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In all the early chaos, a thousand Plutos may have formed in the distant part of the solar system where Neptune orbits today, including a nascent Ceres. Then the shifting gas giants scattered those bodies everywhere. “In the great rearrangement of the solar system, Pluto went outward, Ceres came inward,” says planetary scientist and New Horizons co-investigator William McKinnon. He proposed Ceres’ migration in 2008 — the first hint of a potential sibling relationship betw ...read more

“It’s always been hard in theory to build from pebble-sized chunks that will naturally form out of the solar nebula, up to things that are tens of miles or hundreds of miles across,” says New Horizons scientist John Spencer at the Southwest Research Institute. In computer models, these objects tend to destroy each other when they collide. Astronomers are starting to suspect that the pebbles mixed with gas in the early solar system and then clumped together, growing from pebbles ...read more

Researchers have partially hidden Earth’s largest life-form behind a small protective fence. On a cold, sunny October day, I travel with Paul Rogers, an ecologist at Utah State University, to see the largest known living organism on Earth. The creature resides in the high mountains of southern Utah on public land. It’s a 106-acre aspen stand named Pando — literally, “I spread,” in Latin. Linked by a single root system, Pando consists of tens of thousands of gen ...read more

Animals also played an important role in Egyptian iconography. Gods were frequently portrayed as animal-human hybrids. For instance, the god of writing, Thoth, was sometimes shown with the body of a man and head of an ibis. The origin of this practice remains as elusive as the rise of those animal cults. But Barbash suspects it may relate to the relative ease of life in the lush Nile Valley, where people had the time to observe animal behavior and associate divine attributes with the traits of b ...read more

1. With territories stretching from Arctic ice to south of the equator, the eight members of Ursidae include the planet’s largest land predators — and a seriously sketchy family tree. 2. For decades, researchers have struggled to chart the evolution of bears. A genomic analysis published in Scientific Reports in April explained why: Gene flow between different species is common and can result in fertile hybrids. 3. You may have heard about pizzlies and grolars, the offspring of grizz ...read more

A toxic fungus infects crops eaten across the developing world. Scientists are engineering a solution. More than 10,000 years ago, somewhere in the Andean foothills between Argentina and Bolivia, two wild legume species mixed, probably with the help of some pollinating bees. Their offspring was atypical — a freak of nature that couldn’t remix with its wild ancestors and cousins. The freak plant continued to evolve, first on its own, and then by selection as farmers domesticated ...read more

For more than a century, the Natural History Museum of Los Angeles County has exhibited exotic specimens from around the world. But recently that global focus has shifted, as biologists recognize that LA itself is among the planet’s most diverse ecosystems. A new Urban Nature Research Center is enlisting citizen scientists to catalog species that they find in their backyards, from spiders to squirrels. Their goal is to better understand how biodiversity is affected by urbanization and glob ...read more

High HDL levels don’t always mean a lower risk of heart attack. Open the freezer in the laboratory across the hall from Annabelle Rodriguez’s office at the University of Connecticut Health Center, and you will find rows of miniature fluid-filled vials, many of them holding tiny strands of DNA. For the past 13 years, Rodriguez, a physician-scientist in the university’s Center for Vascular Biology, has kept her eye on one particular gene in those DNA strands that is integral ...read more

(Credit: Foxys Forest Manufacture/Shutterstock) If you want to teach your children the alphabet while mildly traumatizing them at the same time, look no further than “The Gashlycrumb Tinies.” In alphabetical order, and with a jaunty rhyme scheme, 26 children meet fates both gruesome and preposterous. In the future, though, as climate change warms the planet beyond our comfort zone in many regions, the book could be rewritten by adding some heat. There are 27 ways that a h ...read more