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Maryland ’s new law provides a model for others

Almost 90 years after a Chinese bridge builder discovered a remarkably complete human skull and hid it in a well, Chinese scientists are now introducing it as "Dragon Man," the newest member of the human family, who lived more than 146,000 years ago. In three papers in the year-old journal The Innovation, paleontologist Qiang Ji of Hebei GEO University and his team describe the skull and argue it represents a new species that is a sister group to Homo sapiens, even closer kin to us than were the Neanderthals. Other researchers question that idea. But they suspect the large skull, which the team calls H. longi (long means dragon in Mandarin), has an equally exciting identity: They think it may be the long-sought skull of a Denisovan, an elusive human relative from Asia known chiefly from DNA.

On 10 May, evolutionary biologist Ken Thompson of the University of British Columbia, Vancouver, published a "technical comment" via Dropbox that reads like a frontal attack on his own first paper, published in 2014 in Biodiversity and Conservation. Thompson was the first author of the study, which pitted traditional techniques for identifying plant species against DNA barcoding. But his comment identified what he said were serious issues in data provided by his co-author and supervisor at the time, Steven Newmaster, a prominent lab leader at the University of Guelph. Thompson decided to go public with his suspicions after both the university and the journal declined to investigate them.

A team of prominent scientists has doubled down on its controversial hypothesis that genetic bits of the pandemic coronavirus can integrate into our chromosomes and stick around long after the infection is over. If they are right—skeptics have argued that their results are likely lab artifacts—the insertions could explain the rare finding that people can recover from COVID-19 but then test positive for SARS-CoV-2 again months later. The team, however, doesn9t yet have direct evidence of the integrations in infected people or any data indicating such events harm a person9s health. The team triggered a Twitter storm in December 2020 when it first posted a preprint that reported evidence for this phenomenon. Now, the researchers have a peer-reviewed publication that addresses some of the earlier criticisms, though the hypothesis remains far from proved in the eyes of leading scientists who study this type of integration.

For decades researchers have wondered about the time when modern humans first ventured into the heart of Neanderthal territory in Europe. Now, two new studies of ancient genomes offer a glimpse into the identities of those first moderns to set foot in Europe and their relationships to the last Neanderthals. One study, in Bulgaria9s Bacho Kiro cave, found that modern humans dated to about 45,000 years ago had interbred with our extinct cousins as recently as six generations, or 160 to 180 years, previously. But another study, of a dark-skinned, dark-haired, brown-eyed woman who may be the oldest known modern human in Europe, found that her ancestors had no recent contact with Neanderthals.

On 19 December 2020, the U.K. government announced that scientists had discovered a new variant of SARS-CoV-2 that appears to be spreading more rapidly and implemented stricter lockdown measures in London and southeast England to contain it. The lineage has apparently acquired 17 mutations that lead to amino acid changes in its proteins all at once, a feat never seen before in SARS-CoV-2. As this issue of Science went to press, scientists were still grappling to understand whether the variant really spreads faster, and if so, how. But its emergence drives home the notion that viral evolution could yet result in nasty surprises—just as the first effective vaccines are being rolled out.

Richard Charles “Dick” Lewontin died at age 92 on 4 July, 3 days after Mary Jane, his wife of 73 years. Arguably the most influential population geneticist of the second half of the 20th century, Lewontin laid the theoretical and experimental foundations of modern evolutionary genetics. He was also a prominent social critic and philosopher of science. Born 29 March 1929 in New York City, Lewontin earned his bachelor's degree in biology from Harvard University in 1951. He then joined Theodosius Dobzhansky's genetics and evolutionary biology lab at Columbia University, completing his MS in mathematical statistics in 1952 and his PhD in zoology in 1954. In the years that followed, he held positions at North Carolina State University in Raleigh, the University of Rochester in New York, the University of Chicago, and, from 1973 until his retirement in 1999, Harvard. Throughout his academic career, Lewontin pursued what he called the central “problematic” of population genetics: describing patterns of genetic variation in natural populations and understanding the evolutionary forces that shape them. Because of the dearth of genetic markers, population genetics in the 1950s was strong on theory but weak on data. Then in 1966 came Lewontin and biochemist John Lee “Jack” Hubby with protein gel electrophoresis. This simple technique—detecting allelic differences in proteins that change their electrophoretic mobility—permitted the collection of protein polymorphism data in any species. On finding unexpectedly large amounts of genetic variation in populations, Lewontin and Hubby suggested that much of it might be selectively neutral. In biologist Motoo Kimura's hands, this idea evolved into the neutral theory of molecular evolution, which became the dominant paradigm in population genetics for decades to come. The unexpectedly similar levels of diversity across species revealed by these studies—the “Lewontin paradox”—remains a puzzle still. In 1983, a graduate student in his lab, Martin Kreitman, completed Lewontin's 30-year quest to quantify genetic variation, with the first study of DNA sequence variation in natural populations. Lewontin does not appear as an author on that paper; he refused to list himself as such unless he had contributed substantially to the research. Lewontin's theoretical work complemented his empirical work. He introduced game theory to population biology in 1961 and pioneered computer simulation in the field. With Ken-ichi Kojima, Lewontin coined the term “linkage disequilibrium” to describe the correlation among alleles at multiple loci, an idea central to both modern genetic mapping studies and population genomics. With Jesse Krakauer, Lewontin devised an early statistical test to distinguish between selective and neutral evolution, noting that demographic factors such as bottlenecks affect variation throughout the genome, whereas selection affects only targeted loci. The test had problems, but it underpins modern approaches to genome evolution. Perennially interested in the interaction between the organism and its environment, Lewontin also pioneered niche construction theory. Lewontin worked primarily on Drosophila flies but also coauthored important papers on mice and crickets. In 1972, he took on humans, using relatively crude data derived from serology and allozymes to map genetic variation. His finding was important and counterintuitive: 85% of all human genetic variation can be found within a single population, with only 7% segregating among continental groupings (or “races”). In other words, genetic variation shows remarkable uniformity across the human species. Subsequent studies confirmed these results. Fifteen years later, geneticist Rebecca Cann provided context: Our species is young and only recently ventured out of Africa, meaning that all human populations are closely related. A brilliant and unsparing critic, Lewontin found much to object to in applications of biological determinism to humans. Famously, he and Stephen Jay Gould savaged their Harvard colleague, biologist E. O. Wilson, after Wilson incorporated humans into Sociobiology , his 1975 survey of the adaptive basis of animal behavior. For Lewontin, the assertions of Wilson and others were naive and dangerous oversimplifications. With Gould, Lewontin went on to write an eloquent reminder of the pitfalls of one-dimensional adaptationist interpretation. Their wildly influential essay on the spandrels of San Marco is an appeal for pluralistic thinking. Lewontin wrote extensively (with crystal clarity) for the public both in his books and as a regular contributor to the New York Review of Books . Lewontin, a Marxist who resigned from the National Academy of Sciences to protest its involvement in military research, has been accused of tainting his science with his politics. If anything, though, the “dialectical” approaches that he championed allowed him to remain open-minded yet rigorous when thinking about complex biological patterns. He was dogmatically nondogmatic. His Marxism was arguably a key component of his scientific success. At Harvard, he designed his own research space, assigning the desirable corner office to the Drosophila “kitchen,” where fly food was prepared. The worst job, Lewontin insisted, should be done in the nicest part of the lab. The lab's centerpiece was an enormous table for meetings, rather than the wet lab. Science, Lewontin believed, was forged through discussion. At that table, Lewontin—animated, hands waving, spectacles awry—steered conversations that rampaged across disciplines spanning science, philosophy, politics, history, and sociology. Lewontin's legacy extends far beyond that table. He directly trained generations of scientists, including both of us, and inspired countless more. Despite his disdain for scientific celebrity, he received many awards, including the 2015 Crafoord Prize (shared with theoretical geneticist Tomoko Ohta). He also contributed to unexpected fields, collaborating in the 1950s, for example, with architect Buckminster Fuller to design geodesic domes. However, Lewontin was much more than just the sum of his intellectual contributions; he was a loyal mentor and a beloved friend.

In a world starved for data to clarify the origin of COVID-19, a study claiming to have unearthed early sequences of SARS-CoV-2 that were deliberately hidden was bound to ignite a sizzling debate. Last week, a preprint by evolutionary biologist Jesse Bloom of the Fred Hutchinson Cancer Research Center asserted that Chinese researchers sampled viruses from some of the first COVID-19 patients in Wuhan, China, posted the viral sequences to a National Institutes of Health database, and then later had the genetic information removed to "obscure their existence." Other researchers note the Chinese team published the mutations they found in a scientific journal and that, as one said, it9s "farcical" to assert that they were attempting to hide anything. The sequences themselves do little to clarify the origin questions, but they have fueled suspicions of people who want to see a more open and rigorous probe of the possibility that the virus spilled over from a lab in Wuhan that studies coronaviruses.

Human Evolution Charles Darwin's The Descent of Man was published in 1871. Ever since, it has been the foundation stone of human evolutionary studies. Richerson et al. reviewed how modern studies of human biological and cultural evolution reflect the ideas in Darwin's work. They emphasize how cooperation, social learning, and cumulative culture in the ancestors of modern humans were key to our evolution and were enhanced during the environmental upheavals of the Pleistocene. The evolutionary perspective has come to permeate not just human biology but also the social sciences, vindicating Darwin's insights. Science , aba3776, this issue p. [eaba3776][1] [1]: /lookup/doi/10.1126/science.aba3776

Paleontology Extinct species had complex behaviors, just like modern species, but fossils generally reveal little of these details. New approaches that allow for the study of structures that relate directly to behavior are greatly improving our understanding of the lifestyles of extinct animals (see the Perspective by Witmer). Hanson et al. looked at three-dimensional scans of archosauromorph inner ears and found clear patterns relating these bones to complex movement, including flight. Choiniere et al. looked at inner ears and scleral eye rings and found a clear emergence of patterns relating to nocturnality in early theropod evolution. Together, these papers reveal behavioral complexity and evolutionary patterns in these groups. Science , this issue p. [601][1], p. [610][2]; see also p. [575][3] [1]: /lookup/doi/10.1126/science.abb4305 [2]: /lookup/doi/10.1126/science.abe7941 [3]: /lookup/doi/10.1126/science.abi5697

At some point early in the pandemic, one of the 30,000 letters in the genome of the new coronavirus changed from an A to a G. Today, that mutation has spread around the world; it is found in the vast majority of newly sequenced viruses and has become the center of a burning scientific question: Has the mutation become so common because it helps the virus spread faster? Epidemiology and studies in cell cultures and animals can provide clues, but the question has proved surprisingly hard to answer. Meanwhile, some researchers have noted that the virus does not appear to evolve much at all, despite having infected more than 11 million people. That raises an intriguing possibility: that SARS-CoV-2 was already well adapted to humans when it burst onto the world stage at the end of 2019, having quietly honed its ability to infect people beforehand.

Born in 1881 on a farm in Pennsylvania, Alice C. Evans dedicated her life to studying bacteria in dairy products. Early in her career, Alice became convinced that most bacteria display multicellular behavior as part of their life cycles. At the time, the morphological changes observed in bacterial life cycles created confusion among scientists. In 1928, as the first female president of the American Society for Microbiology, Alice wrote to the scientific community: “When one-celled organisms grow in masses, … individual cells influence and protect one another.” She continued, “Bacteriologists need not feel chagrinned … to admit that… forms they have considered as different genera are but stages in the life cycle of one species” (1). Nearly 100 years later, on page 71 of this issue, Qin et al. (2) make a substantial leap forward in deciphering cell dynamics in biofilms—groups of microorganisms that adhere to a surface, and each other, by excreting matrix components.