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The genes of the oldest known residents of the Caribbean link them with the earliest populations that settled in Central and South America.

Part of the problem is that scientists have yet to find ancient DNA in the Caribbean that is more than 3,000 years old

The other problem is that ancient DNA is still scarce on the Caribbean coast of the mainland.

About 2,500 years ago, the archaeological record shows, there was a drastic shift in the cultural life of the Caribbean. People started living in bigger settlements, intensively farming crops like maize and sweet potatoes. Their pottery became more sophisticated and elaborate. For archaeologists, the change indicates the end of what they call the Archaic Age and the start of a Ceramic Age.

The skeletons from the Ceramic Age largely shared a new genetic signature. Their DNA links them to small tribes still living today in Colombia and Venezuela.

We don’t know a lot about these languages, although some words have managed to survive. Hurricane, for example, comes from hurakán, the Taino name for the god of storms.

The people bearing Ceramic Age ancestry came to dominate the Caribbean, with almost no interbreeding between the two groups.

These words bear a striking resemblance to words from a family of languages in South America called Arawak. The DNA of the Ceramic Age Caribbeans most closely resembles that of living Arawak speakers.

the new DNA findings had surprised him in many ways, giving him a host of new questions to investigate.

Over the course of the Ceramic Age, for example, strikingly new pottery styles emerged every few centuries. Researchers have long guessed that those shifts reflect the arrival of new groups of people in the islands. The ancient DNA doesn’t support that idea, though. There’s a genetic continuity through those drastic cultural changes. It appears that the same group of people in the Caribbean went through a series of major social changes that archaeologists have yet to explain.

Dr. Reich and his fellow geneticists also discovered family ties that spanned the Caribbean during the Ceramic Age. They found 19 pairs of people on different islands who shared identical segments of DNA — a sign that they were fairly close relatives. In one case, they found long-distance cousins from the Bahamas and Puerto Rico, separated by over 800 miles.

“The original idea was that people start in one place, they establish a colony someplace else, and then they just cut all ties to where they came from,” Dr. Keegan said. “But the genetic evidence is suggesting that these ties were maintained over a long period of time.”

Rather than being made up of isolated communities, in other words, the Caribbean was a busy, long-distance network that people regularly traveled by dugout canoe. “The water is like a highway,”

The genetic variations also allowed Dr. Reich and his colleague to estimate the size of the Caribbean society before European contact. Christopher Columbus’s brother Bartholomew sent letters back to Spain putting the figure in the millions

The DNA suggests that was an exaggeration: the genetic variations imply that the total population was as low as the tens of thousands.

now, with a population of about 44 million people, the Caribbean may contain more Taino DNA than it did in 1491.

Dr. Aviles and his colleagues have uploaded the ancient Caribbean genomes to a genealogical database called GEDMatch. With the help of genealogists, people can compare their own DNA to the ancient genomes. They can see the matching stretches of genetic material that reveal their relatedness.

Argentina joins a small group of Latin American and Caribbean countries that have legalized elective abortion, including Uruguay, Cuba and Guyana.

in mid-November. Fernández, who was elected in late 2019, has been vocal about legalizing abortion during his presidency and says he will sign the measure.

"Today we are a better society that expands rights to women and guarantees public health," Fernández wrote after the legislation passed.

In 2018 and 2020, people backing the legalization have sported green clothing and often held or worn green bandannas — a visual that has become linked with the movement.

Despite being largely illegal throughout the region, about 5.4 million abortions occurred annually in Latin America and the Caribbean between 2015 and 2019, the Guttmacher Institute reported.

The United States has one of the world’s largest pay gaps, with chief executives earning nearly 300 times what the average worker makes, according to some economists’ estimates. That is much higher than the 20-to-1 ratio recommended by Gilded Age magnates like J. Pierpont Morgan and the 20th century management visionary Peter Drucker.

“The market rate for me as a C.E.O. compared to a regular person is ridiculous, it’s absurd,” said Mr. Price, who said his main extravagances were snowboarding and picking up the bar bill. He drives a 12-year-old Audi

Under a financial overhaul passed by Congress in 2010, the Securities and Exchange Commission was supposed to require all publicly held companies to disclose the ratio of C.E.O. pay to the median pay of all other employees, but it has so far failed to put it in effect. Corporate executives have vigorously opposed the idea, complaining it would be cumbersome and costly to implement.

Of all the social issues that he felt he was in a position to do something about as a business leader, “that one seemed like a more worthy issue to go after.”

The happiness research behind Mr. Price’s announcement on Monday came from Angus Deaton and Daniel Kahneman, a Nobel Prize-winning psychologist. They found that what they called emotional well-being — defined as “the emotional quality of an individual’s everyday experience, the frequency and intensity of experiences of joy, stress, sadness, anger, and affection that make one’s life pleasant or unpleasant” — rises with income, but only to a point. And that point turns out to be about $75,000 a year.

Of course, money above that level brings pleasures — there’s no denying the delights of a Caribbean cruise or a pair of diamond earrings — but no further gains on the emotional well-being scale.

As Mr. Kahneman has explained it, income above the threshold doesn’t buy happiness, but a lack of money can deprive you of it.

The same technology that renders humans useless might also make it feasible to feed and support the unemployable masses through some scheme of universal basic income.

The real problem will then be to keep the masses occupied and content. People must engage in purposeful activities, or they go crazy. So what will the useless class do all day?

One answer might be computer games. Economically redundant people might spend increasing amounts of time within 3D virtual reality worlds, which would provide them with far more excitement and emotional engagement than the “real world” outside.

This, in fact, is a very old solution. For thousands of years, billions of people have found meaning in playing virtual reality games. In the past, we have called these virtual reality games “religions”.

Muslims and Christians go through life trying to gain points in their favorite virtual reality game. If you pray every day, you get points. If you forget to pray, you lose points. If by the end of your life you gain enough points, then after you die you go to the next level of the game (aka heaven).

As religions show us, the virtual reality need not be encased inside an isolated box. Rather, it can be superimposed on the physical reality. In the past this was done with the human imagination and with sacred books, and in the 21st century it can be done with smartphones.

Consumerism too is a virtual reality game. You gain points by acquiring new cars, buying expensive brands and taking vacations abroad, and if you have more points than everybody else, you tell yourself you won the game.

we saw two others kids on the street who were hunting the same Pokémon, and we almost got into a fight with them. It struck me how similar the situation was to the conflict between Jews and Muslims about the holy city of Jerusalem. When you look at the objective reality of Jerusalem, all you see are stones and buildings. There is no holiness anywhere. But when you look through the medium of smartbooks (such as the Bible and the Qur’an), you see holy places and angels everywhere.

In the end, the real action always takes place inside the human brain. Does it matter whether the neurons are stimulated by observing pixels on a computer screen, by looking outside the windows of a Caribbean resort, or by seeing heaven in our mind’s eyes?

Indeed, one particularly interesting section of Israeli society provides a unique laboratory for how to live a contented life in a post-work world. In Israel, a significant percentage of ultra-orthodox Jewish men never work. They spend their entire lives studying holy scriptures and performing religion rituals. They and their families don’t starve to death partly because the wives often work, and partly because the government provides them with generous subsidies. Though they usually live in poverty, government support means that they never lack for the basic necessities of life.

That’s universal basic income in action. Though they are poor and never work, in survey after survey these ultra-orthodox Jewish men report higher levels of life-satisfaction than any other section of Israeli society.

Hence virtual realities are likely to be key to providing meaning to the useless class of the post-work world. Maybe these virtual realities will be generated inside computers. Maybe they will be generated outside computers, in the shape of new religions and ideologies. Maybe it will be a combination of the two. The possibilities are endless

In any case, the end of work will not necessarily mean the end of meaning, because meaning is generated by imagining rather than by working.

People in 2050 will probably be able to play deeper games and to construct more complex virtual worlds than in any previous time in history.

But what about truth? What about reality? Do we really want to live in a world in which billions of people are immersed in fantasies, pursuing make-believe goals and obeying imaginary laws? Well, like it or not, that’s the world we have been living in for thousands of years already.

‘Listen, I have all this vaccine. And people are afraid to get it here,’” Ms. Platten recalled. “‘If you have any friends, or there’s anyone you know who wants a vaccine, please have them call me.’”

“The result has been a mini boom of visitors on an island whose tourism economy, like most others, has been brutalized by the pandemic.”

“Nowhere else in the U.S. can you actually just walk in and get the vaccine, anybody over 16,” Mr. Bryan said on Monday. On March 1, the islands also opened two federally supported community vaccination centers on St. Thomas and St. Croix.

“On the public health side, it’s a plus,” she said. “On the equity side, I don’t see it as significant issue.”

These communities, with generations of experience successfully protecting nature, have strong track records of guarding the forest, according to the report. They generally favor smaller-scale, more diverse farming, which extracts far less from the land than industrial operations do. 

“The forest provides us food, water and gives us a roof. It’s not something alien to us, but another living being,” said Rivas, who’s also been working to promote gender equality in the agroforestry sector. “We only take what we need, nothing more.”

“We need to center and take direction from Indigenous and tribal earth defenders in order to protect forests’ biodiversity and even prevent the next pandemic,”

“This scientific consensus [in the report] gives our world’s leaders a mandate to defend the rights of Indigenous and tribal communities,” said Recinos. “Otherwise, sensitive biomes and rainforests, such as the Amazon, will remain under threat or, worse, reach an irreversible tipping point.” 

Globally, the numbers can be even worse, and the stakes often higher. “Say a person comes into the hospital in Sierra Leone with a fever and flulike symptoms,” DeRisi says. “After a few days, or a week, they die. What caused that illness? Most of the time, we never find out. Because if the cause isn’t something that we can culture and test for” — like hepatitis, or strep throat — “it basically just stays a mystery.”

It would be better, DeRisi says, to watch for rare cases of mystery illnesses in people, which often exist well before a pathogen gains traction and is able to spread.

Based on a retrospective analysis of blood samples, scientists now know that H.I.V. emerged nearly a dozen times over a century, starting in the 1920s, before it went global.

Zika was a relatively harmless illness before a single mutation, in 2013, gave the virus the ability to enter and damage brain cells.

The beauty of this approach” — running blood samples from people hospitalized all over the world through his system, known as IDseq — “is that it works even for things that we’ve never seen before, or things that we might think we’ve seen but which are actually something new.”

In this scenario, an undiscovered or completely new virus won’t trigger a match but will instead be flagged. (Even in those cases, the mystery pathogen will usually belong to a known virus family: coronaviruses, for instance, or filoviruses that cause hemorrhagic fevers like Ebola and Marburg.)

And because different types of bacteria require specific conditions in order to grow, you also need some idea of what you’re looking for in order to find it.

The same is true of genomic sequencing, which relies on “primers” designed to match different combinations of nucleotides (the building blocks of DNA and RNA).

Even looking at a slide under a microscope requires staining, which makes organisms easier to see — but the stains used to identify bacteria and parasites, for instance, aren’t the same.

The practice that DeRisi helped pioneer to skirt this problem is known as metagenomic sequencing

Unlike ordinary genomic sequencing, which tries to spell out the purified DNA of a single, known organism, metagenomic sequencing can be applied to a messy sample of just about anything — blood, mud, seawater, snot — which will often contain dozens or hundreds of different organisms, all unknown, and each with its own DNA. In order to read all the fragmented genetic material, metagenomic sequencing uses sophisticated software to stitch the pieces together by matching overlapping segments.

The assembled genomes are then compared against a vast database of all known genomic sequences — maintained by the government-run National Center for Biotechnology Information — making it possible for researchers to identify everything in the mix

Traditionally, the way that scientists have identified organisms in a sample is to culture them: Isolate a particular bacterium (or virus or parasite or fungus); grow it in a petri dish; and then examine the result under a microscope, or use genomic sequencing, to understand just what it is. But because less than 2 percent of bacteria — and even fewer viruses — can be grown in a lab, the process often reveals only a tiny fraction of what’s actually there. It’s a bit like planting 100 different kinds of seeds that you found in an old jar. One or two of those will germinate and produce a plant, but there’s no way to know what the rest might have grown into.

Such studies have revealed just how vast the microbial world is, and how little we know about it

“The selling point for researchers is: ‘Look, this technology lets you investigate what’s happening in your clinic, whether it’s kids with meningitis or something else,’” DeRisi said. “We’re not telling you what to do with it. But it’s also true that if we have enough people using this, spread out all around the world, then it does become a global network for detecting emerging pandemics

One study found more than 1,000 different kinds of viruses in a tiny amount of human stool; another found a million in a couple of pounds of marine sediment. And most were organisms that nobody had seen before.

After the Biohub opened in 2016, one of DeRisi’s goals was to turn metagenomics from a rarefied technology used by a handful of elite universities into something that researchers around the world could benefit from

metagenomics requires enormous amounts of computing power, putting it out of reach of all but the most well-funded research labs. The tool DeRisi created, IDseq, made it possible for researchers anywhere in the world to process samples through the use of a small, off-the-shelf sequencer, much like the one DeRisi had shown me in his lab, and then upload the results to the cloud for analysis.

he’s the first to make the process so accessible, even in countries where lab supplies and training are scarce. DeRisi and his team tested the chemicals used to prepare DNA for sequencing and determined that using as little as half the recommended amount often worked fine. They also 3-D print some of the labs’ tools and replacement parts, and offer ongoing training and tech support

The metagenomic analysis itself — normally the most expensive part of the process — is provided free.

But DeRisi’s main innovation has been in streamlining and simplifying the extraordinarily complex computational side of metagenomics

IDseq is also fast, capable of doing analyses in hours that would take other systems weeks.

“What IDseq really did was to marry wet-lab work — accumulating samples, processing them, running them through a sequencer — with the bioinformatic analysis,”

“Without that, what happens in a lot of places is that the researcher will be like, ‘OK, I collected the samples!’ But because they can’t analyze them, the samples end up in the freezer. The information just gets stuck there.”

Meningitis itself isn’t a disease, just a description meaning that the tissues around the brain and spinal cord have become inflamed. In the United States, bacterial infections can cause meningitis, as can enteroviruses, mumps and herpes simplex. But a high proportion of cases have, as doctors say, no known etiology: No one knows why the patient’s brain and spinal tissues are swelling.

When Saha and her team ran the mystery meningitis samples through IDseq, though, the result was surprising. Rather than revealing a bacterial cause, as expected, a third of the samples showed signs of the chikungunya virus — specifically, a neuroinvasive strain that was thought to be extremely rare. “At first we thought, It cannot be true!” Saha recalls. “But the moment Joe and I realized it was chikungunya, I went back and looked at the other 200 samples that we had collected around the same time. And we found the virus in some of those samples as well.”

Until recently, chikungunya was a comparatively rare disease, present mostly in parts of Central and East Africa. “Then it just exploded through the Caribbean and Africa and across Southeast Asia into India and Bangladesh,” DeRisi told me. In 2011, there were zero cases of chikungunya reported in Latin America. By 2014, there were a million.

Chikungunya is a mosquito-borne virus, but when DeRisi and Saha looked at the results from IDseq, they also saw something else: a primate tetraparvovirus. Primate tetraparvoviruses are almost unknown in humans, and have been found only in certain regions. Even now, DeRisi is careful to note, it’s not clear what effect the virus has on people. “Maybe it’s dangerous, maybe it isn’t,” DeRisi says. “But I’ll tell you what: It’s now on my radar.

it reveals a landscape of potentially dangerous viruses that we would otherwise never find out about. “What we’ve been missing is that there’s an entire universe of pathogens out there that are causing disease in humans,” Imam notes, “ones that we often don’t even know exist.”

“The plan was, Let’s let researchers around the world propose studies, and we’ll choose 10 of them to start,” DeRisi recalls. “We thought we’d get, like, a couple dozen proposals, and instead we got 350.”

Metagenomic sequencing is especially good at what scientists call “environmental sampling”: identifying, say, every type of bacteria present in the gut microbiome, or in a teaspoon of seawater.

“When you draw blood from someone who has a fever in Ghana, you really don’t know very much about what would normally be in their blood without fever — let alone about other kinds of contaminants in the environment. So how do you interpret the relevance of all the things you’re seeing?”

Such criticisms have led some to say that metagenomics simply isn’t suited to the infrastructure of developing countries. Along with the problem of contamination, many labs struggle to get the chemical reagents needed for sequencing, either because of the cost or because of shipping and customs holdups

we’re less likely to be caught off-guard. “With Ebola, there’s always an issue: Where’s the virus hiding before it breaks out?” DeRisi explains. “But also, once we start sampling people who are hospitalized more widely — meaning not just people in Northern California or Boston, but in Uganda, and Sierra Leone, and Indonesia — the chance of disastrous surprises will go down. We’ll start seeing what’s hidden.”