A new study of human, Neanderthal, and Denisovan genomes pushes back the date our prehistoric cousins split off from early modern humans.

What they found: Neanderthals and Denisovans came from the same lineage that split off from ours about 744,000 years ago - almost 250,000 years earlier than previous studies indicated. Roughly 300 generations later — a fairly short time, in human evolutionary terms — the Neanderthals and Denisovans split off from each other.

Why it matters: Despite a growing number of fossils and a shared genetic history, we know fairly little about our most recent ancestors. We knew that Neanderthals and Denisovans were closely related enough to interbreed with each other and humans, but much of our shared past remains murky.

Past studies of Neanderthal genomes found they contained a high number of recessive genetic traits characteristic of inbreeding, which led researchers to conclude that there were only a few thousand Neanderthals in Europe. This study, however, estimates that there were tens of thousands of our ancient cousins in Europe, and that the high numbers of recessive mutations could be explained by living in small, genetically isolated sub-populations.

What they did: The scientists compared the genomes of modern Eurasians, modern Africans, and Neanderthal and Denisovans. They found some mutations were shared among all of the genomes, while others were only shared by Neanderthal and Eurasian genomes.

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Updated 4 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Aïda Amer/Axios

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Harris: "Women are going to be a priority" in Biden administration

Sen. Kamala Harris at an event in Wilmington, Del. Photo: Drew Angerer/Getty Images

In her first sit-down interview since being named Joe Biden's running mate, Sen. Kamala Harris talked about what she'll do to fight for women if elected VP, and how the Democrats are thinking about voter turnout strategies ahead of November.

What they're saying: "In a Biden-Harris administration women are going to be a priority, understanding that women have many priorities and all of them must be acknowledged," Harris told The 19th*'s Errin Haines-Whack.

Facebook goes after Apple

Illustration: Lazaro Gamio/Axios

Facebook is seeking to force a face-off with Apple over its 30% in-app purchase commission fee, which Facebook suggests hurts small businesses struggling to get by during the pandemic.

The big picture: Facebook has never publicly gone after Apple, a key strategic partner, this aggressively. Both companies face antitrust scrutiny, which in Apple's case has centered on the very fee structure Facebook is now attacking.