Bojan Pancevski, in his piece in Saturday’s Wall Street Journal, thinks a researcher has identified the origins of half of humanity:

For about half the people alive today, the story of where they came from just became clearer.
…
For centuries, historians and linguists have been searching for the cradle of the Indo-Europeans, an ancient people who shaped history and created the world’s largest language family, now spoken by over 40% of humanity. Now research led by David Reich, a geneticist at Harvard Medical School who specializes in the study of ancient populations, is making it possible to give a precise answer.

Maybe not so precise.

DNA detectives, including at Reich’s lab, analyzed DNA samples from the remains of around 450 prehistoric individuals taken from 100 sites in Europe, as well as data from 1,000 previously known ancient samples. In two papers published in the scientific journal Nature last month, the researchers combine genetic evidence with archaeology and linguistics to argue that sometime before 3000 BC, a previously unknown people migrated from the Volga River to the Ukrainian steppe north of the Black Sea, where they mixed with a local population and formed the Yamnaya.

All of that, though, only begs a number of questions.

Who were those previously unknown people?

Where did they come from before the Volga?

Why did they migrate?

Who were the local population people?

Where had they come from?

What were the climate pressures then?

Pushing the origins answer back in time is useful and important, but these data don’t provide data for the origins of half of humanity.