MICHIGAN: Between 10,000 and 7,500 years ago, the Alpena-Amberly ridge was high and dry, and home to caribou hunters. Now 100 feet below the surface of Lake Huron, the ridge has a series of stone features--hunting blinds and a 380-yard-long wall among them--that would have been used to guide prey into ambushes. Identified using sonar and a remotely operated vehicle, the site is the first evidence of human habitation found under the Great Lakes. (Courtesy Guy Meadows)

VIRGINIA: Surprising treasures continue to emerge from wells in the early-17th-century settlement of James-town. This season it is a slate covered on both sides with overlapping words, numbers, and faint sketches of birds, flowers, and nattily dressed men. "A MINON OF THE FINEST SORTE," the slate appears to read, below "EL NEV FSH HTLBMS 508." The mysterious phrases have yet to be interpreted. (Courtesy Preservation Virginia)

UNITED KINGDOM: For the first time, a "witch bottle," buried in the 17th century to ward off spells, has been opened under laboratory conditions. The rare intact example, found in 2004, contained bent pins, a nail-pierced heart made of leather, fingernail clippings, belly-button lint, and hair, all swimming in a bath of 300-year-old, nicotine-tinged urine. There's no indication whether it worked as expected. (Courtesy Mike Pitts, British Archaeology)

CZECH REPUBLIC: The Paleolithic Gravettian people of central Europe knew how to throw a mammoth-size barbecue. Excavations at the 31,000-year-old site of Pavlov VI have exposed a cooking pit with the remains of two mammoths, among other animals. The site also contains additional fire pits, flint knives, and bone tools, as well as clay that holds impressions of fingerprints, reindeer hair, and textiles. (Courtesy Antiquity)

SOUTH AFRICA: Stone tools from Sibudu Cave have a red residue on them--glue made from plant gum and ocher. The ocher's purpose was unknown until researchers re-created the glue and found that it improves the adhesive power of the gum, forming a kind of 70,000-year-old superglue to attach stone tools to wooden shafts. The difficult recipe appears to indicate complex cognition in early humans, including multitasking and abstract thought. (William Hobbs)

JORDAN: Excavations near the Dead Sea have revealed grain storage structures that predate the domestication of wild grains. The granaries, which had raised floors for air circulation and pest control, are more than 11,000 years old. They mark a significant evolution in the relationship between Neolithic humans and their food--toward agriculture and settled lifestyles. ( Courtesy Kuijt I., Finlayson B. PNAS;2009;106:10966-10970)

COOK ISLANDS: A new theory posits that Polynesians voyaged to faraway islands because some of their fish were toxic. Looking at fish bones, hooks, and climate records, researchers think that ciguatera fish poisoning, caused by algal blooms, may have driven the islanders to attempt risky ocean journeys in search of new homes and safer fishing grounds from the 11th to 15th centuries. Modern outbreaks have led to migrations to Australia and New Zealand. (Jackalyn Rongo)

AUSTRALIA: A tour guide and naturalist snapped pictures of some interesting rock art while exploring a cave. Experts now think the painting he shot depicts a marsupial lion (and not the more-commonly depicted Tasmanian "tiger" or thylacine), a six-foot-long predator that has been extinct for tens of thousands of years. The painting, which may be around 19,000 years old, includes details, such as stripes, a tufted tail, and pointy ears, that can not be seen in fossil remains. (Courtesy Lyn Wadley Robbins et al., DOI:10.1371/journal.pone.0005669)

INDIA: A skull from Balathal in Rajasthan holds the earliest known evidence for leprosy. The 4,000- year-old remains were buried in a stone enclosure and covered in ash from burnt cow dung--a sacred, purifying substance in the pre-Hindu Vedic traditions--and will help explain the notoriously elusive origins and prehistoric transmission patterns of the chronic disease. (Courtesy Colin Cooke)

PERU: Pollution isn't just a modern problem. In cores of high-altitude lake sediments, scientists have discovered the earliest clear proof of pre-industrial mercury pollution. As far back as 1400 B.C., before the rise of large Andean societies, people near the contemporary town of Huancavelica mined cinnabar (mercury sulfide) to make vermillion pigment. Around 3,000 years later, at the peak of Inca civilization, they heated the heavy metal, creating mercury vapor, which is extremely toxic and polluted a lake more than 100 miles away. (Courtesy Teina Rongo)