The ex-Governor of Alaska didn't quite say, "I can see Russia from my house!" -- that was her separated-at-birth look-alike, Tina Fey, on SNL. Kidding aside, on a clear day you really can see the Russian mainland from the Alaskan mainland, 55 miles away. It's a lot easier if you're in the middle of the Bering Strait, on Alaska's Little Diomede Island on the east side of the International Dateline. Russia's Big Diomede is less than 2 1/2 miles west, on the other side of the Dateline. Lynne Cox famously swam the gap, from Friday to Saturday, in 1987.
For tens of millions of years, land straddled present-day Bering Strait. It's usually called the "Bering Land Bridge," but that's a misnomer. A bridge summons up an image of a narrow dyke being traversed, single file, by woolly mammoths, moose, musk oxen, horses and camels. In reality, "Beringia" (as geologists call it) was actually a thousand-mile-wide, continent-sized steppe in which plants and animals thrived, dispersing themselves and their genes slowly and unwittingly from west to east. Today most of Beringia lies on the bottom of the Bering and Chuckchi Seas.
Beringia is a real-life Atlantis, except that while the sunken Atlantis of Plato's dialogues is an allegorical myth, Beringia is not only real but the key to understanding the distribution of much of the fauna and flora now living on Earth, including humankind. Towards the end of the last Ice Age, somewhere between 10,000 and 20,000 years ago -- perhaps more, according to a minority of archaeologists -- groups of homo sapiens unwittingly migrated from Asia into the Americas, probably in three main waves. The descendants of those hardy folk spread south all the way to Tierra del Fuego, and by the time Columbus arrived, at least 50 million people were living in the New World.
As the Earth warmed, ice melted and sea levels rose about 140 feet, slowly covering Beringia. The sea broke through about 8,000 years ago and the channel widened. And now, as Sarah Palin (actually) said, "...you can actually see Russia from land here in Alaska."
Barry Evans (firstname.lastname@example.org) doesn't even swim in the bay (unlike his wife), let alone the Bering Strait.
CAPTION: "Beringia" then and now. Left, 18,000 years ago, at the height of the last Ice Age when the sea level was 140 feet lower than now. Right, present.