Every time I look at it in the book store, I find the writing style of After the Ice a bit disconcerting, so I haven’t read it yet. For people who don’t know what I’m talking about, here’s an Amazon review that explains:

Using an unorthodox narrative device, Mithen explores why, how, and where farming displaced hunting and gathering. Mithen conjures John Lubbock, an English author of a once-popular 1865 history of the Stone Age, and sends him back in time to visit dozens of excavation sites around the world as they appeared when inhabited. Lubbock’s transcontinental perambulations permit Mithen (a practicing archaeologist who describes his digs in Scotland) to underscore one causal factor in the agricultural revolution: the fluctuations of climate at the end of the last Ice Age. Weather, sea level, and zones of plant and animal life changed dramatically in the 15,000 years of Lubbock’s walkabout, and Mithen explains how environmental volatility is scientifically known as he sketches Lubbock observing the various “living” human communities that have been uncovered.

But I should read it….

I see someone else mentioned migration paths above. Steven Mithen’s accessible and well-written After the Ice is a little more recent than Stuart, and you may find it interesting.

• Alan G. Fix, Rapid deployment of the five founding Amerind mtDNA haplogroups via coastal and riverine colonization,American Journal of Physical Anthropology, 2005.

Four major kinds of mitochondrial DNA are found in Amerindians; these are called haplogroups. A quote:

One of the central questions of Amerind prehistory is the time of entry of the original colonists. MtDNA provides some perspective on this question, but has not definitively resolved it. Thus various dates were derived for each of the haplogroups (Schurr, 2000), but these do not directly date the migration. Silva et al. (2002) argued for a common time of divergence of approximately 21 thousand years before present (ky BP) for sequences outside the control region of mtDNA from all four major haplogroups. In general, however, the data are too few and the methods too uncertain to provide a strong constraint on time of colonization.

Until recently, most archaeologists believed that the Pleistocene ice sheets barred the entry of Asian hunters into the American continent until the opening of the ice-free corridor around 11 ky BP (Dixon, 1999). Once the corridor was open, colonists rapidly expanded through the North American continent, exterminating the Pleistocene megafauna in a wave of advance that quickly spread to South America (Fiedel, 2000). The model based on this scenario was dubbed ‘‘blitzkrieg ’’ by Martin (1973) to emphasize the lightning-like pace of colonization, reaching the tip of South America in less than 1,000 years.

The classic blitzkrieg model sought to meet the perceived constraints of glacial timing and the dates provided by archaeologists for the earliest sites in the Americas. The critical dates were the opening of the corridor at ca. 11 ky BP and a series of radiocarbon dates for Clovis sites in North America at about the same time (11.2–10.8 ky BP). Since equally early sites were known from South America, a very rapid spread must have occurred in order to accommodate these dates (Dillehay, 2000).

Recent discoveries in South America, especially at the site of Monte Verde in Chile, forced a reconsideration of this view. It now appears that people were in South America by 12.5 ky BP, earlier than the opening of the ice-free corridor. Some suggest that this implies a much earlier presence of humans in North America, perhaps as much as 15–20 ky BP (Dillehay, 2000). In any case, the apparent constraint on timing of the entry provided by glacial barriers now seems removed.

Earlier views held that the coast as well as the continental interior of North America was blocked by ice. New evidence points toward an earlier deglaciation along the coast beginning about 16 ky BP, with a clear corridor by 14–13 ky BP (Dixon, 1999). Thus the date for a possible colonization route around the ice has been pushed back a bit. At the same time, the early dates of archaeological sites in South America indicate that the colonization process was rapid.

The apparent constraint on the timing of colonization that was satisfied by the blitzkrieg model has now been (partially) removed. An alternative view proposed by Fladmark (1979), that the original migrants entered the Americas along the coasts by boat, has gained increasing attention (Dixon, 1999). This paper will show that the coastal model is consistent with the mtDNA distributional evidence, adding support to this hypothesis.

The story so far is fascinating—I can’t wait for part two!

I didn’t mean to imply Beringia was glaciated. I said:

It seems likely that other people got to America earlier, moving down the Pacific coast before the inland glaciers melted.

What I meant here is that many experts believe the Clovis people moved south through a corridor between two glaciated regions in North America: the Cordilleran Ice Sheet and the Laurentide Ice Sheet.

But some experts now believe that other people moved down along the Pacific coast, perhaps with the help of boats, before the inland glaciers melted enough to form this corridor!

One glitch perhaps: Beringia never was glaciated. Wikipedia has a nice animation.

Apropos petroglyphs: There’s a swastika (with one leg missing?) above Antelope House. I knew it is a very old and widespread symbol (from Finnland to India), but never heard it was also used by ancient Americans. Did the Clovis people bring it across Beringia, or is it just an independently emerged “archetype”? The Anasazi were quite ingenious ornament artists.