BREAKING: 400,000-year-old tooth proteins hint that Homo erectus may still “echo” inside living humans—via Denisovans.

In a May 2026 Nature study, researchers led by Qiaomei Fu recovered ancient enamel proteins (not DNA) from six Homo erectus teeth found at three Chinese sites—Zhoukoudian, Hexian, and Sunjiadong—all dated to roughly 0.4 million years. They identified two shared amino‑acid variants in the enamel protein ameloblastin (AMBN): one previously unknown (A253G) and another (M273V) that had been seen before in Denisovans.

Here’s the punch: Denisovans are known (from DNA) to have mixed with ancestors of some people alive today. The Nature paper argues that parts of the Denisovan genome tagged as “super‑archaic introgression”—and later pᴀssed on to modern humans—are likely to have originated from H. erectus, implying H. erectus and Denisovans overlapped and interbred somewhere in East Asia.

The headline claim needs care: this doesn’t mean a “Homo erectus gene” has been directly found in you. It’s a molecular breadcrumb trail—tiny protein differences preserved in enamel—pointing to ancient gene flow that could have reached us indirectly. What is undeniable is the method: proteins can survive where DNA fails, giving paleoanthropology a new way to test long‑debated “ghost lineage” scenarios