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Scientists have discovered a ‘lost world’ of early microorganisms that once thrived in the world’s oceans. Eukaryotes (the group that includes amoebae, mushrooms, plants and people) were thought by some to have become abundant only around 800 million years ago. That’s when ancient rocks bear the telltale signs of the organisms’ existence in the form of fat-like molecules called sterols. But it turns out that precursor ‘protosterol’ molecules are present in rocks dating back even further, to 1.6 billion years ago. The now-extinct eukaryotes that produced these protosterols lived in watery environments between 800 million and 1.6 billion years ago, but were replaced by modern sterol-producing eukaryotes by the end of that period.
There’s no evidence that people are not as kind, respectful and trustworthy as they used to be. Decades’ worth of survey results show that people in 60 countries have perceived a general moral decline for at least the past 70 years. But individuals’ evaluation of their contemporaries’ morality has remained largely unchanged. Biased memory could be a factor in maintaining the illusion: negative memories tend to fade faster than positive ones, which might help to explain why people believe that past morality was relatively high.
An artificial intelligence (AI) developed by Google DeepMind created algorithms that can sort data up to three times as fast as can human-generated versions. “We were a bit shocked,” said DeepMind computer scientist Daniel Mankowitz. “We didn’t believe it at first.” The technology is based on AlphaZero, an AI for playing board games including chess and Go. But, instead of applying its combination of deliberation and intuition to choose the next move, it chooses instructions to add to a procedure.
Features & opinion
Scientists were stunned when aerial surveys revealed a tree in the Amazon that is nearly as tall as the Statue of Liberty. It had probably not been seen by anyone before: no people live within 100 kilometres, and even if they had passed by, it would have been impossible for them to see the top through the thick canopy. In this lushly photographed feature, a team of researchers finally reaches the spectacular forest giant. “This discovery, from just a couple of years ago, highlights that we still don’t know everything,” says remote-sensing specialist Jacqueline Rosette.
Environmental scientist Max Liboiron runs a feminist, anti-colonial laboratory. This means that everything the team does — “who we hire, who we collaborate with and how we take out the trash” — is tied to principles of humility, accountability and collectivity. Data are co-analysed with the community in which they were collected, oral histories are cited in publications and samples are returned to the place they were taken from. The first step for other researchers who want to adopt a similar approach, Liboiron says, is to put individualism aside and understand what the community needs. “We don’t go anywhere we are not invited to collect samples or do our science, even if that science will be amazing and useful,” they say.
On World Ocean Day, physicist and oceanographer Helen Czerski argues that we must be wary of efforts to exploit the ocean to help achieve our land-based goals — by sequestering carbon from the atmosphere, for example, or mining minerals from the sea floor. “You can’t ‘just’ fertilise the ocean, or change its alkalinity, or park huge new farms there, or dump billions of tonnes of biomass into the deep sea without affecting the existing ocean physics, chemistry and biology,” she writes. She argues for a view of the ocean as a dynamic, intricately structured engine that can be utilized only with great sensitivity. “You can’t start from the assumption that the ocean isn’t doing anything of value down there already.”
Infographic of the week
In this map of the Tara Pacific expedition, the locations of sampled coral systems are shown as red circles and oceanic sample locations are blue dots). The inset shows an in-depth example: coral sampling locations around Upolu, an island in Samoa, with overlaid temperature as recorded by the inline thermosalinograph. The break in sampling during the return trip across the Atlantic Ocean is due to bad weather. (F. Lombard, G. Bourdin, S. Pesant et al./Sci Data (CC-BY-4.0))
Gathering good biodiversity data can be a mission in itself, especially on marine biodiversity. One dependable source is a schooner called Tara, which celebrates 20 years at sea as a research ship this year. Last week, researchers reported the results of its latest voyage, Tara Pacific, a two-year expedition across the Pacific Ocean, published in a collection of articles in Springer Nature journals.
The research ship has a stirring and unusual back story, notes a Nature editorial. Its original captain was Peter Blake, a much-decorated professional yachtsman. After retirement, Blake became an environmental envoy to the United Nations, but was killed by pirates at the mouth of the Amazon River while on an expedition in 2001. The fashion designer known as Agnès B and her son acquired the boat, determined to continue Blake’s original vision. They established the Tara Ocean Foundation and invited scientists and research funders to join them on various missions.