Animal DNA in PCR reagents plagues ancient DNA research

Molecular archaeology brings the tools of molecular biology to bear on fundamental questions in archaeology, anthropology, evolution, and ecology. Ancient DNA research is becoming widespread as evolutionary biologists and archaeologists discover the power of the polymerase chain reaction (PCR) to amplify DNA from ancient plant and animal remains. However, the extraordinary susceptibility of PCR to contamination by extraneous DNA is not widely appreciated. We report the independent observation of DNA from domestic animals in PCR reagents and ancient samples in four separate laboratories. Since PCR conditions used in ancient DNA analyses are extremely sensitive, very low concentrations of contaminating DNA can cause false positives. Previously unidentified animal DNA in reagents can confound ancient DNA research on certain domestic animals, especially cows, pigs, and chickens.     

The Four Corners of Our Brain

Throughout religious, scientific, and humanist literature on ideas one finds categorical subdivisions that are four in number: the four corners of the Earth, the four cardinal directions, the four proteins constituting DNA, Maxwell's four equations, Toynbee's four societies, Pythagoras’ four elements of arithmetic, Pythagoras’ four elements, Hayden White's four aspects of imagination. The list is endless. From where does the “four” come? Why not five, or six, eight, or nine? Andersen tracks back to the beginnings of arithmetic utilized in the architecture of conceptual thinking. He finds the answer not only in the quadration of the human body as having four sides and giving a stabilizing structure to the brain but equally in the architecture of memory. Using the slot-theory of short-term memory processing, he demonstrates how easily the four-count comes to mind and how the brain resists moving on to five.     

BABYLONIAN WISDOM LITERATURE AND THE MARDUK CYCLE:PRELIMINARY THOUGHTS

This paper, first prepared and delivered for a workshop on teaching Biblical Wisdom Literature in China, provides me with the opportunity, so to speak, to kill two birds with one stone. Not only will I comment on the main theme of the