Plankton collected in the Pacific Ocean with a 0.1mm mesh net. Seen here is a mix of multicellular organisms — small zooplanktonic animals, larvae and single protists (diatoms, dinoflagellates, radiolarians) — the nearly invisible universe at the bottom of the marine food chain. Christian Sardet/CNRS/Tara Expeditions hide caption

itoggle caption Christian Sardet/CNRS/Tara Expeditions

This fungus among us — baker's yeast, aka Saccharomyces cerevisiae — is useful for more than just making bread. iStockphoto hide caption

itoggle caption iStockphoto

Men in hazardous materials suits load dead poultry to be buried at Rose Acre Farms Inc., just west of Winterset, Iowa, on May 11. John Gaps III/AP hide caption

itoggle caption John Gaps III/AP

The White House announced an action plan Tuesday aimed at reversing dramatic declines in pollinators like honeybees, which play a vital role in agriculture, pollinating everything from apples and almonds to squash. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images

The most recent common ancestor of all today's snakes likely lived 120 million years ago. Scientists believe it used needle-like hooked teeth to grab rodent-like creatures that it then swallowed whole. Julius Csotonyi/BMC Evolutionary Biology hide caption

itoggle caption Julius Csotonyi/BMC Evolutionary Biology

NOAA Fisheries biologist Nick Wegner holds an opah caught during a research survey off the California coast. Researchers say the opah is the first fish known to be fully warmblooded, circulating heated blood throughout its body. NOAA/Reuters/Landov hide caption

itoggle caption NOAA/Reuters/Landov

Numbat populations once dropped as low as 500 adults. To help save this endangered marsupial, the Perth Zoo has been rearing them in captivity for release back into the wild. But wild numbats eat only termites, which are too difficult to get in large quantities. So zoo staff have spent over a decade concocting a tasty and nutritious substitute. Helenabella via Wikimedia Commons hide caption

itoggle caption Helenabella via Wikimedia Commons

The skull of a chicken embryo (left) has a recognizable beak. But when scientists block the expression of two particular genes, the embryo develops a rounded "snout" (center) that looks something like an alligator's skull (right). Bhart-Anjan S. Bhullar hide caption

itoggle caption Bhart-Anjan S. Bhullar

Sheep are sold in small lots like this one at the Centennial Livestock Auction in Fort Collins, Colo. Luke Runyon/Harvest Public Media/KUNC hide caption

itoggle caption Luke Runyon/Harvest Public Media/KUNC

Welcome to America! Before it was spotted in Los Angeles, the fruit fly species Drosophila gentica had been seen only in El Salvador back in 1954. Courtesy of Kelsey Bailey, Natural History Museum of Los Angeles County. hide caption

itoggle caption Courtesy of Kelsey Bailey, Natural History Museum of Los Angeles County.

A woolly mammoth skeleton gets auctioned off in Billingshurst, England. Peter Macdiarmid/Getty Images hide caption

itoggle caption Peter Macdiarmid/Getty Images

Sir David Attenborough at the Beijing Museum of Natural History with fossil of Juramaia, as featured in the Smithsonian Channel series Rise of Animals: Triumph of the Vertebrates. Courtesy Smithsonian Channel hide caption

itoggle caption Courtesy Smithsonian Channel

Loki's Castle, the field of deep sea vents between Norway and Greenland, is home to sediments containing DNA from the newly discovered archaea. R.B. Pedersen/Centre for Geobiology, Bergen, Norway hide caption

itoggle caption R.B. Pedersen/Centre for Geobiology, Bergen, Norway

Author Barry Estabrook says pigs can be taught to play computer games and recognize themselves in a mirror. W. W. Norton & Company hide caption

itoggle caption W. W. Norton & Company