Hello Nature readers,
Today we learn not to judge a man o’ war by its cover, consider whether mega-funders can save a highly-cited health database hit by US cuts and discover what brain science has to say about eureka moments.

The man o’ war is at least four species

With its gas-filled float and muscular crest, Physalia — called the Portuguese man o’ war or bluebottle — sails the open seas, leading some to assume that they’re part of one big, well-mixed population. Not so, finds a study that sequenced the whole genomes of 151 animals gathered from around the world. There are at least four separate species, including a newly named one, Physalia minuta. “We were shocked, because we assumed they were all the same,” said marine ecologist and co-author Kylie Pitt. “But the genetic data clearly show they’re not only different, they’re not even interbreeding.”

Can a crucial health data set be saved?

In February, the US government cut all funding for the Demographic and Health Surveys (DHS) programme, which collects and publishes data on health, nutrition and gender equality in more than 90 countries. The cuts leave the future of the DHS’s highly-cited database hanging in the balance. Now, the UN Statistical Commission, the world’s body that sets standards for statistics, has established a taskforce to assess how access to the database can continue. Funding from organizations such as the World Bank and the Gates Foundation could come to the rescue. The taskforce must also grapple with who owns the data, which will dictate how external funders can get involved.

Mountain animals make bad smellers

Animals that live in the mountains, such as llamas and some goats, have a worse sense of smell than those that live nearer to sea level. Researchers found that high-altitude animals don’t have many genes that encode nasal receptors, and the higher they live, the fewer there are. These animals also have a smaller olfactory bulb — the brain region responsible for picking up scents — than their low-elevation counterparts. The outlier is humans — the team found that people who live in Tibet have a similar number of smell-related genes as do people who live in a nearby, much lower, region in China.

How to catch lightning in a bottle

Scientists are using the tools of neuroscience to reveal which regions of the brain are active during moments of insight, and how they interact when ‘eureka!’ strikes. They’ve refined the puzzles they use to trigger insight and the measurements they take, in an attempt to turn a self-reported, subjective experience into something that can be documented and rigorously studied. This foundational work has led to new questions, including why some people are more insightful than others, what mental states could encourage insight and how insight might boost memory.

A model organism in the making

With legs, a central brain and a peripheral nervous system, tardigrades sit in a sweet spot for scientists: simple enough to study easily and intricate enough for it to be worth doing so. That could make them good ‘model organisms’ — a species used to extensively probe into one aspect of biology — for studying how neural circuits work, say some neuroscientists. The microscopic animals aren’t ideal candidates, not least because researchers aren’t sure what types of neuron the creatures have, or how many. Nonetheless, tardigrade enthusiasts are ready to fight their corner. “I have faith in the tardigrade community,” says organismal biologist Jasmine Nirody. “We’re determined.”

What we lose when we use AI

In response to an article published in March about using artificial intelligence (AI) to streamline peer review, researchers Carl Bergstrom and Joe Bak-Coleman question whether there are areas of scientific work where AI should not go. “Reading the literature, drafting manuscripts and engaging in peer review, for example … rely on something even more precious than our time: namely, our capacity for scientific decision-making,” write the authors, who study how digital information technologies affect society. “It is worth considering what we lose when we cede that — and our agency — to machines.”