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A Heliconius butterfly.Credit: Tim Zurowski/Shutterstock

Every butterfly in the United States and Canada — 845 species — has now had its genome sequenced. Some researchers are hailing the study as a landmark in genomics because of the comprehensive survey will allow them to explore big questions in evolution, such as why some branches of the tree of life are so diverse. Although most of the genomes are low-quality ‘drafts’, comprising short stretches of DNA, the data are already hinting at how new species can arise from interbreeding.

Nature | 5 min read

A growing number of research agencies looking to lighten the load of paperwork and reduce bias are turning to a simple solution: pulling winners out of a hat. Typically, funders screen applications to ensure they meet a minimum standard, then select projects at random until all the cash has been allocated. Application forms are shorter, and no time is spent agonizing over the ranking of lots of projects that are all worthy.

Nature | 5 min read

Doctors have placed humans in suspended animation for the first time, as part of a trial to save the lives of people who face imminent death from their injuries. The technique involves replacing all of a person’s blood with ice-cold saline, rapidly cooling them and causing their brain activity to stop — a condition that would normally be used to diagnose someone as being dead. Surgeons then have two hours to do their work before the person is warmed up and their heart restarted. Results from the trial, which is taking place at the University of Maryland Medical Center in Baltimore, have not yet been revealed.

New Scientist | 4 min read

Features & opinion

Comet 2I/Borisov appears as a fuzzy blue dot in a time-lapse sequence from the Hubble Space Telescope, which shows background stars as streaks.NASA/ESA/D. Jewitt (UCLA)/J. DePasquale (STScI)

Researchers grapple with the meaning of Comet 2I/Borisov and 1I/‘Oumuamua — the first objects known to enter our Solar System from interstellar space. ‘Oumuamua whizzed past the Sun in 2017, and left astronomers boggled by its very un-comet-like small size and elongated shape. By contrast, Borisov — which makes its closest approach to the Sun next month — is much more familiar. “It’s been so much fun to see this suddenly crack open and watch a new field develop,” says planetary astronomer Michele Bannister.

Nature | 8 min read

Nearly one in four graduate students who responded to a Nature survey said they would change their supervisor if they could start their programme again. More than 6,300 people worldwide responded to our biennial PhD survey, and many raised the need for more one-to-one support and better career guidance.

Nature | 6 min read

Major victories for open access have led some advocates to conclude that their battle is almost won, writes journalist Richard Poynder. But, he argues, a splintered Internet, tense geopolitics and publishers moving to control data could see barriers re-erected around research papers and make a fair and equitable global system of scholarly communication impossible.

Richard Poynder personal blog | 4 min intro and the full 84-page PDF

Correspondence: your letters to Nature Nature editor’s writing secret Legendary Nature editor-in-chief John Maddox had a tip that helped him write insightful editorials on a host of topics week after week, writes former India correspondent Killugudi Jayaraman: shut the door and allow no phone calls or other interruptions until you’re done. Crowdsourcing Chile’s political future Chileans are demanding change, and “their voices need to be aggregated if they are not to be lost in the din of rallies or fragmented into thousands of tweets”, writes digital transformation researcher César Hidalgo. He points to his experimental platform Chilecracia, which asks people to prioritize policies put forward by experts. Map Canada but keep carbon in the ground There is much to applaud in the EON-ROSE (Earth-system Observing Network-Réseau d’Observation du Système Terrestre) project to understand Canada’s geology and to find geothermal energy, writes economist Talan İşcan. But he urges scientists to reject money from companies that would use the science to develop carbon-based energy and environmentally destructive mining. Correspondence is published every week in Nature. For more info on writing one yourself, please see the guidance on nature.com. (Your feedback on this newsletter is always welcome at briefing@nature.com, but won’t be considered for publication in Nature.)