Most archaeologists think the first Americans arrived by boat. Now, they're beginning to prove it
17,000-Year-Old Coastal Route Into North America Revealed
The Startling Alternative Theory of How Humans Arrived in America
Early primate ancestor may have come from North America
The North European hypothesis was a linguistic and archaeological theory that tried to explain the spread of the Indo-European languages in Eurasia from an original homeland (Urheimat) located in southern Scandinavia or in the North German Plain. This hypothesis, advanced by Karl Penka, Hermann Hirt, Gustaf Kossinna and others, had some success in the late nineteenth century and the early twentieth century being endorsed by National Socialism but is today considered outdated by the majority of the academics who tend to favor the Kurgan hypothesis.
It has been recently recovered by Jean Haudry and Carl-Heinz Boettcher.