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The story of how humans evolved is a long and winding one — and it grows more complicated with each passing year.
Discoveries in the past two decades have added new branches to the human family tree, including species such as the hobbit-like Homo floresiensis and the powerfully built Homo naledi.
A pinkie bone recovered from Denisova Cave in Siberia’s Altai Mountains in 2010 also led to the idea of a distinct ancient human population, dubbed the Denisovans, that some people share ancestry with today.
Now, researchers are trying to solve the puzzle presented by a collection of humanlike fossils that have defied explanation for decades.
We are family
Digitally reconstructed craniums depict fossilized remains found at Xujiayao (left) and Xuchang. The large, low and wide shape is distinct from the skulls of other known hominin species. – Courtesy Xiujie Wu
Skull fragments, teeth and jaws found at different sites in China have led some researchers to believe they have found the remains of a previously unknown ancient human relative.
The scientists are proposing that the human ancestor, which had an extremely large brain bigger than that of modern humans, be called Homo juluensis.
The designation of a newly identified species seems controversial to some experts.
But researchers Christopher Bae, a professor at the University of Hawaii at Manoa, and his colleague Wu Xiujie, a senior professor from Beijing’s Institute of Vertebrate Paleontology and Paleoanthropology, believe the species may also include the elusive Denisovans — even though a skull specimen traced to the cave-dwelling people has yet to be found.
Across the universe
Astronomers have been trying to determine what causes mysterious fast radio bursts from space since their discovery in 2007. The flashes release more energy in milliseconds than the sun does in a day.
Now, the Canadian Hydrogen Intensity Mapping Experiment radio telescope has helped researchers pin down the sources of two recently described bursts.
Scientists traced one to the turbulent, magnetically active region around a rapidly spinning star called a magnetar. The other pulsated from the outskirts of a distant old, dead galaxy no longer producing stars, according to a new study.
The wildly different origin points have led astronomers to believe the flashes can occur in diverse environments. The revelation could help unlock what causes the phenomenon.
Wild kingdom
Native to Australia, brush-tailed bettongs are marsupials resembling tiny kangaroos. – WWF-Aus/think Mammoth
The brush-tailed bettong could be mistaken for a miniature kangaroo based on its appearance and the pouch that holds its young.
But the tiny marsupial has a not so warm and fuzzy side: It will eject the baby, called a joey, in its pouch and bounce away when threatened by predators. The brutal strategy is necessary for survival in a species that has seen its population decline by 90% — and even disappear for a time from South Australia’s Yorke Peninsula.
Conservation efforts are returning the brush-tailed bettong to its native land, where it plays a key ecological role. As the marsupials dig for their primary diet of underground fungi, they aerate the soil and encourage the growth of plants that other animals rely on.
Look up
A Ring doorbell camera captured the moment a meteorite slammed into the front walkway of a home on Canada’s Prince Edward Island — where local professor Joe Velaidum had been standing just moments before.
Scientists have now confirmed the specimen, named Charlottetown after the nearby capital city, is indeed a space rock that fell to Earth in July.
While videos have documented meteorite strikes before, it’s the first time one has been seen at such close range, complete with sound.
The space rock likely spent millions of years hurtling around our solar system before winding up in its new home: the University of Alberta Meteorite Collection.
Other worlds
Thousands of mounds cover the lowlands of Mars, and they may hold the key to understanding the red planet’s past.
The towering features are similar to the buttes and mesas of Monument Valley along the Arizona-Utah border. Ancient water flows that existed 4 billion to 3.8 billion years ago likely eroded and sculpted the formations, according to a new analysis of orbital images.
The mounds include layers of minerals that can reveal the history of water on Mars, and they may be investigated by the European Space Agency’s ExoMars Rosalind Franklin rover, expected to launch in 2028.
The formations have also provided insight into one of the biggest mysteries on Mars — why the planet has a marked boundary between the soaring highlands of its southern hemisphere and shallow plains in the northern hemisphere.
Curiosities
Expand your knowledge with these intriguing reads:
— Molten metals in Earth’s core generate a constantly moving magnetic field, which means the magnetic north pole isn’t fixed. It’s now closer to Siberia than it was five years ago — and it’s continuing to drift toward Russia.
— Camera traps helped scientists spot rare species, including the sun bear and the first recorded sighting in Cambodia of a critically endangered deer species called the large-antlered muntjac, in a virtually unexplored part of the Southeast Asian nation.
— Archaeologists in Denmark unearthed hundreds of disks marked with carvings of the sun. The researchers believe Stone Age farmers buried the “sun stones” in response to a devastating volcanic eruption nearly 5,000 years ago.
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