The Climate Driven Migration Map Hidden in Ancient DNA

This is a fascinating topic, but what are the error bars are on the DNA analysis and temperatures?

I’m not convinced a 0.4°C change in temperature is always significant everywhere to migration.

That relatively small change has already been exceeded since 1850 while the world’s growing climates have been pretty stable, if not expanding from more CO2, warmth, and rain. Crops have not largely been displaced or decreased through the latest 0.4°C change, albeit crop production since 1850 has also been a matter of petroleum energy and technology, not just nature.

Perhaps crop migrations/changes are naturally less sensitive to ‘changes’ and are more a non-linear function of absolute temperature range. Maybe the study could be made better and more useful by including absolute temperature ranges.

A growing population will inevitably diffuse outward in preferential directions as it grows, after most of the nearby lands are taken up from population growth and use. Thus many migrations will naturally follow after long periods of population growth fed by good growing conditions. This would indicate population density is a factor in migration.

I’m also not convinced South Americans are presently ‘migrating’ to North America, specifically the USA, to escape climate change in South America – it is politically and economically imposed.

Or do a certain percentage of people through history always have a bad case of wanderlust?