AMONG THE MOST FAMOUS OF ALL events in evolutionary history (if something that took 30 million years could be called an event) is when a lineage of fish-like animals emerged from the water onto the land, setting the scene for the radiation of amphibians, reptiles, birds and mammals. But over the following 370-odd million years, some of these terrestrial vertebrates performed spectacular U-turns: ichthyosaurs, plesiosaurs, sea turtles, penguins, whales, dolphins, manatees, dugongs, seals, sealions and walruses all returned to the sea. Who could tell from looking at a whale or a dolphin that they are descended from a group of terrestrial mammals that includes hippos and cattle? Or that manatees and dugongs are the closest living relatives of the elephants? The ancestry of seals and sealions – which, together with…

RESEARCHERS HAVE witnessed a new phenomenon in the brain as humans store memories, shedding light on the how the brain coordinates its many regions and billions of neurons. The team recorded participants' brain activity while they performed tasks that required memorising and recalling lists of words or letters. “Broadly, we found that waves tended to move from the back of the brain to the front while patients were putting something into their memory,” says Uma R. Mohan, a postdoctoral researcher at the National Institutes of Health in the US. “When patients were later searching to recall the same information, those waves moved in the opposite direction, from the front towards the back of the brain.” Brain waves are electrical oscillations that represent patterns of neural activity. Travelling waves spread out…

SCIENTISTS PLAN TO BRING ICONIC species back from extinction, which might have environmental benefits. Notably, the woolly mammoth could be a flagship species for conservation, highlighting the plight of endangered animals sharing its habitat. Mammoths reintroduced to the Arctic tundra would also work as ‘ecosystem engineers’, trampling trees and permafrost. This might recreate ice-age grassland, a surface that better reflects sunlight and traps carbon, helping to fight climate change. But is the resurrection of extinct species a reality, or simply sci-fi? How does de-extinction work? There are three methods. First, selective breeding or ‘back crossing’ – mating between members of a living species carrying traits of their ancestors, to increase the frequency of those ancestral traits within a population. That’s how cattle were bred to become ‘tauros’, a species that…

Our experts examine the hottest new research CUTTING EDGE White dwarf stars are formed when all but the most massive stars run out of hydrogen fuel for their nuclear fusion and exit the main sequence. The star swells up as an enormously inflated red giant, puffing off its outer layers into a beautiful nebula of ionised gases. The core is all that remains of the original star and, as it can no longer support fusion, this ‘white dwarf’ slowly cools over billions of years. The majority of white dwarfs are composed of mostly carbon and oxygen, as these are the elements most red giants create towards the end of their lives. If the progenitor star was nearer eight times more massive than our Sun, however, there's an extra final step…

If you were told that the Moon we see in our night sky isn't Earth's only one, you'd probably be a bit surprised. But some people have started to call the strange object that seems to orbit our planet, Earth's ‘second moon’ – and now scientists may have discovered where it came from. In fact, there are many moon-like objects around us in space, but only a handful of the over 200,000 ‘near-Earth asteroids’ (NEAs) have similar orbits to Earth. One of these, named 469219 Kamo‘oalewa, orbits the Sun, but moves in sync with our orbit so appears to orbit the Earth. This makes it our ‘quasi-moon’ or, to some, an ‘Apollo asteroid.’ Potentially as big as the Statue of Liberty, Kamo‘oalewa is between 40 and 100m (131–328 feet) across…

Tigers There are currently 3,900 wild tigers estimated to be prowling the Earth. That’s 97 per cent fewer than existed a century ago. Of the nine tiger subspecies, three are extinct – the Caspian, Javanese and Balinese – and the South China tiger is known to be ‘functionally extinct’ with only a handful of individuals left in the wild, while the other five subspecies are endangered. So, in a bid to bring this beguiling big cat back from the brink, the governments of the world’s 13 tiger range countries made a plan. Through working with conservation experts, scientists, rangers and communities, they have pledged to double the tiger population by 2022 – the next Year of the Tiger in the Asian lunar calendar. These majestic creatures are apex predators and…

JUST STEPPED OUT FOR A WALK Astronauts train for many years for the chance to go to space, with no guarantee of actually flying, so being given a place on a mission to live on the International Space Station (ISS) for a few months is a dream come true. But some astronauts get to do even more – they wriggle into a spacesuit and go outside on an extravehicular activity (EVA), or spacewalk. This image, taken on 23 May 2017 during the 201st spacewalk of the ISS program, shows NASA astronaut Jack Fischer waving at his colleagues watching from inside the space station as he worked outside the US Destiny laboratory. Fischer was attaching antennae to the exterior of the ISS during an unplanned EVA to repair and replace a…

BULLETIN For the first time, astronomers have observed the ‘plunge region’ surrounding a black hole, where orbiting material can no longer resist gravity's pull and plummets inward. The region is predicted by Einstein's theories, but has eluded the gaze of scientists until now. Most black holes pull gas from surrounding stars, surrounding themselves with an accretion disc. According to Einstein's theories of gravity, there is a point at which any particle straying too close to a black hole would no longer be able to continue in a circular path. Instead, it plunges rapidly inwards, towards the event horizon at close to the speed of light. While matter in this plunge region is doomed to fall inwards, light is still able to escape, meaning it should be possible to observe. Accretion…

WIDEST REACH Mosquitos Mosquitos are responsible for almost half a million human deaths per year These insects pose an unusual threat to mankind for a creature that is, on average, only five millimetres (0.2 inches) long. Around the world, mosquitos are carriers of a staggering variety of diseases. There are about 3,500 known species of mosquito in existence, and in most cases the females are the only ones to feed on the blood of live hosts. They possess a minute but sharp proboscis, which can pierce even the tough skin of an elephant. Mosquitos preserved in amber dating back to the Cretaceous period have been discovered, but it’s thought these tiny menaces have been around for more than 200 million years, since they first diverged from other insects. Malaria accounts…

FOR a long time, it looked as if the Soviet Union would beat the US towards the ultimate victory in the space race. But when the Soviet Union’s N1-L3 test vehicle toppled backwards in flames onto its launch pad, it become clear that the US would make it to the moon first. On 21 July 1969, just five days after taking off from Cape Canaveral in Florida, the Apollo 11 crew touched down on the moon. Following Neil Armstrong onto the lunar plain of the “Sea of Tranquility” was Buzz Aldrin, the second man to walk on the moon. Completing the mission’s crew of three was Michael Collins, who remained alone circling the moon in the orbiter that had dispatched the landing module, codenamed Eagle. But how did the crew…

There seems to be a lot of overlap between supposedly different types of anomalous phenomena. For example, starting in the mid-1960s, and continuing until about 1977, the Warminster area of Wiltshire generated numerous reports of UFO sightings, although claims about strange phenomena thereabouts weren’t confined to aerial manifestations.1 There were, for instance, reports about people hearing mysterious footsteps, and of vehicles colliding with human-like figures, but with no casualties being found. However, the Warminster case is controversial, with some commentators suggesting that prosaic factors, such as the misinterpretation of ordinary aerial objects and sensationalist news reporting can explain what allegedly occurred (not to mention hoaxing; see FT331:40-47). But if a substantial number of the reports were true, the locality may have been, at least temporarily, a hot spot for weird…