Your animal life is over. Machine life has begun. The road to immortality

In California, radical scientists and billionaire backers think the technology to extend life by uploading minds to exist separately from the body is only a few years away

Heres what happens. You are lying on an operating table, fully conscious, but rendered otherwise insensible, otherwise incapable of movement. A humanoid machine appears at your side, bowing to its task with ceremonial formality. With a brisk sequence of motions, the machine removes a large panel of bone from the rear of your cranium, before carefully laying its fingers, fine and delicate as a spiders legs, on the viscid surface of your brain. You may be experiencing some misgivings about the procedure at this point. Put them aside, if you can.

Youre in pretty deep with this thing; theres no backing out now. With their high-resolution microscopic receptors, the machine fingers scan the chemical structure of your brain, transferring the data to a powerful computer on the other side of the operating table. They are sinking further into your cerebral matter now, these fingers, scanning deeper and deeper layers of neurons, building a three-dimensional map of their endlessly complex interrelations, all the while creating code to model this activity in the computers hardware. As thework proceeds, another mechanical appendage less delicate, less careful removes the scanned material to a biological waste container for later disposal. This is material you will no longer be needing.

At some point, you become aware that you are no longer present in your body. You observe with sadness, or horror, or detached curiosity the diminishing spasms of that body on the operating table, the last useless convulsions of a discontinued meat.

The animal life is over now. The machine life has begun.

This, more or less, is the scenario outlined by Hans Moravec, a professor of cognitive robotics at Carnegie Mellon, in his 1988 book Mind Children: The Future of Robot and Human Intelligence. It is Moravecs conviction that the future of the human species will involve a mass-scale desertion of our biological bodies, effected by procedures of this kind. Its a belief shared by many transhumanists, a movement whose aim is to improve our bodies and minds to the point where we become something other and better than the animals we are. Ray Kurzweil, for one, is a prominent advocate of the idea of mind-uploading. An emulation of the human brain running on an electronic system, he writes in The Singularity Is Near, would run much faster than our biological brains. Although human brains benefit from massive parallelism (on the order of 100 trillion interneuronal connections, all potentially operating simultaneously), the rest time of the connections is extremely slow compared to contemporary electronics. The technologies required for such an emulation sufficiently powerful and capacious computers and sufficiently advanced brainscanning techniques will be available, he announces, by the early 2030s.

And this, obviously, is no small claim. We are talking about not just radically extended life spans, but also radically expanded cognitive abilities. We are talking about endless copies and iterations of the self. Having undergone a procedure like this, you would exist to the extent you could meaningfully be said to exist at all as an entity of unbounded possibilities.

I was introduced to Randal Koene at a Bay Area transhumanist conference. He wasnt speaking at the conference, but had come along out of personal interest. A cheerfully reserved man in his early 40s, he spoke in the punctilious staccato of a non-native English speaker who had long mastered the language. As we parted, he handed me his business card and much later that evening Iremoved it from my wallet and had a proper look at it. The card was illustrated with a picture of a laptop, on whose screen was displayed a stylised image of a brain. Underneath was printed what seemed to me an attractively mysterious message: Carboncopies: Realistic Routes to Substrate Independent Minds. Randal A Koene, founder.

I took out my laptop and went to the website of Carboncopies, which I learned was a nonprofit organisation with a goal of advancing the reverse engineering of neural tissue and complete brains, Whole Brain Emulation and development of neuroprostheses that reproduce functions of mind, creating what we call Substrate Independent Minds. This latter term, I read, was the objective to be able to sustain person-specific functions of mind and experience in many different operational substrates besides the biological brain. And this, I further learned, was a process analogous to that by which platform independent code can be compiled and run on many different computing platforms.

It seemed that I had met, without realising it, a person who was actively working toward the kind of brain-uploading scenario that Kurzweil had outlined in The Singularity Is Near. And this was a person I needed to get to know.

Randal
Randal Koene: It wasnt like I was walking into labs, telling people I wanted to upload human minds to computers.

Koene was an affable and precisely eloquent man and his conversation was unusually engaging for someone so forbiddingly intelligent and who worked in so rarefied a field as computational neuroscience; so, in his company, I often found myself momentarily forgetting about the nearly unthinkable implications of the work he was doing, the profound metaphysical weirdness of the things he was explaining to me. Hed be talking about some tangential topic his happily cordial relationship with his ex-wife, say, or the cultural differences between European and American scientific communities and Id remember with a slow, uncanny suffusion of unease that his work, were it to yield the kind of results he is aiming for, would amount to the most significant event since the evolution of Homo sapiens. The odds seemed pretty long from where I was standing, but then again, I reminded myself, the history of science was in many ways an almanac of highly unlikely victories.

One evening in early spring, Koene drove down to San Francisco from the North Bay, where he lived and worked in a rented ranch house surrounded by rabbits, to meet me for dinner in a small Argentinian restaurant on Columbus Avenue. The faint trace of an accent turned out to be Dutch. Koene was born in Groningen and had spent most of his early childhood in Haarlem. His father was a particle physicist and there were frequent moves, including a two-year stint in Winnipeg, as he followed his work from one experimental nuclear facility to the next.

Now a boyish 43, he had lived in California only for the past five years, but had come to think of it as home, or the closest thing to home hed encountered in the course of a nomadic life. And much of this had to do with the culture of techno-progressivism that had spread outward from its concentrated origins in Silicon Valley and come to encompass the entire Bay Area, with its historically high turnover of radical ideas. It had been a while now, he said, since hed described his work to someone, only for them to react as though he were making a misjudged joke or simply to walk off mid-conversation.

In his early teens, Koene began to conceive of the major problem with the human brain in computational terms: it was not, like a computer, readable and rewritable. You couldnt get in there and enhance it, make it run more efficiently, like you could with lines of code. You couldnt just speed up a neuron like you could with a computer processor.

Around this time, he read Arthur C Clarkes The City and the Stars, a novel set a billion years from now, in which the enclosed city of Diaspar is ruled by a superintelligent Central Computer, which creates bodies for the citys posthuman citizens and stores their minds in its memory banks at the end of their lives, for purposes of reincarnation. Koene saw nothing in this idea of reducing human beings to data that seemed to him implausible and felt nothing in himself that prevented him from working to bring it about. His parents encouraged him in this peculiar interest and the scientific prospect of preserving human minds in hardware became a regular topic of dinnertime conversation.

Computational neuroscience, which drew its practitioners not from biology but from the fields of mathematics and physics, seemed to offer the most promising approach to the problem of mapping and uploading the mind. It wasnt until he began using the internet in the mid-1990s, though, that he discovered a loose community of people with an interest in the same area.

As a PhD student in computational neuroscience at Montreals McGill University, Koene was initially cautious about revealing the underlying motivation for his studies, for fear of being taken for a fantasist or an eccentric.

I didnt hide it, as such, he said, but it wasnt like I was walking into labs, telling people I wanted to upload human minds to computers either. Id work with people on some related area, like the encoding of memory, with a view to figuring out how that might fit into an overall road map for whole brain emulation.

Having worked for a while at Halcyon Molecular, a Silicon Valley gene-sequencing and nanotechnology startup funded by Peter Thiel, he decided to stay in the Bay Area and start his own nonprofit company aimed at advancing the cause to which hed long been dedicated: carboncopies

Koenes decision was rooted in the very reason he began pursuing that work in the first place: an anxious awareness of the small and diminishing store of days that remained to him. If hed gone the university route, hed have had to devote most of his time, at least until securing tenure, to projects that were at best tangentially relevant to his central enterprise. The path he had chosen was a difficult one for a scientist and he lived and worked from one small infusion of private funding to the next.

But Silicon Valleys culture of radical techno-optimism had been its own sustaining force for him, and a source of financial backing for a project that took its place within the wildly aspirational ethic of that cultural context. There were people there or thereabouts, wealthy and influential, for whom a future in which human minds might be uploaded to computers was one to be actively sought, a problem to be solved, disruptively innovated, by the application of money.

Transcendence
Brainchild of the movies: in Transcendence (2014), scientist Will Caster, played by Johnny Depp, uploads his mind to a computer program with dangerous results.

One such person was Dmitry Itskov, a 36-year-old Russian tech multimillionaire and founder of the 2045 Initiative, an organisationwhose stated aim was to create technologies enabling the transfer of an individuals personality to a more advanced nonbiological carrier, and extending life, including to the point of immortality. One of Itskovs projects was the creation of avatars artificial humanoid bodies that would be controlled through brain-computer interface, technologies that would be complementary with uploaded minds. He had funded Koenes work with Carboncopies and in 2013 they organised a conference in New York called Global Futures 2045, aimed, according to its promotional blurb, at the discussion of a new evolutionary strategy for humanity.

When we spoke, Koene was working with another tech entrepreneur named Bryan Johnson, who had sold his automated payment company to PayPal a couple of years back for $800m and who now controlled a venture capital concern called the OS Fund, which, I learned from its website, invests in entrepreneurs working towards quantum leap discoveries that promise to rewrite the operating systems of life. This language struck me as strange and unsettling in a way that revealed something crucial about the attitude toward human experience that was spreading outward from its Bay Area centre a cluster of software metaphors that had metastasised into a way of thinking about what it meant to be a human being.

And it was the sameessential metaphor that lay at the heart of Koenes project: the mind as a piece of software, an application running on the platform of flesh. When he used the term emulation, he was using it explicitly to evoke the sense in which a PCs operating system could be emulated on a Mac, as what he called platform independent code.

The relevant science for whole brain emulation is, as youd expect, hideously complicated, and its interpretation deeply ambiguous, but if I can risk a gross oversimplification here, I will say that it is possible to conceive of the idea as something like this: first, you scan the pertinent information in a persons brain the neurons, the endlessly ramifying connections between them, the information-processing activity of which consciousness is seen as a byproduct through whatever technology, or combination of technologies, becomes feasible first (nanobots, electron microscopy, etc). That scan then becomes a blueprint for the reconstruction of the subject brains neural networks, which is then converted into a computational model. Finally, you emulate all of this on a third-party non-flesh-based substrate: some kind of supercomputer or a humanoid machine designed to reproduce and extend the experience of embodiment something, perhaps, like Natasha Vita-Mores Primo Posthuman.

The whole point of substrate independence, as Koene pointed out to me whenever I asked him what it would be like to exist outside of a human body, and I asked him many times, in various ways was that it would be like no one thing, because there would be no one substrate, no one medium of being. This was the concept transhumanists referred to as morphological freedom the liberty to take any bodily form technology permits.

You can be anything you like, as an article about uploading in Extropy magazine put it in the mid-90s. You can be big or small; you can be lighter than air and fly; you can teleport and walk through walls. You can be a lion or an antelope, a frog or a fly, a tree, a pool, the coat of paint on a ceiling.

What really interested me about this idea was not how strange and far-fetched it seemed (though it ticked those boxes resolutely enough), but rather how fundamentally identifiable it was, how universal. When talking to Koene, I was mostly trying to get to grips with the feasibility of the project and with what it was he envisioned as a desirable outcome. But then we would part company I would hang up the call, or I would take my leave and start walking toward the nearest station and I would find myself feeling strangely affected by the whole project, strangely moved.

Because there was something, in the end, paradoxically and definitively human in this desire for liberation from human form. I found myself thinking often of WB Yeatss Sailing to Byzantium, in which the ageing poet writes of his burning to be free of the weakening body, the sickening heart to abandon the dying animal for the manmade and immortal form of a mechanical bird. Once out of nature, he writes, I shall never take/ My bodily form from any natural thing/ But such a form as Grecian goldsmiths make.

One evening, we were sitting outside a combination bar/laundromat/standup comedy venue in Folsom Street a place with the fortuitous name of BrainWash when I confessed that the idea of having my mind uploaded to some technological substrate was deeply unappealing to me, horrifying even. The effects of technology on my life, even now, were something about which I was profoundly ambivalent; for all I had gained in convenience and connectedness, I was increasingly aware of the extent to which my movements in the world were mediated and circumscribed by corporations whose only real interest was in reducing the lives of human beings to data, as a means to further reducing us to profit.

The content we consumed, the people with whom we had romantic encounters, the news we read about the outside world: all these movements were coming increasingly under the influence of unseen algorithms, the creations of these corporations, whose complicity with government, moreover, had come to seem like the great submerged narrative of our time. Given the world we were living in, where the fragile liberal ideal of the autonomous self was already receding like a half-remembered dream into the doubtful haze of history, wouldnt a radical fusion of ourselves with technology amount, in the end, to a final capitulation of the very idea of personhood?

Koene nodded again and took a sip of his beer.

Hearing you say that, he said, makes it clear that theres a major hurdle there for people. Im more comfortable than you are with the idea, but thats because Ive been exposed to it for so long that Ive just got used to it.

Dmitry
Russian billionaire Dmitry Itskov wants to create technologies enabling the transfer of an individuals personality to a more advanced nonbiological carrier. Photograph: Mary Altaffer/AP

In the weeks and months after I returned from San Francisco, I thought obsessively about the idea of whole brain emulation. One morning, I was at home in Dublin, suffering from both a head cold and a hangover. I lay there, idly considering hauling myself out of bed to join my wife and my son, who were in his bedroom next door enjoying a raucous game of Buckaroo. I realised that these conditions (head cold, hangover) had imposed upon me a regime of mild bodily estrangement. As often happens when Im feeling under the weather, I had a sense of myself as an irreducibly biological thing, an assemblage of flesh and blood and gristle. I felt myself to be an organism with blocked nasal passages, a bacteria-ravaged throat, a sorrowful ache deep within its skull, its cephalon. I was aware of my substrate, in short, because my substrate felt like shit.

And I was gripped by a sudden curiosity as to what, precisely, that substrate consisted of, as to what I myself happened, technically speaking, to be. I reached across for the phone on my nightstand and entered into Google the words What is the human… The first three autocomplete suggestions offered What is The Human Centipede about, and then: What is the human body made of, and then: What is the human condition.

It was the second question I wanted answered at this particular time, as perhaps a back door into the third. It turned out that I was 65% oxygen, which is to say that I was mostly air, mostly nothing. After that, I was composed of diminishing quantities of carbon and hydrogen, of calcium and sulphur and chlorine, and so on down the elemental table. I was also mildly surprised to learn that, like the iPhone I was extracting this information from, I also contained trace elements of copper and iron and silicon.

What a piece of work is a man, I thought, what a quintessence of dust.

Some minutes later, my wife entered the bedroom on her hands and knees, our son on her back, gripping the collar of her shirt tight in his little fists. She was making clip-clop noises as she crawled forward, he was laughing giddily and shouting: Dont buck! Dont buck!

With a loud neighing sound, she arched her back and sent him tumbling gently into a row of shoes by the wall and he screamed in delighted outrage, before climbing up again. None of this, I felt, could be rendered in code. None of this, I felt, could be run on any other substrate. Their beauty was bodily, in the most profound sense, in the saddest and most wonderful sense.

I never loved my wife and our little boy more, I realised, than when I thought of them as mammals. I dragged myself, my animal body, out of bed to join them.

To Be a Machine by Mark OConnell is published by Granta (12.99). To order a copy for 11.04 go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over 10, online orders only. Phone orders min p&p of 1.99

Read more: https://www.theguardian.com/science/2017/mar/25/animal-life-is-over-machine-life-has-begun-road-to-immortality

Biologists Are Figuring Out How Cells Tell Left From Right

In 2009, after she was diagnosed with stage 3 breast cancer, Ann Ramsdell began to search the scientific literature to see if someone with her diagnosis could make a full recovery. Ramsdell, a developmental biologist at the University of South Carolina, soon found something strange: The odds of recovery differed for women who had cancer in the left breast versus the right. Even more surprisingly, she found research suggesting that women with asymmetric breast tissue are more likely to develop cancer.

Quanta Magazine


About

Original storyreprinted with permission from Quanta Magazine, an editorially independent division of theSimons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences


Asymmetry is not readily apparent. Yet below the skin, asymmetric structures are common. Consider how our gut winds its way through the abdominal cavity, sprouting unpaired organs as it goes. Or how our heart, born from two identical structures fused together, twists itself into an asymmetrical pump that can simultaneously push oxygen-rich blood around the body and draw in a new swig from the lungs, all in a heartbeat. The bodys natural asymmetry is crucially important to our well-being. But, as Ramsdell knew, it was all too often ignored.

In her early years as a scientist, Ramsdell never gave asymmetry much thought. But on the day of her dissertation defense, she put a borrowed slide into a projector (this in the days before PowerPoint). The slide was of a chick embryo at the stage where its heart begins to loop to one side. Afterward a colleague asked why she put the slide in backward. Its an embarrassing story, she said, but I had never even thought about the directionality of heart looping. The chicks developing heart could distinguish between left and right, same as ours. She went on to do her postdoctoral research on why the heart loops to one side.

Years later, after her recovery, Ramsdell decided to leave the heart behind and to start looking for asymmetry in the mammary glands of mammals. In marsupials like wallabies and kangaroos, she read, the left and the right glands produce a different kind of milk, geared toward offspring of different ages. But her initial studies of mice proved disappointingtheir left and right mammary glands didnt seem to differ at all.

The wrybill uses its laterally curved bill to reach insect larvae under rounded riverbed stones.Steve Atwood

Then she zoomed in on the genes and proteins that are active in different cells of the breast. There she found strong differences. The left breast, which appears to be more prone to cancer, also tends to have a higher number of unspecialized cells, according to unpublished work thats undergoing peer review. Those allow the breast to repair damaged tissue, but since they have a higher capacity to divide, they can also be involved in tumor formation. Why the cells are more common on the left, Ramsdell has not yet figured out. But we think it has to do with the embryonic environment the cells grow up in, which is quite different on both sides.

Ramsdell and a cadre of other developmental biologists are trying to unravel why the organisms can tell their right from left. Its a complex process, but the key orchestrators of the handedness of life are beginning to come into clearer focus.

A Left Turn

In the 1990s, scientists studying the activity of different genes in the developing embryo discovered something surprising. In every vertebrate embryo examined so far, a gene called Nodal appears on the left side of the embryo. It is closely followed by its collaborator Lefty, a gene that suppresses Nodal activity on the embryos right. The Nodal-Lefty team appears to be the most important genetic pathway that guides asymmetry, said Cliff Tabin, an evolutionary biologist at Harvard University who played a central role in the initial research into Nodal and Lefty.

But what triggers the emergence of Nodal and Lefty inside the embryo? The developmental biologist Nobutaka Hirokawa came up with an explanation that is so elegant we all want to believe it, Tabin said. Most vertebrate embryos start out as a tiny disk. On the bottom side of this disk, theres a little pit, the floor of which is covered in ciliaflickering cell extensions that, Hirokawa suggested, create a leftward current in the surrounding fluid. A 2002 study confirmed that a change in flow direction could change the expression of Nodal as well.

The twospot flounder lies on the seafloor on its right side, with both eyes on its left side.SEFSC Pascagoula Laboratory; Collection of Brandi Noble, NOAA/NMFS/SEFSC

Damaged cilia have long been associated with asymmetry-related disease. In Kartagener syndrome, for example, immobile cilia in the windpipe cause breathing difficulties. Intriguingly, the body asymmetry of people with the syndrome is often entirely inversed, to become an almost perfect mirror image of what it would otherwise. In the early 2000s, researchers discovered that the syndrome was caused by defects in a number of proteins driving movement in cells, including those of the cilia. In addition, a 2015 Nature study identified two dozen mouse genes related to cilia that give rise to unusual asymmetries when defective.

Yet cilia cannot be the whole story. Many animals, even some mammals, dont have a ciliated pit, said Michael Levin, a biologist at Tufts University who was the first author on some of the Nodal papers from Tabins lab in the 1990s.

In addition, the motor proteins critical for normal asymmetry development dont only occur in the cilia, Levin said. They also work with the cellular skeleton, a network of sticks and strands that provides structure to the cell, to guide its movements and transport cellular components.

An increasing number of studies suggest that this may give rise to asymmetry within individual cells as well. Cells have a kind of handedness, said Leo Wan, a biomedical engineer at the Rensselaer Polytechnic Institute. When they hit an obstacle, some types of cells will turn left while others will turn right. Wan has created a test that consists of a plate with two concentric, circular ridges. We place cells between those ridges, then watch them move around, he said. When they hit one of the ridges, they turn, and their preferred direction is clearly visible.

The red crossbill uses its unique beak to access the seeds in conifer cones.Jason Crotty

Wan believes the cells preference depends on the interplay between two elements of the cellular skeleton: actin and myosin. Actin is a protein that forms trails throughout the cell. Myosin, another protein, moves across these trails, often while dragging other cellular components along. Both proteins are well-known for their activity in muscle cells, where they are crucial for contraction. Kenji Matsuno, a cellular biologist at Osaka University, has discovered a series of what he calls unconventional myosins that appear crucial to asymmetrical development. Matsuno agrees that myosins are likely causing cell handedness.

Consider the fruit fly. It lacks both the ciliated pit as well as Nodal, yet it develops an asymmetric hindgut. Matsuno has demonstrated that the handedness of cells in the hindgut depends on myosin and that the handedness reflected by the cells initial tilt is what guides the guts development. The cells handedness does not just define how they move, but also how they hold on to each other, he explains. Together those wrestling cells create a hindgut that curves and turns exactly the way its supposed to. A similar process was described in the roundworm C. elegans.

Nodal isnt necessary for the development of all asymmetry in vertebrates, either. In a study published in Nature Communications in 2013, Jeroen Bakkers, a biologist at the Hubrecht Institute in the Netherlands, described how the zebra fish heart may curve to the right in the absence of Nodal. In fact, he went on to show that it even does so when removed from the body and deposited into a simple lab dish. That being said, he adds, in animals without Nodal, the heart did not shift left as it should, nor did it turn correctly. Though some asymmetry originates within, the cells do need Nodals help.

The European red slug has a large, dark respiratory pore on its right side.Hans Hillewaert

For Tabin, experiments like this show that while Nodal may not be the entire story, it is the most crucial factor in the development of asymmetry. From the standpoint of evolution, it turns out, breaking symmetry wasnt that difficult, he said. There are multiple ways of doing it, and different organisms have done it in different ways. The key that evolution had to solve was making asymmetry reliable and robust, he said. Lefty and Nodal together are a way of making sure that asymmetry is robust.

Yet others believe that important links are waiting to be discovered. Research from Levins lab suggests that communication among cells may be an under-explored factor in the development of asymmetry.

The cellular skeleton also directs the transport of specialized proteins to the cell surface, Levin said. Some of these allow cells to communicate by exchanging electrical charges. This electrical communication, his research suggests, may direct the movements of cells as well as how the cells express their genes. If we block the [communication] channels, asymmetrical development always goes awry, he said. And by manipulating this system, weve been able to guide development in surprising but predictable directions, creating six-legged frogs, four-headed worms or froglets with an eye for a gut, without changing their genomes at all.

The apparent ability of developing organisms to detect and correct their own shape fuels Levins belief that self-repair might one day be an option for humans as well. Under every rock, there is a creature that can repair its complex body all by itself, he points out. If we can figure out how this works, Levin said, it might revolutionize medicine. Many people think Im too optimistic, but I have the engineering view on this: Anything thats not forbidden by the laws of physics is possible.

Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.

Read more: https://www.wired.com/2017/02/body-can-tell-left-right/

How Life (and Death) Spring From Disorder

Whats the difference between physics and biology? Take a golf ball and a cannonball and drop them off the Tower of Pisa. The laws of physics allow you to predict their trajectories pretty much as accurately as you could wish for.

Quanta Magazine


About

Original storyreprinted with permission from Quanta Magazine, an editorially independent division of theSimons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences


Now do the same experiment again, but replace the cannonball with a pigeon.

Biological systems dont defy physical laws, of coursebut neither do they seem to be predicted by them. In contrast, they are goal-directed: survive and reproduce. We can say that they have a purposeor what philosophers have traditionally called a teleologythat guides their behavior.

By the same token, physics now lets us predict, starting from the state of the universe a billionth of a second after the Big Bang, what it looks like today. But no one imagines that the appearance of the first primitive cells on Earth led predictably to the human race. Laws do not, it seems, dictate the course of evolution.

The teleology and historical contingency of biology, said the evolutionary biologist Ernst Mayr, make it unique among the sciences. Both of these features stem from perhaps biologys only general guiding principle: evolution. It depends on chance and randomness, but natural selection gives it the appearance of intention and purpose. Animals are drawn to water not by some magnetic attraction, but because of their instinct, their intention, to survive. Legs serve the purpose of, among other things, taking us to the water.

Mayr claimed that these features make biology exceptionala law unto itself. But recent developments in nonequilibrium physics, complex systems science and information theory are challenging that view.

Once we regard living things as agents performing a computationcollecting and storing information about an unpredictable environmentcapacities and considerations such as replication, adaptation, agency, purpose and meaning can be understood as arising not from evolutionary improvisation, but as inevitable corollaries of physical laws. In other words, there appears to be a kind of physics of things doing stuff, and evolving to do stuff. Meaning and intentionthought to be the defining characteristics of living systemsmay then emerge naturally through the laws of thermodynamics and statistical mechanics.

This past November, physicists, mathematicians and computer scientists came together with evolutionary and molecular biologists to talkand sometimes argueabout these ideas at a workshop at the Santa Fe Institute in New Mexico, the mecca for the science of complex systems. They asked: Just how special (or not) is biology?

Its hardly surprising that there was no consensus. But one message that emerged very clearly was that, if theres a kind of physics behind biological teleology and agency, it has something to do with the same concept that seems to have become installed at the heart of fundamental physics itself: information.

Disorder and Demons

The first attempt to bring information and intention into the laws of thermodynamics came in the middle of the 19th century, when statistical mechanics was being invented by the Scottish scientist James Clerk Maxwell. Maxwell showed how introducing these two ingredients seemed to make it possible to do things that thermodynamics proclaimed impossible.

Maxwell had already shown how the predictable and reliable mathematical relationships between the properties of a gaspressure, volume and temperaturecould be derived from the random and unknowable motions of countless molecules jiggling frantically with thermal energy. In other words, thermodynamicsthe new science of heat flow, which united large-scale properties of matter like pressure and temperaturewas the outcome of statistical mechanics on the microscopic scale of molecules and atoms.

According to thermodynamics, the capacity to extract useful work from the energy resources of the universe is always diminishing. Pockets of energy are declining, concentrations of heat are being smoothed away. In every physical process, some energy is inevitably dissipated as useless heat, lost among the random motions of molecules. This randomness is equated with the thermodynamic quantity called entropya measurement of disorderwhich is always increasing. That is the second law of thermodynamics. Eventually all the universe will be reduced to a uniform, boring jumble: a state of equilibrium, wherein entropy is maximized and nothing meaningful will ever happen again.

Are we really doomed to that dreary fate? Maxwell was reluctant to believe it, and in 1867 he set out to, as he put it, pick a hole in the second law. His aim was to start with a disordered box of randomly jiggling molecules, then separate the fast molecules from the slow ones, reducing entropy in the process.

Imagine some little creaturethe physicist William Thomson later called it, rather to Maxwells dismay, a demonthat can see each individual molecule in the box. The demon separates the box into two compartments, with a sliding door in the wall between them. Every time he sees a particularly energetic molecule approaching the door from the right-hand compartment, he opens it to let it through. And every time a slow, cold molecule approaches from the left, he lets that through, too. Eventually, he has a compartment of cold gas on the right and hot gas on the left: a heat reservoir that can be tapped to do work.

This is only possible for two reasons. First, the demon has more information than we do: It can see all of the molecules individually, rather than just statistical averages. And second, it has intention: a plan to separate the hot from the cold. By exploiting its knowledge with intent, it can defy the laws of thermodynamics.

At least, so it seemed. It took a hundred years to understand why Maxwells demon cant in fact defeat the second law and avert the inexorable slide toward deathly, universal equilibrium. And the reason shows that there is a deep connection between thermodynamics and the processing of informationor in other words, computation. The German-American physicist Rolf Landauer showed that even if the demon can gather information and move the (frictionless) door at no energy cost, a penalty must eventually be paid. Because it cant have unlimited memory of every molecular motion, it must occasionally wipe its memory cleanforget what it has seen and start againbefore it can continue harvesting energy. This act of information erasure has an unavoidable price: It dissipates energy, and therefore increases entropy. All the gains against the second law made by the demons nifty handiwork are canceled by Landauers limit: the finite cost of information erasure (or more generally, of converting information from one form to another).

Living organisms seem rather like Maxwells demon. Whereas a beaker full of reacting chemicals will eventually expend its energy and fall into boring stasis and equilibrium, living systems have collectively been avoiding the lifeless equilibrium state since the origin of life about three and a half billion years ago. They harvest energy from their surroundings to sustain this nonequilibrium state, and they do it with intention. Even simple bacteria move with purpose toward sources of heat and nutrition. In his 1944 book What is Life?, the physicist Erwin Schrdinger expressed this by saying that living organisms feed on negative entropy.

They achieve it, Schrdinger said, by capturing and storing information. Some of that information is encoded in their genes and passed on from one generation to the next: a set of instructions for reaping negative entropy. Schrdinger didnt know where the information is kept or how it is encoded, but his intuition that it is written into what he called an aperiodic crystal inspired Francis Crick, himself trained as a physicist, and James Watson when in 1953 they figured out how genetic information can be encoded in the molecular structure of the DNA molecule.

A genome, then, is at least in part a record of the useful knowledge that has enabled an organisms ancestorsright back to the distant pastto survive on our planet. According to David Wolpert, a mathematician and physicist at the Santa Fe Institute who convened the recent workshop, and his colleague Artemy Kolchinsky, the key point is that well-adapted organisms are correlated with that environment. If a bacterium swims dependably toward the left or the right when there is a food source in that direction, it is better adapted, and will flourish more, than one that swims in random directions and so only finds the food by chance. A correlation between the state of the organism and that of its environment implies that they share information in common. Wolpert and Kolchinsky say that its this information that helps the organism stay out of equilibriumbecause, like Maxwells demon, it can then tailor its behavior to extract work from fluctuations in its surroundings. If it did not acquire this information, the organism would gradually revert to equilibrium: It would die.

Looked at this way, life can be considered as a computation that aims to optimize the storage and use of meaningful information. And life turns out to be extremely good at it. Landauers resolution of the conundrum of Maxwells demon set an absolute lower limit on the amount of energy a finite-memory computation requires: namely, the energetic cost of forgetting. The best computers today are far, far more wasteful of energy than that, typically consuming and dissipating more than a million times more. But according to Wolpert, a very conservative estimate of the thermodynamic efficiency of the total computation done by a cell is that it is only 10 or so times more than the Landauer limit.

The implication, he said, is that natural selection has been hugely concerned with minimizing the thermodynamic cost of computation. It will do all it can to reduce the total amount of computation a cell must perform. In other words, biology (possibly excepting ourselves) seems to take great care not to overthink the problem of survival. This issue of the costs and benefits of computing ones way through life, he said, has been largely overlooked in biology so far.

Inanimate Darwinism

So living organisms can be regarded as entities that attune to their environment by using information to harvest energy and evade equilibrium. Sure, its a bit of a mouthful. But notice that it said nothing about genes and evolution, on which Mayr, like many biologists, assumed that biological intention and purpose depend.

How far can this picture then take us? Genes honed by natural selection are undoubtedly central to biology. But could it be that evolution by natural selection is itself just a particular case of a more general imperative toward function and apparent purpose that exists in the purely physical universe? It is starting to look that way.

Adaptation has long been seen as the hallmark of Darwinian evolution. But Jeremy England at the Massachusetts Institute of Technology has argued that adaptation to the environment can happen even in complex nonliving systems.

Adaptation here has a more specific meaning than the usual Darwinian picture of an organism well-equipped for survival. One difficulty with the Darwinian view is that theres no way of defining a well-adapted organism except in retrospect. The fittest are those that turned out to be better at survival and replication, but you cant predict what fitness entails. Whales and plankton are well-adapted to marine life, but in ways that bear little obvious relation to one another.

Englands definition of adaptation is closer to Schrdingers, and indeed to Maxwells: A well-adapted entity can absorb energy efficiently from an unpredictable, fluctuating environment. It is like the person who keeps his footing on a pitching ship while others fall over because shes better at adjusting to the fluctuations of the deck. Using the concepts and methods of statistical mechanics in a nonequilibrium setting, England and his colleagues argue that these well-adapted systems are the ones that absorb and dissipate the energy of the environment, generating entropy in the process.

Complex systems tend to settle into these well-adapted states with surprising ease, said England: Thermally fluctuating matter often gets spontaneously beaten into shapes that are good at absorbing work from the time-varying environment.

There is nothing in this process that involves the gradual accommodation to the surroundings through the Darwinian mechanisms of replication, mutation and inheritance of traits. Theres no replication at all. What is exciting about this is that it means that when we give a physical account of the origins of some of the adapted-looking structures we see, they dont necessarily have to have had parents in the usual biological sense, said England. You can explain evolutionary adaptation using thermodynamics, even in intriguing cases where there are no self-replicators and Darwinian logic breaks downso long as the system in question is complex, versatile and sensitive enough to respond to fluctuations in its environment.

But neither is there any conflict between physical and Darwinian adaptation. In fact, the latter can be seen as a particular case of the former. If replication is present, then natural selection becomes the route by which systems acquire the ability to absorb workSchrdingers negative entropyfrom the environment. Self-replication is, in fact, an especially good mechanism for stabilizing complex systems, and so its no surprise that this is what biology uses. But in the nonliving world where replication doesnt usually happen, the well-adapted dissipative structures tend to be ones that are highly organized, like sand ripples and dunes crystallizing from the random dance of windblown sand. Looked at this way, Darwinian evolution can be regarded as a specific instance of a more general physical principle governing nonequilibrium systems.

Prediction Machines

This picture of complex structures adapting to a fluctuating environment allows us also to deduce something about how these structures store information. In short, so long as such structureswhether living or notare compelled to use the available energy efficiently, they are likely to become prediction machines.

Its almost a defining characteristic of life that biological systems change their state in response to some driving signal from the environment. Something happens; you respond. Plants grow toward the light; they produce toxins in response to pathogens. These environmental signals are typically unpredictable, but living systems learn from experience, storing up information about their environment and using it to guide future behavior. (Genes, in this picture, just give you the basic, general-purpose essentials.)

Prediction isnt optional, though. According to the work of Susanne Still at the University of Hawaii, Gavin Crooks, formerly at the Lawrence Berkeley National Laboratory in California, and their colleagues, predicting the future seems to be essential for any energy-efficient system in a random, fluctuating environment.

Theres a thermodynamic cost to storing information about the past that has no predictive value for the future, Still and colleagues show. To be maximally efficient, a system has to be selective. If it indiscriminately remembers everything that happened, it incurs a large energy cost. On the other hand, if it doesnt bother storing any information about its environment at all, it will be constantly struggling to cope with the unexpected. A thermodynamically optimal machine must balance memory against prediction by minimizing its nostalgiathe useless information about the past, said a co-author, David Sivak, now at Simon Fraser University in Burnaby, British Columbia. In short, it must become good at harvesting meaningful informationthat which is likely to be useful for future survival.

Youd expect natural selection to favor organisms that use energy efficiently. But even individual biomolecular devices like the pumps and motors in our cells should, in some important way, learn from the past to anticipate the future. To acquire their remarkable efficiency, Still said, these devices must implicitly construct concise representations of the world they have encountered so far, enabling them to anticipate whats to come.

The Thermodynamics of Death

Even if some of these basic information-processing features of living systems are already prompted, in the absence of evolution or replication, by nonequilibrium thermodynamics, you might imagine that more complex traitstool use, say, or social cooperationmust be supplied by evolution.

Well, dont count on it. These behaviors, commonly thought to be the exclusive domain of the highly advanced evolutionary niche that includes primates and birds, can be mimicked in a simple model consisting of a system of interacting particles. The trick is that the system is guided by a constraint: It acts in a way that maximizes the amount of entropy (in this case, defined in terms of the different possible paths the particles could take) it generates within a given timespan.

Entropy maximization has long been thought to be a trait of nonequilibrium systems. But the system in this model obeys a rule that lets it maximize entropy over a fixed time window that stretches into the future. In other words, it has foresight. In effect, the model looks at all the paths the particles could take and compels them to adopt the path that produces the greatest entropy. Crudely speaking, this tends to be the path that keeps open the largest number of options for how the particles might move subsequently.

You might say that the system of particles experiences a kind of urge to preserve freedom of future action, and that this urge guides its behavior at any moment. The researchers who developed the modelAlexander Wissner-Gross at Harvard University and Cameron Freer, a mathematician at the Massachusetts Institute of Technologycall this a causal entropic force. In computer simulations of configurations of disk-shaped particles moving around in particular settings, this force creates outcomes that are eerily suggestive of intelligence.

In one case, a large disk was able to use a small disk to extract a second small disk from a narrow tubea process that looked like tool use. Freeing the disk increased the entropy of the system. In another example, two disks in separate compartments synchronized their behavior to pull a larger disk down so that they could interact with it, giving the appearance of social cooperation.

Of course, these simple interacting agents get the benefit of a glimpse into the future. Life, as a general rule, does not. So how relevant is this for biology? Thats not clear, although Wissner-Gross said that he is now working to establish a practical, biologically plausible, mechanism for causal entropic forces. In the meantime, he thinks that the approach could have practical spinoffs, offering a shortcut to artificial intelligence. I predict that a faster way to achieve it will be to discover such behavior first and then work backward from the physical principles and constraints, rather than working forward from particular calculation or prediction techniques, he said. In other words, first find a system that does what you want it to do and then figure out how it does it.

Aging, too, has conventionally been seen as a trait dictated by evolution. Organisms have a lifespan that creates opportunities to reproduce, the story goes, without inhibiting the survival prospects of offspring by the parents sticking around too long and competing for resources. That seems surely to be part of the story, but Hildegard Meyer-Ortmanns, a physicist at Jacobs University in Bremen, Germany, thinks that ultimately aging is a physical process, not a biological one, governed by the thermodynamics of information.

Its certainly not simply a matter of things wearing out. Most of the soft material we are made of is renewed before it has the chance to age, Meyer-Ortmanns said. But this renewal process isnt perfect. The thermodynamics of information copying dictates that there must be a trade-off between precision and energy. An organism has a finite supply of energy, so errors necessarily accumulate over time. The organism then has to spend an increasingly large amount of energy to repair these errors. The renewal process eventually yields copies too flawed to function properly; death follows.

Empirical evidence seems to bear that out. It has been long known that cultured human cells seem able to replicate no more than 40 to 60 times (called the Hayflick limit) before they stop and become senescent. And recent observations of human longevity have suggested that there may be some fundamental reason why humans cant survive much beyond age 100.

Theres a corollary to this apparent urge for energy-efficient, organized, predictive systems to appear in a fluctuating nonequilibrium environment. We ourselves are such a system, as are all our ancestors back to the first primitive cell. And nonequilibrium thermodynamics seems to be telling us that this is just what matter does under such circumstances. In other words, the appearance of life on a planet like the early Earth, imbued with energy sources such as sunlight and volcanic activity that keep things churning out of equilibrium, starts to seem not an extremely unlikely event, as many scientists have assumed, but virtually inevitable. In 2006, Eric Smith and the late Harold Morowitz at the Santa Fe Institute argued that the thermodynamics of nonequilibrium systems makes the emergence of organized, complex systems much more likely on a prebiotic Earth far from equilibrium than it would be if the raw chemical ingredients were just sitting in a warm little pond (as Charles Darwin put it) stewing gently.

In the decade since that argument was first made, researchers have added detail and insight to the analysis. Those qualities that Ernst Mayr thought essential to biologymeaning and intentionmay emerge as a natural consequence of statistics and thermodynamics. And those general properties may in turn lead naturally to something like life.

At the same time, astronomers have shown us just how many worlds there areby some estimates stretching into the billionsorbiting other stars in our galaxy. Many are far from equilibrium, and at least a few are Earth-like. And the same rules are surely playing out there, too.

Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.

Read more: https://www.wired.com/2017/02/life-death-spring-disorder/

How Did Life Begin? Dividing Droplets Could Hold the Answer

A collaboration of physicists and biologists in Germany has found a simple mechanism that might have enabled liquid droplets to evolve into living cells in early Earths primordial soup.

Origin-of-life researchers have praised the minimalism of the idea. Ramin Golestanian, a professor of theoretical physics at the University of Oxford who was not involved in the research, called it a big achievement that suggests that the general phenomenology of life formation is a lot easier than one might think.

Quanta Magazine


About

Original storyreprinted with permission from Quanta Magazine, an editorially independent division of theSimons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences


The central question about the origin of life has been how the first cells arose from primitive precursors. What were those precursors, dubbed protocells, and how did they come alive? Proponents of the membrane-first hypothesis have argued that a fatty-acid membrane was needed to corral the chemicals of life and incubate biological complexity. But how could something as complex as a membrane start to self-replicate and proliferate, allowing evolution to act on it?

In 1924, Alexander Oparin, the Russian biochemist who first envisioned a hot, briny primordial soup as the source of lifes humble beginnings, proposed that the mystery protocells might have been liquid dropletsnaturally forming, membrane-free containers that concentrate chemicals and thereby foster reactions. In recent years, droplets have been found to perform a range of essential functions inside modern cells, reviving Oparins long-forgotten speculation about their role in evolutionary history. But neither he nor anyone else could explain how droplets might have proliferated, growing and dividing and, in the process, evolving into the first cells.

Now, the new work by David Zwicker and collaborators at the Max Planck Institute for the Physics of Complex Systems and the Max Planck Institute of Molecular Cell Biology and Genetics, both in Dresden, suggests an answer. The scientists studied the physics of chemically active droplets, which cycle chemicals in and out of the surrounding fluid, and discovered that these droplets tend to grow to cell size and divide, just like cells. This active droplet behavior differs from the passive and more familiar tendencies of oil droplets in water, which glom together into bigger and bigger droplets without ever dividing.

If chemically active droplets can grow to a set size and divide of their own accord, then it makes it more plausible that there could have been spontaneous emergence of life from nonliving soup, said Frank Jlicher, a biophysicist in Dresden and a co-author of the new paper.

The findings, reported in Nature Physics last month, paint a possible picture of lifes start by explaining how cells made daughters, said Zwicker, who is now a postdoctoral researcher at Harvard University. This is, of course, key if you want to think about evolution.

Luca Giomi, a theoretical biophysicist at Leiden University in the Netherlands who studies the possible physical mechanisms behind the origin of life, said the new proposal is significantly simpler than other mechanisms of protocell division that have been considered, calling it a very promising direction.

However, David Deamer, a biochemist at the University of California, Santa Cruz, and a longtime champion of the membrane-first hypothesis, argues that while the newfound mechanism of droplet division is interesting, its relevance to the origin of life remains to be seen. The mechanism is a far cry, he noted, from the complicated, multistep process by which modern cells divide.

Could simple dividing droplets have evolved into the teeming menagerie of modern life, from amoebas to zebras? Physicists and biologists familiar with the new work say its plausible. As a next step, experiments are under way in Dresden to try to observe the growth and division of active droplets made of synthetic polymers that are modeled after the droplets found in living cells. After that, the scientists hope to observe biological droplets dividing in the same way.

Clifford Brangwynne, a biophysicist at Princeton University who was part of the Dresden-based team that identified the first subcellular droplets eight years agotiny liquid aggregates of protein and RNA in cells of the worm C. elegansexplained that it would not be surprising if these were vestiges of evolutionary history. Just as mitochondria, organelles that have their own DNA, came from ancient bacteria that infected cells and developed a symbiotic relationship with them, the condensed liquid phases that we see in living cells might reflect, in a similar sense, a sort of fossil record of the physicochemical driving forces that helped set up cells in the first place, he said.

This Nature Physics paper takes that to the next level, by revealing the features that droplets would have needed to play a role as protocells, Brangwynne added.

Droplets in Dresden

The Dresden droplet discoveries began in 2009, when Brangwynne and collaborators demystified the nature of little dots known as P granules in C. elegans germline cells, which undergo division into sperm and egg cells. During this division process, the researchers observed that P granules grow, shrink and move across the cells via diffusion. The discovery that they are liquid droplets, reported in Science, prompted a wave of activity as other subcellular structures were also identified as droplets. It didnt take long for Brangwynne and Tony Hyman, head of the Dresden biology lab where the initial experiments took place, to make the connection to Oparins 1924 protocell theory. In a 2012 essay about Oparins life and seminal book, The Origin of Life, Brangwynne and Hyman wrote that the droplets he theorized about may still be alive and well, safe within our cells, like flies in lifes evolving amber.

Oparin most famously hypothesized that lightning strikes or geothermal activity on early Earth could have triggered the synthesis of organic macromolecules necessary for lifea conjecture later made independently by the British scientist John Haldane and triumphantly confirmed by the Miller-Urey experiment in the 1950s. Another of Oparins ideas, that liquid aggregates of these macromolecules might have served as protocells, was less celebrated, in part because he had no clue as to how the droplets might have reproduced, thereby enabling evolution. The Dresden group studying P granules didnt know either.

In the wake of their discovery, Jlicher assigned his new student, Zwicker, the task of unraveling the physics of centrosomes, organelles involved in animal cell division that also seemed to behave like droplets. Zwicker modeled the centrosomes as out-of-equilibrium systems that are chemically active, continuously cycling constituent proteins into and out of the surrounding liquid cytoplasm. In his model, these proteins have two chemical states. Proteins in state A dissolve in the surrounding liquid, while those in state B are insoluble, aggregating inside a droplet. Sometimes, proteins in state B spontaneously switch to state A and flow out of the droplet. An energy source can trigger the reverse reaction, causing a protein in state A to overcome a chemical barrier and transform into state B; when this insoluble protein bumps into a droplet, it slinks easily inside, like a raindrop in a puddle. Thus, as long as theres an energy source, molecules flow in and out of an active droplet. In the context of early Earth, sunlight would be the driving force, Jlicher said.

Zwicker discovered that this chemical influx and efflux will exactly counterbalance each other when an active droplet reaches a certain volume, causing the droplet to stop growing. Typical droplets in Zwickers simulations grew to tens or hundreds of microns across depending on their propertiesthe scale of cells.

Lucy Reading-Ikkanda/Quanta Magazine

The next discovery was even more unexpected. Although active droplets have a stable size, Zwicker found that they are unstable with respect to shape: When a surplus of B molecules enters a droplet on one part of its surface, causing it to bulge slightly in that direction, the extra surface area from the bulging further accelerates the droplets growth as more molecules can diffuse inside. The droplet elongates further and pinches in at the middle, which has low surface area. Eventually, it splits into a pair of droplets, which then grow to the characteristic size. When Jlicher saw simulations of Zwickers equations, he immediately jumped on it and said, That looks very much like division, Zwicker said. And then this whole protocell idea emerged quickly.

Zwicker, Jlicher and their collaborators, Rabea Seyboldt, Christoph Weber and Tony Hyman, developed their theory over the next three years, extending Oparins vision. If you just think about droplets like Oparin did, then its not clear how evolution could act on these droplets, Zwicker said. For evolution, you have to make copies of yourself with slight modifications, and then natural selection decides how things get more complex.

Globule Ancestor

Last spring, Jlicher began meeting with Dora Tang, head of a biology lab at the Max Planck Institute of Molecular Cell Biology and Genetics, to discuss plans to try to observe active-droplet division in action.

Tangs lab synthesizes artificial cells made of polymers, lipids and proteins that resemble biochemical molecules. Over the next few months, she and her team will look for division of liquid droplets made of polymers that are physically similar to the proteins in P granules and centrosomes. The next step, which will be made in collaboration with Hymans lab, is to try to observe centrosomes or other biological droplets dividing, and to determine if they utilize the mechanism identified in the paper by Zwicker and colleagues. That would be a big deal, said Giomi, the Leiden biophysicist.

When Deamer, the membrane-first proponent, read the new paper, he recalled having once observed something like the predicted behavior in hydrocarbon droplets he had extracted from a meteorite. When he illuminated the droplets in near-ultraviolet light, they began moving and dividing. (He sent footage of the phenomenon to Jlicher.) Nonetheless, Deamer isnt convinced of the effects significance. There is no obvious way for the mechanism of division they reported to evolve into the complex process by which living cells actually divide, he said.

Other researchers disagree, including Tang. She says that once droplets started to divide, they could easily have gained the ability to transfer genetic information, essentially divvying up a batch of protein-coding RNA or DNA into equal parcels for their daughter cells. If this genetic material coded for useful proteins that increased the rate of droplet division, natural selection would favor the behavior. Protocells, fueled by sunlight and the law of increasing entropy, would gradually have grown more complex.

Jlicher and colleagues argue that somewhere along the way, protocell droplets could have acquired membranes. Droplets naturally collect crusts of lipids that prefer to lie at the interface between the droplets and the surrounding liquid. Somehow, genes might have started coding for these membranes as a kind of protection. When this idea was put to Deamer, he said, I can go along with that, noting that he would define protocells as the first droplets that had membranes.

The primordial plotline hinges, of course, on the outcome of future experiments, which will determine how robust and relevant the predicted droplet division mechanism really is. Can chemicals be found with the right two states, A and B, to bear out the theory? If so, then a viable path from nonlife to life starts to come into focus.

The luckiest part of the whole process, in Jlichers opinion, was not that droplets turned into cells, but that the first dropletour globule ancestorformed to begin with. Droplets require a lot of chemical material to spontaneously arise or nucleate, and its unclear how so many of the right complex macromolecules could have accumulated in the primordial soup to make it happen. But then again, Jlicher said, there was a lot of soup, and it was stewing for eons.

Its a very rare event. You have to wait a long time for it to happen, he said. And once it happens, then the next things happen more easily, and more systematically.

Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.

Read more: https://www.wired.com/2017/01/life-begin-dividing-droplets-hold-answer/