The Best American Science and Nature Writing 2020

by Michio Kaku

  What if some much later iteration of GPT-2, far more powerful than this model, could be hybridized with a procedural system, so that it would be able to write causally and distinguish truth from fiction and at the same time draw from its well of deep learning? One can imagine a kind of Joycean super-author, capable of any style, turning out spine-tingling suspense novels, massively researched biographies, and nuanced analyses of the Israeli-Palestinian conflict. Humans would stop writing, or at least publishing, because all the readers would be captivated by the machines. What then?

  GPT-2, prompted with that paragraph, predicted the next sentence: “In a way, the humans would be making progress.”

  JOSHUA SOKOL

  Troubled Treasure

  from Science Magazine

  On an overcast spring morning, a mosaic of life in the heyday of the dinosaurs takes shape piece by piece in this border city [Tengchong, China]. It sprawls across hundreds of tables, on sheets spread by storefronts, and under glass counters in shops. Some vendors hawk jade or snacks, but most everyone is here for the amber: raw amber coated in gray volcanic ash; polished amber carved into smiling Buddhas; egg-size dollops of amber the color of honey, molasses, or garnet. Some browsers seek treasure for their own collections, whereas others act as virtual dealers, holding amber pieces in front of their smartphones and snapping images for distant buyers.

  For scientists, this is more than a place to buy pendants or bracelets. One morning in March, paleontologist Xing Lida from the China University of Geosciences in Beijing stops at a table and examines a cockroach in a golf ball–size glob of amber, paused in time from the middle of the Cretaceous period. Its intact limbs curve off a body that looks smaller and narrower than that of today’s household pests.

  The dealer wants about $900. “It’s an okay price,” Xing says. But he moves on, hunting rarer, more scientifically valuable game.

  Within a few minutes, a stranger notices Xing, shoots video of him, and posts it to social media. With 2.6 million followers on Weibo, a Chinese hybrid of Facebook and Twitter, the baby-faced, hypercharismatic Xing is a celebrity for his studies of dinosaur tracks and other adventures (Science, June 23, 2017, p. 1224). Last year, he published twenty-five scientific papers and a dinosaur-related fantasy novel with a foreword by Liu Cixin, the country’s superstar science fiction author. But Xing, like a few other Chinese paleontologists, is also lionized for the extraordinary discoveries he has made in this amber: the hatchlings of primitive birds, the feathered tail of a dinosaur, lizards, frogs, snakes, snails, a host of insects. Much as nineteenth-century naturalists collected species from teeming rain forests in far-flung locales, these scientists are building a detailed chronicle of life in a tropical forest 100 million years ago, all from amber mined across the border in Myanmar.

  “Right now we’re in this frenzy, almost an orgy” of discovery, says paleontologist David Grimaldi, curator of the amber collection at the American Museum of Natural History in New York City. Hundreds of scientific papers have emerged from the amber finds, and Chinese scientists hint that many specimens have yet to be published, including birds, insect species by the thousands, and even aquatic animals such as crabs or salamanders.

  But as much as Burmese amber is a scientist’s dream, it’s also an ethical minefield. The fossils come from conflict-ridden Kachin state in Myanmar, where scientists can’t inspect the geology for clues to the fossils’ age and environment. In Kachin, rival political factions compete for the profit yielded by amber and other natural resources. “These commodities are fueling the conflict,” says Paul Donowitz, the Washington, D.C.–based campaign leader for Myanmar at Global Witness, a nongovernmental organization. “They are providing revenue for arms and conflict actors, and the government is launching attacks and killing people and committing human rights abuses to cut off those resources.”

  Much of the amber is smuggled into China in a trade that Tengchong officials and traders ballparked at between $725 million and $1 billion in 2015 alone. In China, jewelers, private collectors, and scientists like Xing exchange vast sums of cash through mobile payment apps to compete for prized specimens. The collectors often win the bidding, meaning researchers can study many specimens only on loan.

  The mixture of commerce and science “raises new questions that we have not faced . . . in paleontology before,” says Julia Clarke, a paleontologist at the University of Texas in Austin who often edits papers on Burmese amber. But given that the amber will be sold even if scientists don’t buy in, she says, “What’s the other prospective outcome?”

  That’s what drives Xing to the market. “If we don’t get a specimen, it probably becomes cheap jewelry around some young girl’s neck.”

  * * *

  Some 99 million years before this spring market and about 220 kilometers away in what is now Myanmar, a balmy seaside forest echoed with the calls of strange creatures. The trees bled massive quantities of resin when insects attacked them or storms broke off limbs. The resin puddled and pooled, miring countless creatures “like a mini–La Brea Tar Pits,” says paleontologist Ryan McKellar at the Royal Saskatchewan Museum in Regina, Canada. Over time, the resin’s frankincense-like gases evaporated; its molecules linked into polymers and hardened into what we now call amber.

  Amber excels at preserving fine detail and soft tissue, says Victoria McCoy, a paleontologist at the University of Bonn in Germany. On contact, resin seeps into tissues, protecting the entombed animals and plants from fungus and rot while also drying them out. Later, the resin hardens to form a shell that further protects the fossil inclusions. In the best cases, “cellular- or even subcellular-level details are still preserved,” she says.

  Amber from other major deposits—​specimens that wash up on beaches in Baltic countries or are mined in the Dominican Republic—​is far younger. It also rarely traps strong, active creatures, such as dragonflies, or any vertebrates beyond a few lizards.

  Burmese amber, in contrast, has revealed a phantasmagoria of creatures, thanks to the vast quantities coming out of the ground and the fact that single pieces regularly approach the size of cantaloupes. As Grimaldi expresses it: imagine giving an entomologist a bigger bug net and allowing them to swing it more times. It’s not just insects and other creepy-crawlies. “It’s the vertebrates that are absolutely, truly astonishing,” says Andrew Ross, head of paleobiology for National Museums Scotland in Edinburgh.

  In 2018, scientists reported 321 new species immaculately preserved in Burmese amber, bringing the cumulative total to 1,195. One team recently argued that Burmese amber may boast more biodiversity than any other fossil deposit from the entire reign of the dinosaurs. “You think this can’t even be possible,” says Philip Currie, a paleontologist at the University of Alberta in Edmonton, Canada, “but it’s happening.”

  Single fossils within that bonanza illuminate how creatures lived and where they fit into the tree of life. Taken together, the finds benchmark the birth of lineages and ecological relationships that still undergird modern ecosystems.

  Most of that scientific bounty passes through the bustling market here in Tengchong. And before that, it emerges from a conflict zone.

  * * *

  In 2014, Xing sneaked into Myanmar, hoping to see the source of the specimens that had captivated him. The amber comes from mines near Tanai township in Kachin, where for decades Myanmar’s army and the local Kachin Independence Army, an ethnic insurgency, have battled over control of lucrative resources such as jade, timber, and, most recently, amber. Foreigners are not allowed into Tanai. To make his clandestine visit, Xing first traveled across the border some 110 kilometers to Myitkyina, the Myanmar-side hub of the amber trade. When the road seemed safe, a friend smuggled him north dressed in a longyi, a traditional Myanmarese wrap skirt.

  Xing and other visitors to the mines describe a lush terrain transformed into barren hillsides. Tents cover claustrophobic holes up to 100 meters deep but only wide enough for skinny workers, who say they are re
sponsible for their own medical care after accidents. The miners dig down and, when they hit layers of amber, tunnel horizontally with hand tools to dig it out. They sort finds at night, to avoid publicizing valuable discoveries. Amber with fossil inclusions is the most precious, proof after weeks of uncertainty that a mine will be profitable. Reached by phone through an interpreter, miners say both warring sides demand bribes for the rights to an area and equipment—​and then tax 10 percent of the profit.

  Xing hasn’t yet published his full conclusions from that trip, but he and others suspect the origins of the amber may be more complicated than thought. The oft-quoted age of 99 million years comes from radiometric dating of volcanic ash bought from a miner and published in 2012. But Wang Bo, a paleontologist at Nanjing Institute of Geology and Palaeontology (NIGPAS) in China, thinks the recent wave of amber has a range of ages. He had a friend with Myanmarese citizenship gather more recent samples of volcanic ash, which Wang says show that the amber deposits span at least 5 million years. “It’s a period,” he says, “not just a point.”

  Miners and traders aren’t concerned with details of geology, however. After the amber is extracted and roughly sorted, scooters, cars, boats, and elephants carry it to dealers either in Myitkyina or straight across the border to Tengchong. Myanmar law explicitly bars exporting fossils without permission—​but amber is classified as a gemstone and so is allowed to leave.

  China, however, taxes jewelry imports, so dealers here say they smuggle amber in—​for example, in the wheel wells of cars. In Tengchong’s market that “shadow economy” emerges into broad daylight, wrote anthropologist Alessandro Rippa at the University of Colorado in Boulder in a 2017 anthropological study. Local authorities not only tolerate, but police the market, which has been an economic boon.

  Scientists didn’t take long to notice. Since the 1920s, a small collection at London’s Natural History Museum offered scientists their only glimpse of the diversity of life inside Burmese amber. Then, during a cease-fire in the late 1990s, a small Canadian company started to mine amber in Kachin. It shipped 75 kilograms of raw amber to Grimaldi. He found that each kilogram he acid-washed, cut, and polished contained an average of forty-six organisms. In the early 2010s, the market here started to boom just as amber mines inside China became tapped out. Demand rose for new amber sources—​and that trickle of amber fossils from Myanmar turned into a flood.

  * * *

  Before Xing’s March visit to the bustling outdoor market, he had already arranged to make a purchase after seeing pictures sent to his phone. Now, in a dimly lit amber jewelry shop, a camera-shy twenty-something broker from Myitkyina delivers today’s prize: two lizards in amber. On one, the skin and flesh have vanished in patches, revealing delicate bones. Given the pace of commerce here, a museum, with its bureaucracy and budgeting process, could never compete for that specimen. Xing simply takes out his smartphone and taps a payment app to buy it for a few hundred dollars—​a good deal, he says, because this piece is too cloudy and jumbled to make attractive jewelry.

  In 2014, Xing began to cultivate a network of buyers here and in Myitkyina and teach them to spot the claws of a Cretaceous bird wing or to count the toes that would tell whether a foot came from a lizard or a dinosaur. Once he gets a tip, he texts a picture to specialists, hoping to figure out whether a specimen’s likely scientific importance justifies steep prices. Only then will he decide to buy.

  Receiving Xing’s texts is “like Christmas every time,” McKellar says. Scientists are aware that their identifications can boost prices. Once a specimen has been named as a bird, for example, it might go for tens of thousands or even hundreds of thousands of dollars. Wang adds, “They will use my word to make money.”

  “In an ideal world, we shouldn’t be bartering and buying and selling fossils,” says paleontologist Emily Rayfield of the University of Bristol in the United Kingdom, president of the Society of Vertebrate Paleontology, paraphrasing that organization’s formal position. “But sometimes there’s a need to do that to keep them in, or bring them into, the public trust.”

  At first, Xing used his own money to buy fossils. Then he persuaded his parents, both doctors, to sell their house in southern China to free up cash. He spent that money by 2016, and he and friends started a nonprofit called the Dexu Institute of Palaeontology (DIP), based in the southern Guangdong province in China, to acquire and house a permanent collection that makes specimens available for other scientists.

  Xing has since published papers on enough vertebrates to fill a Cretaceous terrarium, including a baby snake fossil that preserved ninety-seven fragile vertebrae, published in Science Advances; the front half of a two-centimeter-long frog, in Scientific Reports; and his blockbuster result, a feathered dinosaur tail that appears to contain traces of hemoglobin, in Current Biology.

  But Xing’s first and most sustained success has been with tiny birds. Soon after he had built up his network, a source sent him a picture of the first bird discovered in amber. “The price was about the same as a new BMW, but we still got it,” he says. “And we found more, and more, and more after that.”

  The birds hail from a primitive group called Enantiornithes that went extinct with the other dinosaurs. Amber preserves never-before-seen features of their skin and feathers and may even reveal internal details. “This is a whole new window into avian evolution,” Clarke says.

  For example, other Chinese bird fossils exhibited flaring tail feathers that had been squished flat inside sedimentary rock. Paleontologists assumed those feathers matched similar ornamental ones in modern birds, which have a central shaft built like a hollow tube. In December 2018, though, Xing published feathers from thirty-one Burmese amber pieces, which revealed an open, superthin central shaft. Given that those flimsy feathers always appear straight in fossils, they must have been able to snap into a rigid state, like a child’s snap-on bracelet.

  “Now we know, from these 3-D amber specimens, that everything we think we see [from flattened fossils] is wrong,” says Jingmai O’Connor, who studies Xing’s bird fossils from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. In February, the team published another amber discovery: a bird’s foot topped with feathers—​an expected but previously unseen evolutionary step for modern birds, which later evolved scaly, featherless feet.

  The Jurassic Park dream of fishing out DNA from amber hasn’t yet come true, despite multiple tests in even very young amber, McCoy says. But amber researchers have reported other chemical traces lingering in their fossils: pigments that reveal how creatures shimmered under the mid-Cretaceous sun, and structural molecules such as chitin from arthropod exoskeletons and lignin and cellulose from plants. Last month, McCoy’s group reported recovering amino acids from a feather in Burmese amber, bearing a chemical signature that suggested they had still been bound into fragments of proteins before the test. The next step: to actually sequence ancient proteins, which could offer researchers another way to track evolutionary relationships and understand how organisms lived.

  But McCoy’s experiment involved smashing amber-clad feathers to powder with a hammer. Scientists—​and collectors—​would prefer other methods to study trapped biomolecules. Researchers have started to experiment with synchrotron imaging, using intense X-rays that cause chemical elements in a sample to fluoresce at distinct wavelengths, for example. “It’s going to take a decade for us to figure out how to truly utilize the wealth of information trapped inside these specimens,” O’Connor says.

  As they examine specimens, scientists stay alert for the products of clever forgers. One specimen marketed as Burmese amber and then subjected to chemical tests contained what would have been the first turtle in amber. “But it was fake,” Xing says.

  * * *

  Across China at NIGPAS, 2,100 kilometers away inside Nanjing’s walled historic center, Wang pours tea. Then he starts to pull out bags of labeled insects in amber. Rare vertebrates may be the charismatic megafau
na of Burmese amber, but invertebrates rule in numbers and diversity. Wang, a paleoentomologist, has amassed a 30,000-piece collection of plants and insects in Burmese amber, many bought here with funds from his institution. He still hasn’t studied it all. “Eventually, we think maybe four thousand or five thousand species can be found,” he says.

  His lab employs an array of high-tech imaging systems to peer into specimens without destroying them. In one room, a laser confocal microscope causes delicate structures—​like the multifaceted eyes of a fly, now splashed from the scope onto an adjacent monitor—​to fluoresce. In another room, a computerized tomography (CT) scanner peers inside fossils to make 3-D models of internal structure.

  By applying those techniques, Wang, like his rivals, has unearthed enough 99-million-year-old evolutionary gambits to fill a nature documentary. Take the lacewings, an insect group that today preys on ants and aphids. In one large glob of amber, the extended wing of a butterflylike lacewing shows a decoy eyespot that may have helped misdirect predators. In another, a lacewing larva looks for all the world like a liverwort plant. Still other lacewings have forest floor debris glued onto their backs, a camouflage strategy many modern insects still use.

  “It’s a pity that most of them became extinct,” Wang says, “but we are lucky we found some hidden stories about them.”

  Some groups have no direct descendants, such as the Haidomyrmecines, nicknamed “hell ants.” They evolved near the base of the ant family tree and sported sharp, sickle-shaped tusks that may have slammed upward to impale other insects. Some, the “unicorn” ants, also had a long top horn, probably used to pin prey in place. “These are like the tyrannosaurs of the ant world,” Grimaldi says, “that you would never know existed if you studied modern living fauna.”