In 1600 BC, it is not even clear if a Celtic language group had split from Indo-European. The first archaeological stage identified as "Celtic" is the Hallstat culture (800 BC-400 BC) which is generally confined to the Alps. It's not until the La Tène Era (400 BC-44 BC) that significant Celtic artifacts are found in the British Isles. Although the question of when the Celts arrived in Britain and Ireland is debated, most scholars assume it occurred well after 1600 BC.

One of the oldest human skeletons ever found in North America may be repatriated to several American Indian tribes for reburial within two weeks. The well-preserved skeleton was found on July 28 in the Columbia River in Kennewick, Washington, by two residents of nearby West Richland. It has been radiocarbon-dated to 8410 ± 60 B.P. (before present) by R. Ervin Taylor, Jr., of the University of California, Riverside, and this date is broadly corroborated by a piece of a projectile point of the Cascade phase, usually dated between ca. 9000 and 4500 B.P., embedded in the pelvis. Archaeologists are fighting the repatriation of the skeleton before it has been studied further, and a legal challenge may be launched.

Examination of the skull by anthropologist James Chatters revealed a long, narrow skull and face, a projecting nose, receding cheek bones, a high chin, and a square mandible. None of these features is typical of modern American Indians, but they are found on other Paleoindian skeletons roughly contemporaneous with the Kennewick remains. Such features have previously been described as "pre-mongoloid," "proto-mongoloid," "archaic-mongoloid," and even "proto-caucasoid."

The last term, in particular, has led to some confusion, with New York Times reporter Timothy Egan calling the skeleton "Caucasian" and saying, "It adds credence to theories that some early inhabitants of North America came from European stock." But according to anthropologist Donald K. Grayson of the University of Washington, "the use of the term caucasoid really is a red flag, suggesting that whites were here earlier and Indians were here later, and there's absolutely no reason to think that."

In a 1994 study, physical anthropologists D. Gentry Steele and Joseph F. Powell, both of Texas A&M University, compared the morphology of early North American skulls with that of other ancient and modern groups from around the world. They observed that later Holocene (ca. 8500 B.P.-present) northern Asians and American Indians fall into one group, with the shortest, widest faces; southern Pacific and European populations into a second group, with the tallest, narrowest faces; and Paleoindians into a third group somewhere in between. They concluded that their "analysis supports the distinctiveness of the Paleoindian sample from the more recent Holocene American Indians."

Whether these differences are the result of two (or more) separate migrations from Asia to North America; of the evolution over the past 10,000 years of the shorter, rounder skull shape out of the taller, narrower one; or of some other cause remains undetermined. Steele and Powell based their study on observations of nine skeletons between 8,000 and 10,000 years old and more detailed measurements of four of those, omitting a tenth because its date was uncertain. Since then several other skeletons of similar age have come to light. At least one of them, known as the Spirit Cave Man (see "Oldest North American Mummy," ARCHAEOLOGY, September/October 1996), also displays the taller, narrower skull morphology, according to Amy Dansie of the Nevada State Museum in Carson City. As one of the best-preserved New World skeletons of the period, the Kennewick specimen has the potential to contribute greatly to this discussion, but it may be reburied before scientists can study it further.