Supporters of these types of experiments — called human challenge trials or controlled human infection models — argue that they are the quickest and cheapest way to develop new vaccines, test medicines and study the basic progression of some of humanity’s most enduring infectious foes, as well as some new ones. A major benefit of human challenge trials is that, because they deliberately cause infection, vaccines can be verified using far fewer people — in the Zika case, perhaps just 200, says Diamond, who cowrote an update on Zika vaccine development in the 2019 Annual Review of Medicine. In November 2018, the Wellcome Trust invited proposals for further human challenge trials to run against more diseases endemic in low- and middle-income countries.

Sandra Martelli, a researcher in biology and anatomy at the University College London, has been working with computer models to try to reconstruct the most likely configuration of the Neanderthal vocal tract. Martelli and colleagues took CT scans of modern human heads, including the hyoid, and mapped those on to CT scans of Neanderthal skulls to see where the Neanderthal hyoid (as represented by Kebara 1) likely sat. Martelli and her colleagues found that the most likely position for the Neanderthal hyoid was slightly forward from where the modern human hyoid bone sits, with no room for an apelike air sac.

And from the discovery of a curious spiky growth on the back of many people’s skulls to the realisation that our jaws are getting smaller, to the enigmatic finding that German youths currently have narrower elbows than ever before, it’s clear that modern life is having an impact on our bones. The man’s skull, arm bones, collarbones, and the bones of his lower legs suggested that he had been immensely strong and unusually tall. Shahar thinks the spikes form because the hunched posture creates extra pressure on the place where the neck muscles attach to the skull – and the body responds by laying down fresh layers of bone.

Close to 100 million tons of nitrogen added to the world’s crop fields are lost to the environment every year, either as gas emissions or as runoff.While nitrogen fertilizer deserves considerable credit for driving a century-long global increase in crop yields, it’s also nasty stuff. And, as the hypoxic zone indicates, nitrogen fertilizer is a huge environmental hazard: Close to 100 million tons of nitrogen added to the world’s crop fields are lost to the environment every year, either as gas emissions or as runoff. Pivot Bio, a Silicon Valley startup, believes it can convince farmers to swap out nitrogen fertilizer in favor of specially-fermented soil bacteria that can fuel crop growth organically, without the waste and ecological hazard of traditional methods.

Since we do not notice our constant saccades, this suggests that the brain specifically suppresses the signals that reach our retina while a saccadic eye movement is in process. In experiments with macaques that were trained to make predictable saccades, brain cells that receive signals from one particular spot in the retina switched from responding to things currently in view there to things that would show up only after the saccade. Wurtz and others believe that this kind of signal nudges brain cells to start responding to things that their part of the retina will see only after the saccade.

He and colleagues stated that as recently as 5,800 years ago (a mere heartbeat in evolutionary time), one genetic variant that was linked to the brain, among other things, had emerged and swept through populations as a result of evolution by natural selection. Lahn seemed to imply that the brains of different population groups might have evolved in different directions for the past five millennia, and that the groups with this special genetic difference may in consequence have become more sophisticated than others. Soon after the papers were published, the controversial Canadian psychologist John Philippe Rushton ran IQ tests on hundreds of people to see if the gene variants really did make a difference to intelligence or to brain size in those who possessed them.

To find the second planet and provide even further confirmation for the first one, a team led by Sebastiaan Haffert at Leiden University in the Netherlands used MUSE, a new instrument on the VLT, to search for emission from hydrogen. The first planet, dubbed PDS 70b, prowls right outside the inner edge of this gap in the disk. “PDS 70 is really becoming a benchmark system,” said Julien Girard, an astronomer at the Space Telescope Science Institute who collaborated on the discoveries of both the second planet and the possible moon-forming disk.

The American Academy of Dermatology also recommends it for everyone: “Sunscreen use can help prevent skin cancer by protecting you from the sun’s harmful ultraviolet rays. Given the sun’s probable role in most skin cancers, though, it’s surprising that there isn’t stronger evidence that sunscreen prevents all forms of the disease. The analysis found strong evidence that sunscreen prevented squamous cell, but not basal cell carcinomas, most likely because those cancers develop too slowly for studies to detect a trend, said lead author Reid Waldman, a dermatology resident at the University of Connecticut.

The 40,000-year-old head of a Pleistocene wolf.Image: Albert Protopopov
A well-preserved head belonging to an ancient species of Pleistocene wolf has been pulled from the permafrost of northeastern Siberia. A CT scan of the wolf skull.Image: Albert Protopopov, Naoki Suzuki
“It is a very exciting discovery, and as the remains seem well-preserved it will hopefully be possible to obtain high-quality DNA to examine the animal’s genome, and compare both its genomic profile and anatomy with that of modern wolves from Siberia and beyond,” said Astrid Vik Stronen, an ecologist from the Department of Biotechnology and Life Sciences at Insubria University in Italy who’s also not involved with the new research, in an email to Gizmodo. This is truly a remarkable discovery, and as both Meachen and Stronen pointed out, the best is yet to come in terms of what we’ll learn from this incredibly well-preserved wolf head.

If a long human life is about 80 years, Wing says, then people can count 80, 160, and 240 years, meaning the sequoia grew and thrived over the course of approximately three human lifespans—but during a time when our own ancestors resembled gibbon-like apes. In everything—from the rings of an ancient tree to the very bones in your body—time is part of life. “Time is so vast,” Wing says, “that this giant slab of a tree is just scratching the surface.”