Thank you. That’s interesting. I wonder if anyone has studied that dissipation rate. I remember reading that the blood was Rh neg. I hadn’t heard before that that might be due to the age of the blood. Is there blood from the Medieval ages that doesn’t test Rh neg?
Again, hard to tell. This is an example of study of the Shroud of Turin driving studies in other areas of science. The Shroud is the single most studied object in history, and it spins off more questions than are answered as scientists seek answers. That Rh factor question arose because of studies on ancient blood spurred by the ancient blood on the Shroud. Prior to that there really was little interest in finding old blood stains. Now there is.
Here’s an alternative hypothesis other that the hypothesis of dissipating Rh positive proteins over time. Suppose instead that the Rh positive protein comes from a new virus that has only appeared in the last one thousand to two thousand years infecting certain humans who may be genetically vulnerable. After all, not everyone tests Rh positive. Perhaps no one was Rh positive 2000 years ago and it just started becoming present in more and more of that genetically predisposed portion of the population who were more likely to be infected? Which is more likely to be true? I don’t know. How do we falsify either hypothesis?