@Lebrok, in fact I like more fiction, and taking as example that of Yamnayan Indoeuropeans, I would need to choose between "The cradle of Indoeuropeans: Atlantis", because who could get ancient DNA from Atlantis to check if it matches the L51+ ? The plot would be that Atlanteans flied from their continent to Western Europe riding sirens... the other plot would be "The Saharan secrets, the Indoeuropean exodus", and as R1b V88 is in the Sahel... why not R1b L51+ was there also? then after the dissication of the Sahara the two brother clades split, one going to the south, the other to the north, to W. Europe... no archaeological proofs for that? well, Yamnayans also are not suppling proofs so I think the scientific standards will be keept good yet, and WTF, the first Bell Beakers were more near to Africa than to the steppe, even more credible...
@bicicleur, the first R1b "Yamnayan" is the Z2016+ found in Armenia of the Kura-Araxes culture (maybe proto-Hurrian), the second one would be the Manean recently provided (Manean possibly related to Hurro-Urartian), and also it seems that it could be added the proto-Urartian of Kapan, in Armenia, which has a date similar to the Tepe Hasanlu DNA and it's relatively quite near of him. I suppose that a good Yamnayist would deal with them thinking that they were IE herders wandering there looking for a lost sheep.