Ewen Callaway News 27 Jul 2022 – Dual action of ketamine confines addiction liabilityExperiments in mice show that although ketamine has positive reinforcement properties, which are driven by its action on the dopamine system, it does not induce the synaptic plasticity that is typically observed with addiction.
The cover shows an artistic impression of marine life in Indonesia’s coral reefs. The question of whether there are limits to biodiversity in the seas is typically addressed by examining the fossil record. In this week’s issue, Pedro Cermeño and his colleagues present a model that combines the fossil record with plate tectonics and Earth’s environmental conditions to offer insight into regional diversification of marine invertebrates. The researchers used the model to examine how biodiversity recovered after mass extinctions during the Phanerozoic eon, covering
some 500 million years of Earth’s history. They found that throughout the Phanerozoic, less than 2% of area of the globe covered by water showed signs of diversity levels reaching saturation. The team also note that as Pangaea broke up into continents, the stability of Earth’s environmental conditions allowed the development of diversity hotspots that helped to drive an increase in biodiversity in the late Mesozoic and Cenozoic eras.
Although the domestic dog can trace its origins to the grey wolf (Canis lupus), exactly when, where and how domestication happened has remained a source of debate. In this week’s issue, Anders Bergström, Pontus Skoglund and their colleagues, take a step towards resolving this question. The researchers analysed the genomes of 72 ancient wolves from across Europe, Siberia and North America, and spanning the past 100,000 years. They found that dogs are most closely related to ancient wolves from eastern Eurasia but that dogs in the Near East and Africa derive
up to half their ancestry from a distinct population related to modern southwest Eurasian wolves. Although none of the genomes analysed was a direct match for either dog ancestry, the researchers say that it has narrowed down where next to look for the ancestors of domestic dogs.
The cover shows an artistic representation of various cancer cells. The large-scale gains, losses and rearrangements of DNA seen in chromosomal instability are a typical feature of cancer — but there is no comprehensive framework to decode the causes of this genomic variability and their possible links to disease. In this week’s issue, Florian Markowetz, Geoff Macintyre and their colleagues present such a framework with a compendium of 17 signatures of chromosomal instability that can be used to predict how tumours might respond to drugs and that help to identify future therapeutic targets. The team created the compendium by examining 7,880 tumours representing 33 types of cancer. In a separate paper, Nischalan Pillay and colleagues examined 9,873 cancers to generate
To study inequality is to confront a world of contrasts: excessive wealth next to palpable poverty; sickness abutting health. The COVID pandemic has exposed and worsened many such disparities. This week, Nature presents a special collection of articles focusing on the researchers trying to quantify and reduce inequality. Whether they are measuring the effects of the pandemic or testing interventions to lift people out of poverty, the message is simple: gathering the right information will help to mitigate the harm caused by inequality.
The cover image shows plants growing at altitude on Altar Volcano in Chimborazo, Ecuador. Extreme altitudes pose challenges for most forms of life, and flowering plants are no exception. But flowering plants have been found growing as high as 6,400 metres above sea level. In this week’s issue, Michael Holdsworth and his colleagues reveal a molecular mechanism that helps plants to adapt to the extremes of altitude. The researchers studied a range of plants, representing four diverse clades of flowering plants — thale cress (Arabidopsis thaliana), tomato, poppy and the grass
Brachypodium distachyon. They found that plants use genetic adaptations to adjust their sensitivity to atmospheric oxygen, whose partial pressure decreases with altitude. By decoding the ambient oxygen level, the plants are able to sense the altitude at which they grow and optimize internal biochemical processes.
When Charles Darwin’s cousin, Francis Galton, coined the word eugenics in 1883, he called it the study of the conditions under which “men of a high type are produced”. This gross idea led to the gates of Auschwitz, reminds broadcaster Adam Rutherford (an alumnus of the Galton Laboratory, former name of University College London’s human‑genetics centre). It hasn’t gone away, he explains in his timely salvo on the politics and history of notions that dog genetics, events up to and after the ‘CRISPR twins’ and the resurgence of white supremacy.
Dark and Magical Places
Christopher Kemp Profile/Wellcome Collection (2022)
“I have no sense of direction,” confesses molecular biologist Christopher Kemp — unlike his wife, “an effortless and intuitive navigator”. Once, in a mirror maze, he was transfixed with alarm, and had to be pulled out by his seven-year-old son. Many others experience similar disorientation, sometimes with disastrous results, as when hikers get lost. Their stories vitalize this compelling study of the brain, memory and navigation, in which one psychologist compares our understanding of parts of the brain with knowledge of black holes.
When the World Runs Dry
Nancy F. Castaldo Algonquin (2022)
Globally, millions of people must walk up to 6 kilometres daily to get clean water, says environmental writer Nancy Castaldo. Moreover, each year, more children die as a result of water contamination than from violence, including war, said the United Nations in 2019. Castaldo’s alarming book discusses many examples of shortages and tainting, ranging from drought in Cape Town, South Africa, to lead pollution in Flint, Michigan. She concludes with realistic steps to reduce domestic consumption and contamination.
Making Numbers Count
Chip Heath and Karla Starr Avid Reader (2022)
Business scholar Chip Heath and science journalist Karla Starr are familiar with the need to “translate numbers into instinctive human experience”, informatively and memorably. Unable to find a book on the subject, they decided to write their own. Their diverse guide bubbles with translated statistics. For example, there are about 400 million civilian-owned firearms in the United States — that translates into one for every adult and child, with around 70 million left over.
Genetically Modified Democracy
Aniket Aga Yale Univ. Press (2021)
India’s 1960s Green Revolution began without much deliberation. The government promoted high-yielding varieties of wheat and rice, and guaranteed purchase prices. This helped “already well-off, landed farmers”, notes environmentalist Aniket Aga, but led to huge debts for the struggling majority. When genetically modified crops reached India in 2002, they cultivated much more scrutiny, involving scientists, seed companies, farmers, consumers and the state. Aga describes the debate, without claiming to provid
The Casarabe people lived in southwest Amazonia around AD 500–1400, but understanding of this culture has been limited because the archaeological remains are covered in dense forest. In this week’s issue, Heiko Prümers and his colleagues reveal the discovery of new Casarabe settlements in the Bolivian Amazon. The researchers used lidar to scan the forest, revealing 2 large settlements (each covering more than 100 hectares) and 24 smaller sites, 15 of which had previously been known to exist.
The cover image shows Cotoca, one of the two large settlements, in which earthen mounds (one more than 20 metres high) and long causeways can clearly be seen. The team suggests that these results are the first evidence of agrarian-based, low-density urbanism in western Amazonia. They conclude that the region was not as sparsely populated in pre-Hispanic times as was previously thought.
With six sets of chromosomes, the hexaploid cultivated oat (Avena sativa L.) has a complex evolutionary history. In this week’s issue, Nick Sirijovski and his colleagues present a high-quality reference genome for A. sativa alongside those for its close relatives the diploid Avena longiglumis and the tetraploid Avena insularis. By examining the three genomes, the researchers were able to trace genomic reorganizations in the crop’s evolution. They were also able to map the genes for important agronomic traits, highlighting gene families linked to human health and nutrition. With health and sustainability high on global agendas, the team hopes this new resource will bolster genomics-assisted breeding and trait studies to address these challenges and more.
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