When humankind entered North America, fifteen thousand years ago or more, it entered a world of giants-woolly mammoths, dire wolves, sabre-toothed cats, short-faced bears (effectively grizzlies on stilts). But, by the end of the Ice Age, about ten thousand years ago, the megafauna was mostly gone, driven extinct by the warming climate and, many scientists think, predation by us.

A paper in this week's issue of Science Advances offers tantalizing evidence of that grim process in action. Archeologists working at White Sands National Monument, in New Mexico, found a series of fossilized footprints made by giant ground sloths, lumbering behemoths that once roamed North and South America. The tracks date to between ten thousand and fifteen thousand years ago, when the region was much wetter than it is today. The giant sloth was herbivorous but nonetheless a fearsome creature-eight feet tall when standing on its hind legs, with long arms, and long claws extending from its padded feet.

What's creepier than an old, desiccated mummy or a skeleton with a prosthetic knife-hand? How about an 11-foot-tall ominous wooden sculpture covered in strange faces, carved before recorded history and pulled out of a peat bog in Russia?

Sure, mummies are spooky (especially when they're locked in a tomb that promises to curse anyone who disturbs it), but they're less intimidating when you realize that their births and deaths were closer to us than they were to the ancient Shigir idol.

Unearthed in 1894 by gold miners in the Ural Mountains of Russia, the Shigir Idol was originally dated to be about 9,900 years old.

It's estimated to have originally been about 15 feet tall, though chunks of it are missing, and anthropologists noted that there were five faces carved on different parts of its human-like 'body', including the one on its head.

For as long as there has been civilization, there have been mind-altering drugs. Alcohol was fermented at least 10,000 years ago in the Fertile Crescent, about the same time that agriculture took hold there. Elsewhere, for example in Mesoamerica, other psychoactive drugs were an important part of culture. But the ancient Near East had seemed curiously drug-free-until recently.

Now, new techniques for analyzing residues in excavated jars and identifying tiny amounts of plant material suggest that ancient Near Easterners indulged in a range of psychoactive substances. Recent advances in identifying traces of organic fats, waxes, and resins invisible to the eye have allowed scientists to pinpoint the presence of various substances with a degree of accuracy unthinkable a decade or two ago.

For example, "hard scientific evidence" shows that ancient people extracted opium from poppies, says David Collard, senior archaeologist at Jacobs, an engineering firm in Melbourne, Australia, who found signs of ritual opium use on Cyprus dating back more than 3000 years. By then, drugs like cannabis had arrived in Mesopotamia, while people from Turkey to Egypt experimented with local substances such as blue water lily.

The Kets are an indigenous people who live in Siberia and are regarded to be one of the smallest ethnic groups in that region. Their appearance, language and traditional semi-nomadic lifestyle has scientists bewildered by their origins, with some proposing links to the native tribes of North America. There is even a Ket folklore that they came from space. What might be the true origin of these seemingly out of place people?

Ashkenazi Jews are a Jewish ethnic group who have their earliest ancestors from the indigenous tribes of Israel...at least on one side of the family tree. A study published in 2013 in Nature Communications has shown their maternal lineage comes from a different, and possibly unexpected, source.

The research shows the origins of the matrilineal line for the Ashkenazi Jews comes from Europe. This goes against the common belief that Jewish people first arrived in central Europe after the Byzantine-Sasanian War of 602-628 and only began settling in Germany in the Medieval period.

Ashkenazi Jews is the term used today to describe these Jewish people - individuals who built religiously-based communities centuries later in Central and Eastern Europe. One of the things they are recognized for is the use of Yiddish - a High German language written in the Hebrew alphabet and influenced by classical Hebrew and Aramaic.

A bitter wind whipped down the 10-mile-long Chaco Canyon, kicking up swirls of dust among the thorny greasewood and sagebrush bushes. I ducked behind one of the towering sandstone walls in the three-acre ruin, or Great House, known as Pueblo Bonito, to escape the gusts. I was in the section of the 800-room complex where burials took place. Treasure hunters and archaeologists have uncovered in these ruins and tombs delicate white-and-black painted ceramics, flutes, ceremonial sticks, tiny copper bells, inlaid bone, macaw and parrot skeletons, cylindrical jars with the residue of chocolate that would have been imported from Mexico, shells and intricate turquoise jewelry and sculptures. From this vast, bureaucratic and ceremonial complex, the Anasazi-a Navajo word meaning ancient ones or possibly ancient enemies-dominated the Southwest from about the year 850 until the society collapsed in about 1150.

The Chaco ruin, 6,200 feet above sea level, is one of the largest and most spectacular archeological sites in North America. It is an impressive array of 15 interconnected complexes, each of which once had four-to-five-story stone buildings with hundreds of rooms each. Seven-hundred-pound wooden beams, many 16 feet long, were used in the roofs. Huge circular, ceremonial kivas - religious centers dug into the earth, with low masonry benches around the base of the room to accommodate hundreds of worshippers - dot the ruins. It rivals the temples and places built by the Aztecs and the Mayans.

Odysseus, who voyaged across the wine-dark seas of the Mediterranean in Homer's epic, may have had some astonishingly ancient forerunners. A decade ago, when excavators claimed to have found stone tools on the Greek island of Crete dating back at least 130,000 years, other archaeologists were stunned-and skeptical. But since then, at that site and others, researchers have quietly built up a convincing case for Stone Age seafarers-and for the even more remarkable possibility that they were Neandertals, the extinct cousins of modern humans.

The finds strongly suggest that the urge to go to sea, and the cognitive and technological means to do so, predates modern humans, says Alan Simmons, an archaeologist at the University of Nevada in Las Vegas who gave an overview of recent finds at a meeting here last week of the Society for American Archaeology. "The orthodoxy until pretty recently was that you don't have seafarers until the early Bronze Age," adds archaeologist John Cherry of Brown University, an initial skeptic. "Now we are talking about seafaring Neandertals. It's a pretty stunning change."

Scholars long thought that the capability to construct and victual a watercraft and then navigate it to a distant coast arrived only with advent of agriculture and animal domestication. The earliest known boat, found in the Netherlands, dates back only 10,000 years or so, and convincing evidence of sails only show up in Egypt's Old Kingdom around 2500 B.C.E. Not until 2000 B.C.E. is there physical evidence that sailors crossed the open ocean, from India to Arabia.

But a growing inventory of stone tools and the occasional bone scattered across Eurasia tells a radically different story. (Wooden boats and paddles don't typically survive the ages.) Early members of the human family such as Homo erectus are now known to have crossed several kilometers of deep water more than a million years ago in Indonesia, to islands such as Flores and Sulawesi. Modern humans braved treacherous waters to reach Australia by 65,000 years ago. But in both cases, some archaeologists say early seafarers might have embarked by accident, perhaps swept out to sea by tsunamis.

Magnetic pole shifts are in the news a lot recently because our Magnetic North Pole is racing towards Russia while the Earth's magnetic field strength is falling fast. The European Space Agency said this could be the beginning of a magnetic pole shift. Evidence suggests the rotational axis will also shift to stay aligned with the magnetic field. These catastrophic pole shifts come in a periodic cycle of recurring and predictable cataclysms involving huge earthquakes and tsunamis, changes in latitude and altitude, mass extinctions, and the destruction of civilizations - reducing them to myth and legend.

New findings link genetic mutation to mammary duct growth as well as shoveled teeth

The critical role that breast feeding plays in infant survival may have led, during the last ice age, to a common genetic mutation in East Asians and Native Americans that also, surprisingly, affects the shape of their teeth.

The genetic mutation, which probably arose 20,000 years ago, increases the branching density of mammary ducts in the breasts, potentially providing more fat and vitamin D to infants living in the far north where the scarcity of ultraviolet radiation makes it difficult to produce vitamin D in the skin.

The mummified remains of Iranian leader Reza Shah Pahlavi may have been found during the excavation of a Shiite shrine in southern Tehran.

Pahlavi ruled Iran during World War Two before being succeeded by his son, Mohammad Reza Pahlavi, the country's last shah, who was overthrown during the Islamic Revolution of 1979. The elder Pahlavi had been buried in a nearby mausoleum after his death in 1944 but the tomb was later destroyed by Iranian revolutionaries. The body was never found in the ruins and has been missing for decades.

Hassan Khalilabadi, the head of Tehran City Council's cultural heritage and tourism committee, reportedly told the state news agency IRNA that it was a "possibility" that the remains uncovered at the Shiite shrine of Abdul Azim are those of Reza Pahlavi. Authorities say they will now conduct DNA tests to confirm if the body is indeed Pahlavi.