Dale, I'm not sure whether I want to contribute to keeping this part of the discussion going. First, because I'm not seeing any evidence that anyone else is interested, but second and maybe more importantly, I have some quibbles with the majority academic opinion. I wouldn't help anyone if I act like a pseudo-expert by giving my opinion, but I also don't want to just parrot back things that I don't necessarily agree about.
Skeletons are only a small part of how the picture gets created. Finding a skeleton with a particular haplogroup can help weaken or support a theory about migrations and dating, but the theories aren't based on where skeletons have been found.
Instead, there's a very basic theoretical idea that, in the absence of contrary evidence, groups originated in the same area where they have their greatest modern concentration AND greatest modern diversity. When they talk about diversity, they are really talking about the oldest branches of the group. If these branches are found only alongside other very old branches and if they're all in one small area and seem never to have moved anywhere else, that's taken to be an indication that the whole larger group is probably from that area.
Take Haplogroup G as an example. Most websites will tell you that it originated in the Caucasus or Turkey. However, you have to dig a little deeper to get the full picture. The greatest modern concentration of G is in the Caucasus mountains, but the greatest modern diversity is (apparently) in Turkey (Anatolia), just to the south. So, the origin must be somewhere around that area but no one is really sure how it happened.
Did it originate in Turkey and become concentrated in the Caucasus with tribes retreating into the mountains? Or did it originate in the mountains and move down into the plains very early in its history? Remember that there was probably a great deal of population flow between the two areas over thousands of years. That population flow obscures the picture.
There are old branches of Haplogroup G in Greece, and Crete. There are also very noticeable concentrations in Tuscany and the Alps, but in all four of these areas the branches are younger and there aren't a lot of other old branches around them. So, it looks like these are later migrations.
The oldest Hap G skeletons are from southern France and central Germany. They seem to have concentration, but again, not diversity.
So, it looks like Haplogroup G probably originated in the Caucasus, spread to Europe with the earliest farmers, and established some significant branches that appear only in Europe.
There are similar stories for all of the European haplogroups. The concentrations are "here" and "here", the oldest branches are "here", the people in this area are a branch of the people in that area. Pretty soon you have a good picture of the migrations, but sometimes there's a major breakthrough that causes minor revisions.
And this is one of the quibbles I have. You looked at the map. You saw the people entering Europe 45 000 years ago. I would argue that we don't actually know that directly.It's an assumption from indirect evidence. What we really know is that after the ice age (20 to 25 thousand years ago) Europeans spread out from refugia (refuges), in Spain and Ukraine. We also know that the populations that came out of those refugia were already mixed. So, it's logical to think that humans had already been in Europe, got pushed back by the ice into warmer climes, mixed while they were there, then spread out again behind the retreating ice. It's not that I think experts are wrong about any of that. It's just that I see a potential for confusion if we don't keep in mind that part of this is a leap of faith and could be overturned by new evidence someday.