“…It has also been suggested that many of the so-called typical Neanderthal traits are not Neanderthal autapomorphies but primitive fe atures that, because of their high frequencies and degrees of expression, and their distinctive combination, become typical of H. neanderthalensis species (e.g., Patte, 1962;Franciscus and Trinkaus, 1995;Bailey, 2002a;Martinon-Torres et al, 2006;Bailey et al, 2009;Hublin, 2009). Thus, the origin of the Neanderthal lineage would imply increasing frequencies of Neanderthal traits throughout time, favored by isolation due to glacial conditions (Arsuaga et al, 1993;Hublin, 1996Hublin, , 1998Dean et al, 1998). This is the basis for the fo rmula tion of the "accretion model," in which Neanderthal distinctions would accumulate gradually in populations (Dean et al, 1998;Hublin, 1998), so that earlier Middle Pleistocene populations should be "less Neanderthal" than later populations.…”