Saturday, January 13, 2007

Understanding our Ancestors

The press is reporting that modern humans arrived in Europe about 45,000 years ago according to a new study to be published in the journal Science. The research theorizes the arrival of people exactly like us in Russia about ten thousand years earlier than previously believed. The change in the historical timeline is based on acceptance that a layer of volcanic ash present at the historic Kostenki archeology sites is from an Italian eruption 40,000 years ago. The logic being that evidence of modern humans beneath this ash layer must be older.

Earliest evidence of modern humans in Eastern Europe: The excavations are located in the villages of Kostenki and Borshchevo, on the low terraces just above the Don River, overlooking a broad valley. Holliday says the uplands at Kostenki closely resemble rural Iowa. … The notion that modern people lived that long ago in what was then a sub-Arctic region intrigued Holliday, who analyzed the stratigraphy of the sites.

This is a good example of the difficulty with precision in statements of events in the distant past. A UW Madison archeologist comments on the timeline change forced by the geologic evidence.

John Hawks: It is interesting that much of the way toward the older date on the radiocarbon dates comes from calibrating them. … The calibration here is enough to make a 37,000 14C date into a 42,000 year calibrated date.

If the initial UP at Kostenki can be redated 10,000 years earlier, and if dozens of radiocarbon dates earlier than 32,000 years can unilaterally have 5000 or more years added to them, this inspires little confidence in the existing radiocarbon chronology of Europe. Of course, we've been seeing changes in radiocarbon chronology for many years now. Still, the scale of this change is very impressive.

The problems with carbon 14 dating are well known (see Carbon-14 Dating and Wikipedia) and are in a large part to due the variable nature of the sun’s energy that is the source of production for this unstable isotope.

Radiocarbon Dating: Fourth, the ratio of C-14 to C-12 in the atmosphere is not constant. Although it was originally thought that there has always been about the same ratio, radiocarbon samples taken and cross dated using other techniques like dendrochronology have shown that the ratio of C-14 to C-12 has varied significantly during the history of the Earth. This variation is due to changes in the intensity of the cosmic radiation bombardment of the Earth, and changes in the effectiveness of the Van Allen belts and the upper atmosphere to deflect that bombardment.

In other words, there is evidence the energy from the sun varies over time as does the climate of planet. The sub artic environment associated with the first remains of modern people in Europe has completely changed over the tens of thousands of years.

Kostenki Evidence: Pollen records indicate an evolution of the vegitation from pine forest conditions to forest with the dominant of spruce (Picea) of tiaga type and to the meadow-steppe associations. The climat change from cold to temperate, relatively warm and humid correspond to the interglacial environment in the lower part and to the beginning of glaciation in the upper part of the deposits of the lower humic bed.

Almost every day the press reports statements implying climate change is unnatural and detrimental. There is a disturbing trend to actively suppress any challenge to the assumptions. Real science is always open to disbelief and evidence to the contrary. The difficulty of precision in describing the last several thousand years based on actual observations should be a warning to believing the precision of software generated projections of future adverse consequences.