel and that Berger would join the company as chief science officer. After learning about USC’s plans to implant wires in Dickerson’s brain to battle her epilepsy, Johnson approached Charles Liu, the head of the prestigious neurorestoration division at the USC School of Medicine and the lead doctor on Dickerson’s trial. Johnson asked him for permission to test the algorithm on Dickerson while she had Liu’s wires in her hippocampus—in between Liu’s own work sessions, of course. As it happened, Liu had dreamed about expanding human powers with technology ever since he got obsessed with The Six Million Dollar Man as a kid. He helped Johnson get Dickerson’s consent and convinced USC’s institutional research board to approve the experiment. At the end of 2016, Johnson got the green light. He was ready to start his first human trial.

In the hospital room, Dickerson is waiting for the experiments to begin, and I ask her how she feels about being a human lab rat.

“If I’m going to be here,” she says, “I might as well do something useful.”

Useful? This starry-eyed dream of cyborg supermen? “You know he’s trying to make humans smarter, right?”

“Isn’t that cool?” she answers.

Over by the computers, I ask one of the scientists about the multi­colored grid on the screen. “Each one of these squares is an electrode that’s in her brain,” one says. Every time a neuron close to one of the wires in Dickerson’s brain fires, he explains, a pink line will jump in the relevant box.

Johnson’s team is going to start with simple memory tests. “You’re going to be shown words,” the scientist explains to her. “Then there will be some math problems to make sure you’re not rehearsing the words in your mind. Try to remember as many words as you can.”

One of the scientists hands Dickerson a computer tablet, and everyone goes quiet. Dickerson stares at the screen to take in the words. A few minutes later, after the math problem scrambles her mind, she tries to remember what she’d read. “Smoke … egg … mud … pearl.”

Next, they try something much harder, a group of memories in a sequence. As one of Kernel’s scientists explains to me, they can only gather so much data from wires connected to 30 or 40 neurons. A single face shouldn’t be too hard, but getting enough data to reproduce memories that stretch out like a scene in a movie is probably impossible.

Sitting by the side of Dickerson’s bed, a Kernel scientist takes on the challenge. “Could you tell me the last time you went to a restaurant?”

“It was probably five or six days ago,” Dickerson says. “I went to a Mexican restaurant in Mission Hills. We had a bunch of chips and salsa.”

He presses for more. As she dredges up other memories, another Kernel scientist hands me a pair of headphones connected to the computer bank. All I hear at first is a hissing sound. After 20 or 30 seconds go by I hear a pop.

“That’s a neuron firing,” he says.

As Dickerson continues, I listen to the mysterious language of the brain, the little pops that move our legs and trigger our dreams. She remembers a trip to Costco and the last time it rained, and I hear the sounds of Costco and rain.

When Dickerson’s eyelids start sinking, the medical team says she’s had enough and Johnson’s people start packing up. Over the next few days, their algorithm will turn Dickerson’s synaptic activity into code. If the codes they send back into Dickerson’s brain make her think of dipping a few chips in salsa, Johnson might be one step closer to reprogramming the operating system of the world.

But look, there’s another banana peel­—after two days of frantic coding, Johnson’s team returns to the hospital to send the new code into Dickerson’s brain. Just when he gets word that they can get an early start, a message arrives: It’s over. The experiment has been placed on “administrative hold.” The only reason USC would give in the aftermath was an issue between Johnson and Berger. Berger would later tell me he had no idea the experiment was under way and that Johnson rushed into it without his permission. Johnson said he is mystified by Berger’s accusations. “I don’t know how he could not have known about it. We were working with his whole lab, with his whole team.” The one thing they both agree on is that their relationship fell apart shortly afterward, with Berger leaving the company and taking his algorithm with him. He blames the break entirely on Johnson. “Like most investors, he wanted a high rate of return as soon as possible. He didn’t realize he’d have to wait seven or eight years to get FDA approval—I would have thought he would have looked that up.” But Johnson didn’t want to slow down. He had bigger plans, and he was in a hurry.

Eight months later, I go back to California to see where Johnson has ended up. He seems a little more relaxed. On the whiteboard behind his desk at Kernel’s new offices in Los Angeles, someone’s scrawled a playlist of songs in big letters. “That was my son,” he says. “He interned here this summer.” Johnson is a year into a romance with Taryn Southern, a charismatic 31-year-old performer and film producer. And since his break with Berger, Johnson has tripled Kernel’s staff—he’s up to 36 employees now—adding experts in fields like chip design and computational neuroscience. His new science adviser is Ed Boyden, the director of MIT’s Synthetic Neurobiology Group and a superstar in the neuroscience world. Down in the basement of the new office building, there’s a Dr. Frankenstein lab where scientists build prototypes and try them out on glass heads.

When the moment seems right, I bring up the purpose of my visit. “You said you had something to show me?”

Johnson hesitates. I’ve already promised not to reveal certain sensitive details, but now I have to promise again. Then he hands me two small plastic display cases. Inside, two pairs of delicate twisty wires rest on beds of foam rubber. They look scientific but also weirdly biological, like the antennae of some futuristic bug-bot.

I’m looking at the prototypes for Johnson’s brand-new neuromodulator. On one level, it’s just a much smaller version of the deep brain stimulators and other neuromodulators currently on the market. But unlike a typical stimulator, which just fires pulses of electricity, Johnson’s is designed to read the signals that neurons send to other neurons—and not just the 100 neurons the best of the current tools can harvest, but perhaps many more. That would be a huge advance in itself, but the implications are even bigger: With Johnson’s neuromodulator, scientists could collect brain data from thousands of patients, with the goal of writing precise codes to treat a variety of neurological diseases.

In the short term, Johnson hopes his neuromodulator will help him “optimize the gold rush” in neurotechnology—financial analysts are forecasting a $27 billion market for neural devices within six years, and countries around the world are committing billions to the escalating race to decode the brain. In the long term, Johnson believes his signal-reading neuromodulator will advance his bigger plans in two ways: (1) by giving neuroscientists a vast new trove of data they can use to decode the workings of the brain and (2) by generating the huge profits Kernel needs to launch a steady stream of innovative and profitable neural tools, keeping the company both solvent and plugged into every new neuroscience breakthrough. With those two achievements in place, Johnson can watch and wait until neuroscience reaches the level of sophistication he needs to jump-start human evolution with a mind-enhancing neuroprosthesis.

Liu, the neurologist with the Six Million Dollar Man dreams, compares Johnson’s ambition to flying. “Going back to Icarus, human beings have always wanted to fly. We don’t grow wings, so we build a plane. And very often these solutions will have even greater capabilities than the ones nature created—no bird ever flew to Mars.” But now that humanity is learning how to reengineer its own capabilities, we really can choose how we evolve. “We have to wrap our minds around that. It’s the most revolutionary thing in the world.”

The crucial ingredient is the profit motive, which always drives rapid innovation in science. That’s why Liu thinks Johnson could be the one to give us wings. “I’ve never met anyone with his urgency to take this to market,” he says.

When will this revolution arrive? “Sooner than you think,” Liu says.

Now we’re back where we began. Is Johnson a fool? Is he just wasting his time and fortune on a crazy dream? One thing is certain: Johnson will never stop trying to optimize the world. At the pristine modern house he rents in Venice Beach, he pours out idea after idea. He even took skepticism as helpful information—when I tell him his magic neuroprosthesis sounds like another version of the Mormon heaven, he’s delighted.

“Good point! I love it!”

He never has enough data. He even tries to suck up mine. What are my goals? My regrets? My pleasures? My doubts?

Every so often, he pauses to examine my “constraint program.”

“One, you have this biological disposition of curiosity. You want data. And when you consume that data, you apply boundaries of meaning-making.”

“Are you trying to hack me?” I ask.

Not at all, he says. He just wants us to share our algorithms. “That’s the fun in life,” he says, “this endless unraveling of the puzzle. And I think, ‘What if we could make the data transfer rate a thousand times faster? What if my consciousness is only seeing a fraction of reality? What kind of stories would we tell?’ ”

In his free time, Johnson is writing a book about taking control of human evolution and looking on the bright side of our mutant humanoid future. He brings this up every time I talk to him. For a long time I lumped this in with his dreamy ideas about reprogramming the operating system of the world: The future is coming faster than anyone thinks, our glorious digital future is calling, the singularity is so damn near that we should be cheering already—a spiel that always makes me want to hit him with a copy of the Unabomber Manifesto.

But his urgency today sounds different, so I press him on it: “How would you respond to Ted Kaczynski’s fears? The argument that technology is a cancerlike development that’s going to eat itself?”

“I would say he’s potentially on the wrong side of history.”

“Yeah? What about climate change?”

“That’s why I feel so driven,” he answered. “We’re in a race against time.”

He asks me for my opinion. I tell him I think he’ll still be working on cyborg brainiacs when the starving hordes of a ravaged planet destroy his lab looking for food—and for the first time, he reveals the distress behind his hope. The truth is, he has the same fear. The world has gotten way too complex, he says. The financial system is shaky, the population is aging, robots want our jobs, artificial intelligence is catching up, and climate change is coming fast. “It just feels out of control,” he says.

He’s invoked these dystopian ideas before, but only as a prelude to his sales pitch. This time he’s closer to pleading. “Why wouldn’t we embrace our own self-directed evolution? Why wouldn’t we just do everything we can to adapt faster?”

I turn to a more cheerful topic. If he ever does make a neuroprosthesis to revolutionize how we use our brain, which superpower would he give us first? Telepathy? Group minds? Instant kung fu?

He answers without hesitation. Because our thinking is so constrained by the familiar, he says, we can’t imagine a new world that isn’t just another version of the world we know. But we have to imagine something far better than that. So he’d try to make us more creative—that would put a new frame on everything.

Ambition like that can take you a long way. It can drive you to try to reach the South Pole when everyone says it’s impossible. It can take you up Mount Kilimanjaro when you’re close to dying and help you build an $800 million company by the time you’re 36. And Johnson’s ambitions drive straight for the heart of humanity’s most ancient dream: For operating system, substitute enlightenment.

By hacking our brains, he wants to make us one with everything.


by Jason Daley

Fiinding bones from early humans and their ancestors is difficult and rare—often requiring scientists to sort through the sediment floor of caves in far-flung locations. But modern advances in technology could completely transform the field. As Gina Kolta reports for The New York Times, a new study documents a method to extract and sequence fragments of hominid DNA from samples of cave dirt.

The study, published this week in the journal Science, could completely change the type of evidence available to study our ancestral past. Researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, collected 85 sediment samples from seven archeological sites in Belgium, Croatia, France, Russia and Spain, covering a span of time from 550,000 to 14,000 years ago.

As Lizzie Wade at Science reports, when the team first sequenced the DNA from the sediments, they were overwhelmed. There are trillions of fragments of DNA in a teaspoon of dirt, mostly material from other mammals, including woolly mammoth, woolly rhinoceroses, cave bears and cave hyenas. To cut through the clutter and examine only hominid DNA, they created a molecular “hook” made from the mitochondrial DNA of modern humans. The hook was able to capture DNA fragments that most resembled itself, pulling out fragments from Neanderthals at four sites, including in sediment layers where bones or tools from the species were not present. They also found more DNA from Denisovans, an enigmatic human ancestor found only in single cave in Russia.

“It’s a great breakthrough,” Chris Stringer, anthropologist at the Natural History Museum in London tells Wade. “Anyone who’s digging cave sites from the Pleistocene now should put [screening sediments for human DNA] on their list of things that they must do.”

So how did the DNA get there? The researchers can’t say exactly, but it wouldn’t be too difficult. Humans shed DNA constantly. Any traces of urine, feces, spit, sweat, blood or hair would all contain minute bits of DNA. These compounds actually bind with minerals in bone, and likely did the same with minerals in the soil, preserving it, reports Charles Q. Choi at LiveScience.

There’s another—slightly scarier—option for the DNA’s origins. The researchers found a lot of hyena DNA at the study sites, Matthias Meyer, an author of the study tells Choi. “Maybe the hyenas were eating human corpses outside the caves, and went into the caves and left feces there, and maybe entrapped in the hyena feces was human DNA.”

The idea of pulling ancient DNA out of sediments is not new. As Kolta reports, researchers have previously successfully recovered DNA fragments of prehistoric mammals from a cave in Colorado. But having a technique aimed at finding DNA from humans and human ancestors could revolutionize the field. Wade points out that such a technique might have helped produce evidence for the claim earlier this week that hominids were in North America 130,000 years ago.

DNA analysis of sediments might eventually become a routine part of archeology, similar to radio carbon dating, says Svante Pääbo, director of the Evolutionary Genetics department at the Max Planck Institute for Evolutionary Anthropology, in the press release. The technique could also allow researchers to start searching for traces of early hominids at sites outside of caves.

“If it worked, it would provide a much richer picture of the geographic distribution and migration patterns of ancient humans, one that was not limited by the small number of bones that have been found,” David Reich, Harvard geneticist tells Kolta. “That would be a magical thing to do.”

As Wade reports, the technique could also solve many mysteries, including determining whether certain tools and sites were created by humans or Neanderthals. It could also reveal even more hominid species that we have not found bones for, creating an even more complete human family tree.

Read more:

by Jaymi Heimbuch

When a flock of geese fly into the air and a hunter takes aim, which bird is most likely to drop from the sky? A new study published in the journal Biology Letters shows that those birds with larger brains relative to their body size are less likely to be shot by hunters.

PhysOrg reports:

The researchers found that those birds with smaller brains (relative to the size of their bodies) were more likely to be shot and catalogued—as were males and larger birds in general. The team looked at a variety of factors such as organ size, body mass, gender, species, color, etc., and found one factor that stood out very clearly from the rest—birds with larger brains were 30 times less likely to be shot and killed. This, the team suggests, indicates that hunting is very likely having an evolutionary impact on animals that are hunted by humans. They do not believe that hunters are specifically targeting smaller species, it’s more likely that those with larger brains have learned to be wary of humans.

Brain size is of course not the only possible factor for which bird ends up on a hunter’s dinner table. But the ability to distinguish danger with more clarity than your compatriots certainly helps, and the researchers point out that brain size might be part of that ability.

By Ann Gibbons

Humans did not evolve alone. Tens of trillions of microbes have followed us on our journey from prehistoric ape, evolving with us along the way, according to a new study. But the work also finds that we’ve lost some of the ancient microbes that still inhabit our great ape cousins, which could explain some human diseases and even obesity and mental disorders.

Researchers have known for some time that humans and the other great apes harbor many types of bacteria, especially in their guts, a collection known as the microbiome. But where did these microbes come from: our ancient ancestors, or our environment? A study of fecal bacteria across all mammals suggested that the microbes are more likely to be inherited than acquired from the environment. But other studies have found that diet plays a major role in shaping the bacteria in our guts.

To solve the mystery, Andrew Moeller turned to wild apes. As part of his doctoral dissertation, the evolutionary biologist, now a postdoc at the University of California, Berkeley, studied gut bacteria isolated from fecal samples from 47 chimpanzees from Tanzania, 24 bonobos from the Democratic Republic of the Congo, 24 gorillas from Cameroon, and 16 humans from Connecticut. In these samples, he and colleagues at the University of Texas (UT), Austin, compared the DNA sequences of a single rapidly evolving gene that is common in the gut bacteria in apes, including humans. They then sorted the different DNA gene sequences into family trees.

It turns out that most of our gut microbes have been evolving with us for a long time. Moeller found that two of three major families of gut bacteria in apes and humans trace their origins to a common ancestor more than 15 million years ago, not primarily to bugs picked up from their environment. But as the different species of apes diverged from this ancestor, their gut bacteria also split into new strains, and coevolved in parallel (a process known as cospeciation) to adapt to differences in the diets, habitats, and diseases in the gastrointestinal tracts of their hosts, the team reports today in Science. Today, these microbes are finely adapted to help train our immune systems, guide the development of our intestines, and even modulate our moods and behaviors.

“It’s surprising that our gut microbes, which we could get from many sources in the environment, have actually been coevolving inside us for such a long time,” says project leader Howard Ochman, an evolutionary biologist at UT Austin.

After the ape species diverged, some also lost distinct strains of bacteria that persisted in other primates, likely another sign of adaptation in the host, the team found.

In a final experiment, the researchers probed deeper into the human microbiome. They compared the same DNA sequence they had analyzed in all of the apes, but this time between the people from Connecticut and people from Malawi. They found that the bacterial strains from these Africans diverged from those of the Americans about 1.7 million years ago, which corresponds with the earliest exodus of human ancestors out of Africa. This suggests that gut bacteria can be used to trace early human and animal migrations, Moeller says. Interestingly, the Americans lacked some of the strains of bacteria found in Malawians—and in gorillas and chimps—which fits with the general reduction in gut microbiome diversity that has been observed in people in industrialized societies, perhaps because of changes in diet and the use of antibiotics.

The work “represents a significant step in understanding human microbiota coevolutionary history,” says Justin Sonnenburg of Stanford University in Palo Alto, California, who was not involved with the research. “It elegantly shows that gut microbes are passed vertically, between generations over millions of years.” Microbiologist Martin Blaser of New York University in New York City agrees: “The path of transmission was from mom apes to baby apes for hundreds of thousands of generations at least.”

But the extinction of some strains of bacteria that persist in other apes but not humans raises a red flag for our health. “What happens if a human mom takes antibiotic when she’s pregnant? What happens if she takes it at the moment of delivery?” Blaser asks.

“We are coming to understand how fundamental our gut microbes are for health,” Sonnenburg says. “These findings have huge implications for how we should pursue understanding what a truly healthy microbiome looks like.”

Thanks to Kebmodee for bringing this to the It’s Interesting community.

Humans use a unique call to request help from honeyguide birds, and the birds also ‘actively recruit’ human partners. This is two-way teamwork, scientists say, a rarity between people and wildlife.

By Russell McLendon


When a human makes that sound in Mozambique’s Niassa National Reserve, a wild bird species instinctively knows what to do. The greater honeyguide responds by leading the human to a wild beehive, where both can feast on honey and wax. The bird does this without any training from people, or even from its own parents.

This unique relationship pre-dates any recorded history, and likely evolved over hundreds of thousands of years. It’s a win-win, since the birds help humans find honey, and the humans (who can subdue a beehive more easily than the 1.7-ounce birds can) leave behind beeswax as payment for their avian informants.

While this ancient partnership is well-known to science, a new study, published July 22 in the journal Science, reveals incredible details about how deep the connection has become. Honeyguides “actively recruit appropriate human partners,” the study’s authors explain, using a special call to attract people’s attention. Once that works, they fly from tree to tree to indicate the direction of a beehive.

Not only do honeyguides use calls to seek human partners, but humans also use specialized calls to summon the birds. Honeyguides attach specific meaning to “brrr-hm,” the authors say, a rare case of communication and teamwork between humans and wild animals. We’ve trained lots of domesticated animals to work with us, but for wildlife to do so voluntarily — and instinctively — is pretty wild.

Here’s an example of what the “brrr-hm” call sounds like:

“What’s remarkable about the honeyguide-human relationship is that it involves free-living wild animals whose interactions with humans have probably evolved through natural selection, probably over the course of hundreds of thousands of years,” says lead author Claire Spottiswoode, a zoologist at the University of Cambridge.

“[W]e’ve long known that people can increase their rate of finding bees’ nests by collaborating with honeyguides, sometimes following them for over a kilometer,” Spottiswoode explains in a statement. “Keith and Colleen Begg, who do wonderful conservation work in northern Mozambique, alerted me to the Yao people’s traditional practice of using a distinctive call which they believe helps them to recruit honeyguides. This was instantly intriguing — could these calls really be a mode of communication between humans and a wild animal?”

To answer that question, Spottiswoode went to Niassa National Reserve, a vast wildlife refuge larger than Switzerland. With the help of honey hunters from the local Yao community, she tested whether the birds can distinguish “brrr-hm” — a sound passed down from generation to generation of Yao hunters — from other human vocalizations, and if they know to respond accordingly.

She made audio recordings of the call, along with two “control” sounds — arbitrary words spoken by the Yao hunters, and the calls of another bird species. When she played all three recordings in the wild, the difference was clear: Honeyguides proved much more likely to answer the “brrr-hm” call than either of the other sounds.

“The traditional ‘brrr-hm’ call increased the probability of being guided by a honeyguide from 33 percent to 66 percent, and the overall probability of being shown a bees’ nest from 16 percent to 54 percent compared to the control sounds,” Spottiswoode says. “In other words, the ‘brrr-hm’ call more than tripled the chances of a successful interaction, yielding honey for the humans and wax for the bird.”

The researchers released this video, which includes footage from their experiments

This is known as mutualism, and while lots of animals have evolved mutualistic relationships, it’s very rare between humans and wildlife. People also recruit honeyguides in other parts of Africa, the study’s authors note, using different sounds like the melodious whistle of Hadza honey hunters in Tanzania. But aside from that, the researchers say the only comparable example involves wild dolphins who chase schools of mullet into anglers’ nets, catching more fish for themselves in the process.

“It would be fascinating to know whether dolphins respond to special calls made by fishermen,” Spottiswoode says.

The researchers also say they’d like to study if honeyguides learned “language-like variation in human signals” across Africa, helping the birds identify good partners among the local human population. But however it began, we know the skill is now instinct, requiring no training from people. And since honeyguides reproduce like cuckoos — laying eggs in other species’ nests, thus tricking them into raising honeyguide chicks — we know they don’t learn it from their parents, either.

This human-honeyguide relationship isn’t just fascinating; it’s also threatened, fading away in many places along with other ancient cultural practices. By shedding new light on it, Spottiswoode hopes her research can also help preserve it.

“Sadly, the mutualism has already vanished from many parts of Africa,” she says. “The world is a richer place for wildernesses like Niassa where this astonishing example of human-animal cooperation still thrives.”


by Pallab Ghosh
Science correspondent, BBC News, Johannesburg

Scientists have discovered a new human-like species in a burial chamber deep in a cave system in South Africa. The discovery of 15 partial skeletons is the largest single discovery of its type in Africa.

The researchers claim that the discovery will change ideas about our human ancestors.

The studies which have been published in the journal Elife also indicate that these individuals were capable of ritualistic behaviour.

The species, which has been named naledi, has been classified in the grouping, or genus, Homo, to which modern humans belong.

The researchers who made the find have not been able to find out how long ago these creatures lived – but the scientist who led the team, Prof Lee Berger, told BBC News that he believed they could be among the first of our kind (genus Homo) and could have lived in Africa up to three million years ago.

Like all those working in the field, he is at pains to avoid the term “missing link”. Prof Berger says naledi could be thought of as a “bridge” between more primitive bipedal primates and humans.

“We’d gone in with the idea of recovering one fossil. That turned into multiple fossils. That turned into the discovery of multiple skeletons and multiple individuals.

“And so by the end of that remarkable 21-day experience, we had discovered the largest assemblage of fossil human relatives ever discovered in the history of the continent of Africa. That was an extraordinary experience.”

Prof Chris Stringer of the Natural History Museum said naledi was “a very important discovery”.

“What we are seeing is more and more species of creatures that suggests that nature was experimenting with how to evolve humans, thus giving rise to several different types of human-like creatures originating in parallel in different parts of Africa. Only one line eventually survived to give rise to us,” he told BBC News.

I went to see the bones which are kept in a secure room at Witwatersrand University. The door to the room looks like one that would seal a bank vault. As Prof Berger turned the large lever on the door, he told me that our knowledge of very early humans is based on partial skeletons and the occasional skull.

he haul of 15 partial skeletons includes both males and females of varying ages – from infants to elderly. The discovery is unprecedented in Africa and will shed more light on how the first humans evolved.

“We are going to know everything about this species,” Prof Berger told me as we walked over to the remains of H. naledi.

“We are going to know when its children were weaned, when they were born, how they developed, the speed at which they developed, the difference between males and females at every developmental stage from infancy, to childhood to teens to how they aged and how they died.”

I was astonished to see how well preserved the bones were. The skull, teeth and feet looked as if they belonged to a human child – even though the skeleton was that of an elderly female.
Its hand looked human-like too, up to its fingers which curl around a bit like those of an ape.

Homo naledi is unlike any primitive human found in Africa. It has a tiny brain – about the size of a gorilla’s and a primitive pelvis and shoulders. But it is put into the same genus as humans because of the more progressive shape of its skull, relatively small teeth, characteristic long legs and modern-looking feet.

“I saw something I thought I would never see in my career,” Prof Berger told me.

“It was a moment that 25 years as a paleoanthropologist had not prepared me for.”

One of the most intriguing questions raised by the find is how the remains got there.

I visited the site of the find, the Rising Star cave, an hour’s drive from the university in an area known as the Cradle of Humankind. The cave leads to a narrow underground tunnel through which some of Prof Berger’s team crawled in an expedition funded by the National Geographic Society.

Small women were chosen because the tunnel was so narrow. They crawled through darkness lit only by their head torches on a precarious 20 minute-long journey to find a chamber containing hundreds of bones.

Among them was Marina Elliott. She showed me the narrow entrance to the cave and then described how she felt when she first saw the chamber.

“The first time I went to the excavation site I likened it to the feeling that Howard Carter must have had when he opened Tutankhamen’s tomb – that you are in a very confined space and then it opens up and all of a sudden all you can see are all these wonderful things – it was incredible,” she said.

Ms Elliott and her colleagues believe that they have found a burial chamber. The Homo naledi people appear to have carried individuals deep into the cave system and deposited them in the chamber – possibly over generations.

If that is correct, it suggests naledi was capable of ritual behaviour and possibly symbolic thought – something that until now had only been associated with much later humans within the last 200,000 years.

Prof Berger said: “We are going to have to contemplate some very deep things about what it is to be human. Have we been wrong all along about this kind of behaviour that we thought was unique to modern humans?

“Did we inherit that behaviour from deep time and is it something that (the earliest humans) have always been able to do?”

Prof Berger believes that the discovery of a creature that has such a mix of modern and primitive features should make scientists rethink the definition of what it is to be human – so much so that he himself is reluctant to describe naledi as human.

Other researchers working in the field, such as Prof Stringer, believe that naledi should be described as a primitive human. But he agrees that current theories need to be re-evaluated and that we have only just scratched the surface of the rich and complex story of human evolution.

Tastes are a privilege. The oral sensations not only satisfy foodies, but also on a primal level, protect animals from toxic substances. Yet cetaceans—whales and dolphins—may lack this crucial ability, according to a new study. Mutations in a cetacean ancestor obliterated their basic machinery for four of the five primary tastes, making them the first group of mammals to have lost the majority of this sensory system.

The five primary tastes are sweet, bitter, umami (savory), sour, and salty. These flavors are recognized by taste receptors—proteins that coat neurons embedded in the tongue. For the most part, taste receptor genes present across all vertebrates.

Except, it seems, cetaceans. Researchers uncovered a massive loss of taste receptors in these animals by screening the genomes of 15 species. The investigation spanned the two major lineages of cetaceans: Krill-loving baleen whales—such as bowheads and minkes—were surveyed along with those with teeth, like bottlenose dolphins and sperm whales.

The taste genes weren’t gone per se, but were irreparably damaged by mutations, the team reports online this month in Genome Biology and Evolution. Genes encode proteins, which in turn execute certain functions in cells. Certain errors in the code can derail protein production—at which point the gene becomes a “pseudogene” or a lingering shell of a trait forgotten. Identical pseudogene corpses were discovered across the different cetacean species for sweet, bitter, umami, and sour taste receptors. Salty tastes were the only exception.

“The loss of bitter taste is a complete surprise, because natural toxins typically taste bitter,” says zoologist Huabin Zhao of Wuhan University in China who led the study. All whales likely descend from raccoon-esque raoellids, a group of herbivorous land mammals that transitioned to the sea where they became fish eaters. Plants range in flavors—from sugary apples to tart, poisonous rhubarb leaves—and to survive, primitive animals learned the taste cues that signal whether food is delicious or dangerous. Based on the findings, taste dissipated after this common ancestor became fully aquatic—53 million years ago—but before the group split 36 million years ago into toothed and baleen whales.

“Pseudogenes arise when a trait is no longer needed,” says evolutionary biologist Jianzhi Zhang of the University of Michigan, Ann Arbor, who was not involved in the study. “So it still raises the question as to why whales could afford to lose four of the five primary tastes.” The retention of salty taste receptors suggests that they have other vital roles, such as maintaining sodium levels and blood pressure.

But dulled taste perception might be dangerous if noxious substances spill into the water. Orcas have unwittingly migrated into oil spills, while algal toxins created by fertilizer runoff consistently seep into the fish prey of dolphins living off the Florida coast.

“When you have a sense of taste, it dictates whether you swallow or not,” says Danielle Reed, a geneticist at the Monell Chemical Senses Center in Philadelphia, Pennsylvania. She was not involved with the current work, but co-authored a 2012 paper that found the first genetic inklings that umami and sweet taste receptors were missing in cetaceans, albeit in only one species—bottlenose dolphins.

Flavors are typically released by chewing, but cetaceans tend to swallow their food whole. “The message seems clear. If you don’t chew your food and prefer swallowing food whole, then taste really becomes irrelevant,” Reed says.

Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.