Thursday, 21 March 2019

Japan will allow gene-edited foodstuffs to be sold to consumers

Dennis Normile

Japan will allow gene-edited foodstuffs to be sold to consumers without safety evaluations as long as the techniques involved meet certain criteria, if recommendations agreed on by an advisory panel yesterday are adopted by the Ministry of Health, Labour and Welfare. This would open the door to using CRISPR and other techniques on plants and animals intended for human consumption in the country.

“There is little difference between traditional breeding methods and gene editing in terms of safety,” Hirohito Sone, an endocrinologist at Niigata University who chaired the expert panel, told NHK, Japan’s national public broadcaster.

How to regulate gene-edited food is a hotly debated issue internationally. Scientists and regulators have recognized a difference between genetic modification, which typically involves transferring a gene from one organism to another, and gene editing, in which certain genes within an organism are disabled or altered using new techniques such as CRISPR. That’s why a year ago, the U.S. Food and Drug Administration concluded that most gene-edited foods would not need regulation. But the European Union’s Court of Justice ruled in July 2018 that gene-edited crops must go through the same lengthy approval process as traditional transgenic plants.

Now, Japan appears set to follow the U.S. example. The final report, approved yesterday, was not immediately available, but an earlier draft was posted on the ministry website. The report says no safety screening should be required provided the techniques used do not leave foreign genes or parts of genes in the target organism. In light of that objective, the panel concluded it would be reasonable to require information on the editing technique, the genes targeted for modification, and other details from developers or users that would be made public while respecting proprietary information.

The recommendations leave open the possibility of requiring safety evaluations if there are insufficient details on the editing technique. The draft report does not directly tackle the issue of whether such foods should be labeled. The ministry is expected to largely follow the recommendations in finalizing a policy on gene-edited foods later this year.

Consumer groups had voiced opposition to the draft recommendations, which were released for public comment in December 2018. Using the slogan “No need for genetically modified food!” the Consumers Union of Japan joined other groups circulating a petition calling for regulating the cultivation of all gene-edited crops, and safety reviews and labeling of all gene-edited foods.

Whether consumers will embrace the new technology remains to be seen. Japan has approved the sale of genetically modified (GM) foods that have passed safety tests as long as they are labeled. But public wariness has limited consumption and has led most Japanese farmers to shun GM crops. The country does import sizable volumes of GM processed food and livestock feed, however. Japanese researchers are reportedly working on gene-edited potatoes, tomatoes, rice, chicken, and fish. “Thorough explanations [of the new technologies] are needed to ease public concerns,” Sone said.

Wednesday, 13 March 2019

Using arts education to help other lessons stick

Perri Klass
In “A Tree Grows in Brooklyn,” Betty Smith’s 1943 autobiographical novel about growing up poor in the early 20th century, the public school that the heroine attends is a pretty bleak place. But “there was a great golden glory lasting a half-hour each week when Mr. Morton came to Francie’s room to teach music.”

He taught them classical music, the book continues, without telling them what they were learning, setting his own words to the great works. “Little boys whistled part of Dvorak’s New World Symphony as they played marbles. When asked the name of the song, they’d reply ‘Oh, “Going Home.”’ They played potsy, humming ‘The Soldiers’ Chorus’ from Faust, which they called ‘Glory.’”

Francie also looked forward to the visits of the drawing teacher; “these two visiting teachers were the gold and silver sun-splash in the great muddy river of school days.”

Arts education in schools has introduced many children to great painters and great music, and helped them through their first dance steps or tentative musical endeavors. It can serve as a bright spot in the schoolchild’s day or week, a class that brings in beauty, color and joy, and which is not about testing.

These subjects are often under threat either from budget cuts or from the inexorable demands of academic testing and “accountability,” but insights from neuroscience suggest that arts education can play additional important roles in how children learn.

Paul T. Sowden, a professor of psychology at the University of Winchester in England, warned that in Britain, as in the United States, arts and humanities subjects have suffered in recent years as the emphasis shifted to science and technology. It's important, he said, that arts education be available equally to everyone. But arts education, he said, is a chance to build resilience and determination in children, as well as to help them master complex skills.

Arts education encompasses many disciplines: “I’m talking about everything from music, drama, dance, design, visual arts,” Dr. Sowden said. And the goal goes beyond the specific subjects, he said: “You’re looking for opportunities in the arts education context to encourage children to ask questions, to use their imaginations, but also to approach their work in a systematic, disciplined way.”

When children are younger, arts education helps develop their capacity for collaboration, for creativity, and even for asking questions. As they get older, he said, “their executive function is much more developed, their ability to sustain attentional tasks is much greater.” For them, arts education can offer the chance to refine and polish a skill over time, or revise a project until it is as good as it can be.

Sometimes the arts are taught in a very set curriculum, Dr. Sowden said, but there are real advantages to teaching in a more exploratory way, where children can experiment. And both parents and teachers can encourage children to explore, he said; “that’s the way you get the biggest benefit, not just learning to reproduce a particular work by Monet or dance sequence.”

The skills that children master in arts education, he said, may be transferable to other curricular areas.
Mariale Hardiman, a professor at the Johns Hopkins School of Education, where she directs the neuro-education initiative, was interested in how children do — and don’t — retain what they learn in school. “A lot of the information we teach doesn’t stick.”

What she saw as a school principal, she said, was that when arts were integrated into the curriculum, “learning became more visible.” Teachers told her “the children would remember the information better when they taught it through the arts.”

So though arts education has many other benefits, she said, such as creative thinking, her studies have focused on children’s memory for academic subjects, comparing what children remembered 10 weeks after material was taught. Researchers wrote two different versions of the curriculum, matched for content and timing, both involving active learning, but one including arts education. For example, in an arts integrated curriculum, students would sketch their vocabulary words, or learn some of the material as songs, or act out molecular motion with their bodies.

The children who had learned the material in the curriculum that made use of the arts remembered more, and the effect was largest among the children who were less strong academically, the “lower performers.”

“We found the biggest difference with children at the lower level of achievement,” Dr. Hardiman said. “Could this be at least one lever for closing an achievement gap?” After all, these are often the students who are condemned to dreary drill and repetition, in hopes of bringing them to a higher level: “What if the arts are a lever of school reform, better than the drill and kill we do with remedial students?”

In a 2019 article in the journal Trends in Neuroscience and Education, Dr. Hardiman and her colleagues described the results of a randomized controlled trial looking at fifth-graders who were taught science content, some using techniques from arts education, and others with more conventional instruction. The researchers again saw an effect on the students with more limited reading skills; they remembered more science if they had learned with the integrated arts methods.

So why might the arts integration help children’s memory? “Arts allow for elaboration, allow for repetition,” Dr. Hardiman said. “Memory is certainly enhanced through repetition, the more you revisit something, the more you remember it.” And the visual and performing arts also allow children to elaborate in creative ways on the material.

The advantage of learning through the arts will come as no surprise to anyone who grew up with the “Fifty Nifty United States” song or learned how a bill becomes a law from Schoolhouse Rock. Some of today’s children are learning history from the lyrics of “Hamilton.”

I suddenly remembered a rather mournful tune from decades ago, in high school, when a science teacher told us we would be tested on the elements with a charge of positive 2 and a friend and I set them to a chant; I can still name them, in order, and when it comes to chemistry, I am definitely one of the less able students.

“Arts integration should not replace arts education,” Dr. Hardiman said. She suggested a “three-legged stool,” with one leg being arts education, including dedicated classes in visual and performing arts, and the second arts and cultural offerings, such as artists coming into the school or visits to museums. The third leg would be the integration of the arts into the teaching of other subjects.

“Parents can easily do simple arts activities with kids,” Dr. Hardiman said, and can incorporate these ideas around homework or just in spending time together. Maybe it would help to put the multiplication tables into a song, or ask children to sketch their ideas, or use body poses to show the emotion that a character in a story is feeling.

Ronald Beghetto, a professor of educational psychology and the director of Innovation House at the University of Connecticut, studies creativity in educational settings, which, he said, “can be manifest across all different disciplines.”

“We tend, as adults, to overplan and overstructure young people’s experiences,” Dr. Beghetto said. While structure is important, he said, so is “letting kids determine their own problems to solve, their own ways to solve them.”

Arts education, he said, can provide those structured opportunities that foster creativity.
“Working through some creative endeavor, we’re really resolving uncertainty,” he said. “We approach the blank canvas.”

Friday, 1 March 2019

The dominance of the West represents a historical blip in the last millennium

Alan Mikhail, the author of three books, is a professor of history at Yale
 Where to end the story? For historians, the answer to this question can often shape their accounting of the past. “Empires of the Weak” very consciously ends its story right now.

Most histories written in or about the 20th century accept some version of the idea that Europe “won” world history. From the perspective of today, however, this seems an increasingly difficult claim to defend. For J. C. Sharman, a professor of international relations at Cambridge, “Europeans didn’t win in the end: Their empires fell, and their military capacity shriveled. Even the United States has experienced more defeats than victories against non-Western forces over the last half-century.”

In Sharman’s account, the dominance of the West (note Europe’s easy baton-pass to the United States), roughly from the Enlightenment to World War II, represents a historical blip in the last millennium. And, perhaps more important, today we seem to be on the cusp of a return to a more regular state of affairs, where the large states of Asia will again be the globe’s hegemons.

To make this provocative argument, Sharman finds the early modern period, conventionally dated from 1500 to 1800, the most fruitful for thinking about where we are headed. In those centuries, the enormous empires of the East — the Qing, the Ottomans and the Mughals — were the most formidable states on earth. Territory equaled power, and those states held the most land.

 Much of this book turns on Sharman’s critique of what historians term the “military revolution thesis” — the idea that advanced military technologies led to Europe’s domination of the world beginning around 1500. Sharman shows this not to be true. For example, he dismantles the notion that the period of Western overseas expansion led to the rise of Europe, either militarily or politically. Asia’s enormous land-based empires didn’t much care about their coastlines and tolerated — more than they succumbed to — the Europeans nibbling on their shores in what were desperate, highly risky and ultimately temporary ventures. Until approximately 1750, Europeans — even in Europe, thanks to the Ottomans — held no military advantage over other powers.

But how then to explain the undeniable fact that Europeans dominated the globe from the turn of the 19th century to World War I? Sharman reasons that it was a combination of internal fractures within the Qing and Ottoman Empires, as well as the inclination of Europeans to think that empire building was the route to national sovereignty: in other words, almost a kind of vanity project. He might have said more about how exactly Europe achieved temporary global pre-eminence, especially as it would bolster his argument that this was a deviation from the norm of the last millennium.

Still, as a critique of prevailing modes of thinking about global politics, “Empires of the Weak” succeeds admirably. The history of international relations has focused too much on the most unrepresentative period of the last millennium — the century and a half in which Europe dominated the world. This weighting of the scales has skewed our understanding of global politics and the importance of the West. Sharman’s is a far richer story and one that perhaps more accurately reflects today’s global rebalancing.

To guess what’s on the other side of the impenetrable wall of the present — always risky — we might venture that global affairs in the year 2100 will look more like it did in 1700 than 1900 and that the center of world power will be in the East rather than the West. As we contemplate the future, we would do well, therefore, to cast our gaze to the early modern period — and to Asia.

Tuesday, 26 February 2019

Have dark forces been messing with the cosmos?

Dennis Overbye

There was, you might say, a disturbance in the Force.

Long, long ago, when the universe was only about 100,000 years old — a buzzing, expanding mass of particles and radiation — a strange new energy field switched on. That energy suffused space with a kind of cosmic antigravity, delivering a not-so-gentle boost to the expansion of the universe.
Then, after another 100,000 years or so, the new field simply winked off, leaving no trace other than a speeded-up universe.

So goes the strange-sounding story being promulgated by a handful of astronomers from Johns Hopkins University. In a bold and speculative leap into the past, the team has posited the existence of this field to explain an astronomical puzzle: the universe seems to be expanding faster than it should be.

The cosmos is expanding only about 9 percent more quickly than theory prescribes. But this slight-sounding discrepancy has intrigued astronomers, who think it might be revealing something new about the universe.

And so, for the last couple of years, they have been gathering in workshops and conferences to search for a mistake or loophole in their previous measurements and calculations, so far to no avail.

“If we’re going to be serious about cosmology, this is the kind of thing we have to be able to take seriously,” said Lisa Randall, a Harvard theorist who has been pondering the problem.

At a recent meeting in Chicago, Josh Frieman, a theorist at the Fermi National Accelerator Laboratory in Batavia, Ill., asked: “At what point do we claim the discovery of new physics?”

Now ideas are popping up. Some researchers say the problem could be solved by inferring the existence of previously unknown subatomic particles. Others, such as the Johns Hopkins group, are invoking new kinds of energy fields.

Adding to the confusion, there already is a force field — called dark energy — making the universe expand faster. And a new, controversial report suggests that this dark energy might be getting stronger and denser, leading to a future in which atoms are ripped apart and time ends.

Thus far, there is no evidence for most of these ideas. If any turn out to be right, scientists may have to rewrite the story of the origin, history and, perhaps, fate of the universe.

Or it could all be a mistake. Astronomers have rigorous methods to estimate the effects of statistical noise and other random errors on their results; not so for the unexamined biases called systematic errors.
As Wendy L. Freedman, of the University of Chicago, said at the Chicago meeting, “The unknown systematic is what gets you in the end.” 

Hubble trouble
Generations of great astronomers have come to grief trying to measure the universe. At issue is a number called the Hubble constant, named after Edwin Hubble, the Mount Wilson astronomer who in 1929 discovered that the universe is expanding.

As space expands, it carries galaxies away from each other like the raisins in a rising cake. The farther apart two galaxies are, the faster they will fly away from each other. The Hubble constant simply says by how much.

But to calibrate the Hubble constant, astronomers depend on so-called standard candles: objects, such as supernova explosions and certain variable stars, whose distances can be estimated by luminosity or some other feature. This is where the arguing begins.

Until a few decades ago, astronomers could not agree on the value of the Hubble constant within a factor of two: either 50 or 100 kilometers per second per megaparsec. (A megaparsec is 3.26 million light years.)

But in 2001, a team using the Hubble Space Telescope, and led by Dr. Freedman, reported a value of 72. For every megaparsec farther away from us that a galaxy is, it is moving 72 kilometers per second faster.

More recent efforts by Adam G. Riess, of Johns Hopkins and the Space Telescope Science Institute, and others have obtained similar numbers, and astronomers now say they have narrowed the uncertainty in the Hubble constant to just 2.4 percent.

But new precision has brought new trouble. These results are so good that they now disagree with results from the European Planck spacecraft, which predict a Hubble constant of 67.

The discrepancy — 9 percent — sounds fatal but may not be, astronomers contend, because Planck and human astronomers do very different kinds of observations.

Planck is considered the gold standard of cosmology. It spent four years studying the cosmic bath of microwaves left over from the end of the Big Bang, when the universe was just 380,000 years old. But it did not measure the Hubble constant directly. Rather, the Planck group derived the value of the constant, and other cosmic parameters, from a mathematical model largely based on those microwaves.

In short, Planck’s Hubble constant is based on a cosmic baby picture. In contrast, the classical astronomical value is derived from what cosmologists modestly call “local measurements,” a few billion light-years deep into a middle-aged universe.

What if that baby picture left out or obscured some important feature of the universe? 

‘Cosmological Whac-a-Mole’
And so cosmologists are off to the game that Lloyd Knox, an astrophysicist from the University of California, Davis, called “cosmological Whac-a-Mole” at the recent Chicago meeting: attempting to fix the model of the early universe, to make it expand a little faster without breaking what the model already does well.

One approach, some astrophysicists suggest, is to add more species of lightweight subatomic particles, such as the ghostlike neutrinos, to the early universe. (Physicists already recognize three kinds of neutrinos, and argue whether there is evidence for a fourth variety.) These would give the universe more room to stash energy, in the same way that more drawers in your dresser allow you to own more pairs of socks. Thus invigorated, the universe would expand faster, according to the Big Bang math, and hopefully not mess up the microwave baby picture.

A more drastic approach, from the Johns Hopkins group, invokes fields of exotic anti-gravitational energy. The idea exploits an aspect of string theory, the putative but unproven “theory of everything” that posits that the elementary constituents of reality are very tiny, wriggling strings.
String theory suggests that space could be laced with exotic energy fields associated with lightweight particles or forces yet undiscovered. Those fields, collectively called quintessence, could act in opposition to gravity, and could change over time — popping up, decaying or altering their effect, switching from repulsive to attractive.

The team focused in particular on the effects of fields associated with hypothetical particles called axions. Had one such field arisen when the universe was about 100,000 years old, it could have produced just the right amount of energy to fix the Hubble discrepancy, the team reported in a paper late last year. They refer to this theoretical force as “early dark energy.”

“I was surprised how it came out,” said Marc Kamionkowski, a Johns Hopkins cosmologist who was part of the study. “This works.”

The jury is still out. Dr. Riess said that the idea seems to work, which is not to say that he agrees with it, or that it is right. Nature, manifest in future observations, will have the final say.

Dr. Knox called the Johns Hopkins paper “an existence proof” that the Hubble problem could be solved. “I think that’s new,” he said.

Dr. Randall, however, has taken issue with aspects of the Johns Hopkins calculations. She and a trio of Harvard postdocs are working on a similar idea that she says works as well and is mathematically consistent. “It’s novel and very cool,” Dr. Randall said.

So far, the smart money is still on cosmic confusion. Michael Turner, a veteran cosmologist at the University of Chicago and the organizer of a recent airing of the Hubble tensions, said, “Indeed, all of this is going over all of our heads. We are confused and hoping that the confusion will lead to something good!” 

Doomsday? Nah, nevermind
Early dark energy appeals to some cosmologists because it hints at a link to, or between, two mysterious episodes in the history of the universe. As Dr. Riess said, “This is not the first time the universe has been expanding too fast.”

The first episode occurred when the universe was less than a trillionth of a trillionth of a second old. At that moment, cosmologists surmise, a violent ballooning propelled the Big Bang; in a fraction of a trillionth of a second, this event — named “inflation” by the cosmologist Alan Guth, of M.I.T. — smoothed and flattened the initial chaos into the more orderly universe observed today. Nobody knows what drove inflation.

The second episode is unfolding today: cosmic expansion is speeding up. But why? The issue came to light in 1998, when two competing teams of astronomers asked whether the collective gravity of the galaxies might be slowing the expansion enough to one day drag everything together into a Big Crunch.

To great surprise, they discovered the opposite: the expansion was accelerating under the influence of an anti-gravitational force later called dark energy. The two teams won a Nobel Prize.

Dark energy comprises 70 percent of the mass-energy of the universe. And, spookily, it behaves very much like a fudge factor known as the cosmological constant, a cosmic repulsive force that Einstein inserted in his equations a century ago thinking it would keep the universe from collapsing under its own weight. He later abandoned the idea, perhaps too soon.

Under the influence of dark energy, the cosmos is now doubling in size every 10 billion years — to what end, nobody knows.

Early dark energy, the force invoked by the Johns Hopkins group, might represent a third episode of antigravity taking over the universe and speeding it up. Perhaps all three episodes are different manifestations of the same underlying tendency of the universe to go rogue and speed up occasionally. In an email, Dr. Riess said, “Maybe the universe does this from time-to-time?”

If so, it would mean that the current manifestation of dark energy is not Einstein’s constant after all. It might wink off one day. That would relieve astronomers, and everybody else, of an existential nightmare regarding the future of the universe. If dark energy remains constant, everything outside our galaxy eventually will be moving away from us faster than the speed of light, and will no longer be visible. The universe will become lifeless and utterly dark.

But if dark energy is temporary — if one day it switches off — cosmologists and metaphysicians can all go back to contemplating a sensible tomorrow.

“An appealing feature of this is that there might be a future for humanity,” said Scott Dodelson, a theorist at Carnegie Mellon who has explored similar scenarios. 

The phantom cosmos
But the future is still up for grabs.

Far from switching off, the dark energy currently in the universe actually has increased over cosmic time, according to a recent report in Nature Astronomy. If this keeps up, the universe could end one day in what astronomers call the Big Rip, with atoms and elementary particles torn asunder — perhaps the ultimate cosmic catastrophe.

This dire scenario emerges from the work of Guido Risaliti, of the University of Florence in Italy, and Elisabeta Lusso, of Durham University in England. For the last four years, they have plumbed the deep history of the universe, using violent, faraway cataclysms called quasars as distance markers.

Quasars arise from supermassive black holes at the centers of galaxies; they are the brightest objects in nature, and can be seen clear across the universe. As standard candles, quasars aren’t ideal because their masses vary widely. Nevertheless, the researchers identified some regularities in the emissions from quasars, allowing the history of the cosmos to be traced back nearly 12 billion years. The team found that the rate of cosmic expansion deviated from expectations over that time span.

One interpretation of the results is that dark energy is not constant after all, but is changing, growing denser and thus stronger over cosmic time. It so happens that this increase in dark energy also would be just enough to resolve the discrepancy in measurements of the Hubble constant.

The bad news is that, if this model is right, dark energy may be in a particularly virulent and — most physicists say — implausible form called phantom energy. Its existence would imply that things can lose energy by speeding up, for instance. Robert Caldwell, a Dartmouth physicist, has referred to it as “bad news stuff.”

As the universe expands, the push from phantom energy would grow without bounds, eventually overcoming gravity and tearing apart first Earth, then atoms.

The Hubble-constant community responded to the new report with caution. “If it holds up, this is a very interesting result,” said Dr. Freedman.

Astronomers have been trying to take the measure of this dark energy for two decades. Two space missions — the European Space Agency’s Euclid and NASA’s Wfirst — have been designed to study dark energy and hopefully deliver definitive answers in the coming decade. The fate of the universe is at stake.

In the meantime, everything, including phantom energy, is up for consideration, according to Dr. Riess.

“In a list of possible solutions to the tension via new physics, mentioning weird dark energy like this would seem appropriate,” he wrote in an email. “Heck, at least their dark energy goes in the right direction to solve the tension. It could have gone the other way and made it worse!”

Monday, 18 February 2019

Indians trace their identity from a much more hybrid ancestry (than ideologues would have us believe)

Your book argues that today’s tribals should be seen as the foundational population of India. Can you explain that further for our readers?

Image result for Early Indians
The ancestry of the First Indians, that is those who arrived in India around 65,000 years ago, accounts for 50 to 65% of the ancestry of all Indian population groups, no matter where in the caste hierarchy they stand, what language they speak, or which region they inhabit. Many tribal populations, in a relative sense, carry this ancestry to a higher level than other Indians, and to that extent, they can be seen as the foundational population of India. But the more important point is this: The tribals share their ancestry with the rest of the Indian population and so they are closely and intimately related to “us.” Therefore, there is zero basis to continue to see them as different from the rest of the Indians in any way. To those who ask, “where did the First Indians go,” or “where are they today,” the answer is: look in the mirror!

Given that the idea of there once being a pure, original type of Indian is being increasingly used to fuel a political narrative, what is it that you want readers to take away from your book?
That the Indian population was shaped by four, large prehistoric migrations. The first involved the Out of Africa (OoA) migrants who reached India about 65,000 years ago and whom my book calls First Indians. The second involved agriculturists from the Zagros region of Iran who arrived in northwestern India between 7000 and 3000 BCE, mixed with the First Indians and helped speed up the agricultural experiments that were already beginning in the subcontinent. The result was that farming spread like wildfire across the northwestern region, especially of barley and wheat, thus laying the foundation for the Harappan Civilisation that lasted in its mature phase from 2600 BCE to 1900 BCE. The third major migration was from southeast Asia around 2000 BCE, when farming-related population expansions originally starting from the Chinese heartland overran southeast Asia and then reached India, bringing the Austroasiatic family of languages, such as Mundari and Khasi which are today spoken in the eastern and central parts of the country. The last, or the fourth, major migration happened between 2000 and 1000 BCE and this brought Central Asian pastoralists, who spoke Indo-European languages and called themselves “Aryans” to India. There was large-scale mixing between these different population groups between around 2000 and 100 CE. Around 100 BCE there seems to have been a change in the reigning political ideology and, as a result, mixing between different population groups stopped, and this is probably linked to the beginning of the caste system. So the central message of the book is that we are all descendants of migrants who mixed and mingled with each other for millennia, before the caste system fell into place. We are all kin. That is the message for readers to take away. 

Can you tell us more about how technology has helped the process of uncovering such “origins”?
What has really changed the nature of the discoveries is ancient DNA, or aDNA. Earlier, population genetics studies could discover affinities between population groups, but they could not conclusively settle the issue of the direction of movement of people. They could make intelligent deductions that most scientists would agree with, but they could not settle the issue. But when you have access to aDNA from the same location at different time periods, or when you have access to aDNA from different adjacent sites from the same period, you can see on the ground who moved when and where. This has radically changed our understanding of population movements, culture change, and prehistory in general. When we put this new aDNA findings together with the latest findings of archaeology, linguistics, epigraphy, and philology, we get a robust understanding of prehistory—as I said, not just in India, but across the world. The prehistory of Europe, East Asia, and the Americas are also being rewritten as we speak.

What are some of the difficulties in tracing this story in a place like India?
Some parts of our prehistory are part of current political conversation, and that makes it very difficult for scientists to do their work with the kind of openness and frankness that is otherwise common in scientific disciplines. This applies mostly to the topic of “Aryan” migration. There is an extraordinary level of sensitivity that is attached to this topic that is unique and surprising. As I had written elsewhere, “You could stand in the middle of a crowded market in Hyderabad, Bengaluru, Chennai, or Kochi and say that the common ancestor of the languages Kannada, Telugu, Tamil, and Malayalam was brought to India by migrants from west Asia some 8,000 years ago, and no one is likely to care or protest. You could stand in the middle of Jharkhand and say that Austroasiatic languages such as Mundari, Santali, and Ho came to India from southeast Asia around 4000 years ago, and no one is likely to raise a finger against you. You can stand anywhere in India and say that the earliest Indians were Out of Africa migrants who reached south Asia some 65,000 years ago and no one would really mind.

But if you were to say that an early version of Sanskrit was brought to India from central Asia by pastoralists who called themselves ‘Aryans,’ expect the skies to open and pour condemnation down on you.

The reason for this special touchiness, I think, is the assumption that the ‘Aryan,’ or Vedic or Sanskrit culture is synonymous with Indian culture and to suggest that it may have come from elsewhere is to suggest that Indian culture is foreign! But this is a ridiculous assumption on various counts. First of all, Indian culture is not synonymous with, or identical to, ‘Aryan’ or ‘Sanskrit’ or ‘Vedic’ culture. ‘Aryan’ culture was an important stream that contributed to creating the unique Indian civilisation as we know it today, but by no means was it the only one. There are other streams that have contributed equally to making Indian civilisation what it is, such as the Harappan Civilisation that preceded the ‘Aryans.’ Second, to say that Indo-European languages reached India at a particular historical juncture is not the same as suggesting that the ‘Vedas’ or ‘Sanskrit’ or the ‘Aryan’ culture was imported flat-packed and then reassembled here. ‘Aryan’ culture was most likely the result of interaction, adoption and adaptation among those who brought Indo-European languages to India and those who were already well-settled inhabitants of the region.”