According to a scientific paper published in May of 2016, there have been multiple human migrations into Europe during the last 45,000 years. Listed below is a summary of the three major events.
45,000 years ago: This is widely considered the first migration of anatomically modern humans into Europe. Until then, Europe was populated by Neanderthals, but the disappearance of Neanderthal tools after this event provides evidence modern humans replaced them.
19,000 years ago: Between 25,000 and 19,000 years ago, large ice sheets covered much of Europe, confining humans to the southern reaches of the continent. The ice sheets began to recede and modern humans from southwestern Europe (Spain) migrated into the northern areas.
14,000 years ago: Although the paper does not describe the cause of this last migration, it was a major event that upturned European ancestry. This time, people from the southeast (Greece, Turkey) were the ones moving into the northern areas.
It is interesting to note this last event occurred just before the construction of Gobekli Tepe (GT) in southwestern Turkey, which was built at least 12,000 years ago. I liberally use the term “just before” because dates are still uncertain. Perhaps we will find archaeological evidence that the deepest layers of GT are even older than expected. Or perhaps we will someday find temples related to GT, but older still.
So is the timing a coincidence? Were the people who built GT the ones who migrated into Europe 14,000 years ago? Was it their ancestors? Only time will tell. More evidence will answer these questions. More data is needed comparing the migrants with the culture that built GT. Excitingly, new finds may also provide insight into why GT was built in the first place and why the site was abandoned multiple times over millennia.