Let no one say that I’m an uncritical voice about the many advantages of releasing preprints. They do have their downsides. Lack of editing is one.
Here’s a passage from a new preprint from Peter Waddell and Xi Tan, “New g%AIC, g%AICc, g%BIC, and Power Divergence Fit Statistics Expose Mating between Modern Humans, Neanderthals and other Archaics”:
The apparent lack of Denisovan alleles on the X chromosome suggested that some of these archaic interbreeding events were male biased, that is archaic males mating with modern females (Waddell, 2011). This was formerly dubbed the archaic Ron Jeremy hypothesis, after the well-known American thespian. Formerly known, because a journal editor has recently urged us to alter our manuscript, to avoid confusion with a Ron Jeremy Event, which they referenced to the Urban Dictionary. The new synonymy is the lecherous archaic man hypothesis.
I’ll return to the argument in the paper later, I just wanted to consider the question of Neandertal similarity to well-known thespians. This is a followup to another preprint from last 2011, which addressed the question of male-biased gene flow into the ancestry of Papua New Guinea from Denisovan peoples (“Homo denisova, Correspondence Spectral Analysis, Finite Sites Reticulate Hierarchical Coalescent Models and the Ron Jeremy Hypothesis”). From that preprint:
While the origin of the unusual features of the NSYFHP pattern is just a hypothesis at this stage, it is testable and deserves a name, so we call it the Ron Jeremy hypothesis (after the accomplished American thespian Ron Jeremy, who is adroit at debauching modern young women, whose fathers might well call him a Neanderthal or a Denisovan, and who looks remarkably like reconstructions of these archaic humans in museums, including being very big boned).
Similarly, we may refer to the low frequency of the NSYFHP on the X chromosome as Rons Grandfather hypothesis which is the mixing of the Denisovan lineage with an even more ancient hominid lineage due to a male biased infusion.
Obviously we badly, badly need a better system of terminology to discuss the relationships of archaic human groups, including MSA and earlier Africans, which we now understand to have been subject to recurrent gene flow. Male-biased gene flow has often happened in human groups, sometimes due to warfare or the dominance of elites, sometimes as a simple function of greater male dispersal. Male-biased gene flow also appears to characterize orangutan population history, but not chimpanzees, so it depends on species-specific aspects of population structure and dispersal strategies.
We unfortunately have a 150-year history of looking at Neandertals, and secondarily at other archaic human groups, as strange evolutionary dead-ends. When faced with the evidence that these ancient people are among our ancestors, some scientists have turned first to the idea that mating among ancient people was exotic and strange. Hence the “Ron Jeremy” angle.