Antiquity’s miracle skin whitening method: migrate to Sweden, wait millennia

Welcome back to the Unsupervised Learning Journal Club, an occasional feature for paying subscribers where I review interesting papers in human population genomics. In the spirit of a conventional journal club, after each post, interested subscribers can vote on papers for future editions.

Recent editions:

• Wealth, war and worse: plague’s ubiquity across millennia of human conquest

• Where Queens Ruled: ancient DNA confirms legendary Matrilineal Celts were no exception

• Eternally Illyrian: How Albanians resisted Rome and outlasted a Slavic onslaught

• Homo with a side of sapiens: the brainy silent partner we co-opted 300,000 years ago

• Brave new human: counting up the de novo mutations you alone carry

• The wandering Fulani: children of the Green Sahara

• Genghis Khan, the Golden Horde and an 842-year-old paternity test

• Re-writing the human family tree one skull at a time

• Ghost Population in the Machine: AI finds Out-of-Africa plot twists in Papuan DNA

• Immigrants of Imperial Rome: Pompeii’s genetic census of the doomed

Free subscribers can get a sense of the format from my ungated coverage of two favorite 2024 papers:

• The other man: Neanderthal findings test our power of imagination

• We were selected: tracing what humans were made for

Unsupervised Learning Journal Club #11

Today we’re reviewing a PNAS paper, Inference of human pigmentation from ancient DNA by genotype likelihoods (2025). The authors use paleogenetics and the latest in genomic inference to shine new light on the evolution of pigmentation in Eurasia, and particularly in Europe. It comes out of Guido Barbujani’s lab in the Department of Life Sciences and Biotechnology, Universitá degli studi di Ferrara, Ferrara. The first author is Silivia Perretti, at the same university.

By your skin you shall be known

“Of the Ethiopians above Egypt [Nubia] and of the Arabians the commander, I say, was Arsames; but the Ethiopians from the direction of the sunrising (for the Ethiopians were in two bodies [Nubians and Indian]) had been appointed to serve with the Indians, being in no way different from the other Ethiopians [Nubians and Indians serving together], but in their language and in the nature of their hair only; for the Ethiopians from the East are straight-haired [India], but those of Libya have hair more thick and woolly than that of any other men [Nubians].”

— Herodotus, The Histories (Book 7, Chapter 70), circa 440 BC

Skin is our largest organ. It’s one of our most faithful indices of age and ...