Hundreds of fossils uncovered in southern China's province of Yunnan reveal that at least some of the life-forms scientists had thought arose in the Cambrian period were alive and thriving millions of years earlier, in an era known as the Ediacaran period.
Four protrusions appear to be arranged in pairs, each consisting of two connected branches surrounding a central depression. We really don't understand what any of these features represent anatomically.
Such sex 'distorters' have been discovered - and studied in great depth - in laboratory animals such as mice and flies, in which their effects can be detected through selective breeding. 'If you look, more often than not, you find them,' says Nitin Phadnis, an evolutionary geneticist at the University of Utah in Salt Lake City, who co-led the study.
Human breasts sit at an elevated temperature, protecting a newborn from hypothermia. What's more, the size and shape of the breast allows for broad contact surface - enhancing the heat transfer from mother to child. This could improve a newborn's chances of survival and provide an evolutionarily grounded explanation for the development of external breasts in humans.
The mirror spider can rapidly shift a patchwork of minuscule reflective plates underneath its abdomen's outer surface, altering the pattern of mirrorlike flashes. This uncommon display comes from common building blocks: Similar tilelike arrangements of plates and soft joints appear throughout the tree of life, from turtle shells to tropical fruit peels. Researchers have now compiled 100 examples of this pattern across animals, plants, microbes and viruses, which they describe in PNAS Nexus.
Wooden objects carrying the marks of carving and use could be the oldest wooden tools ever found. Researchers dated the artefacts, found in what is now Greece, to 430,000 years ago - and suggest they might have been made by early Neanderthals or their ancestors, Homo heidelbergensis. A separate study describes 480,000-old flint-knapping tools made from antler and elephant bone, from what is now the United Kingdom.
The study's authors researched 96 peer-reviewed studies documenting SSB to compile one of the most comprehensive datasets for primates to date. The study found that SSB are a "persistent and integral component of primate social [practices]." In fact, the prevalence of SSB across a variety of closely related primate species - and over several lines of descendants - "indicates a deep evolutionary root or multiple independent evolutionary origins," the study's authors wrote.
New research published today in Nature dates the boneschipped out from a cave called Grotte a Hominides and nearby it over decadesto about 773,000 years ago, during the era of the last common ancestor of Homo sapiens, Homo neanderthalensis and Denisovans (a group of humans that ranged across Asia and that does not have an agreed-upon species name). We can say that the shared ancestry between these three species is perhaps in Grotte a Hominides in Casablanca, says study co-author Abderrahim Mohib, a prehistorian at the National Institute of Archaeology and Heritage Sciences in Rabat, Morocco.
The lava heron also has a much thicker bill than other closely related herons - an adaptation linked to feeding among sharp volcanic rocks and hard-shelled prey. "What we learned was something that hadn't been reported before," Mendales said. The discovery underscores how much remains unknown, even in iconic places like the Galápagos, said John Dumbacher, the Academy's curator of birds and mammals and Mendales' thesis adviser.
Which animals came first? For more than a century, most evidence suggested that sponges, immobile filter-feeders that lack muscles, neurons and other specialized tissues, were the first animal lineages to emerge. Then, in 2008, a genomic study pointed to a head-scratching rival: dazzling, translucent predators called comb jellies, or ctenophores, with nerves, muscles and other sophisticated features. That single study ignited a debate that has raged for nearly 20 years, sparking fierce arguments about how complexity evolved in animals.
