加州大学伯克利分校的研究人员利用新型遗传学方法，在现代人类DNA中识别出两个已灭绝人类祖先群体的遗传痕迹[1]。其中一个"幽灵祖先"在50,000多年前与现代人类在非洲发生混杂，为现代人类基因组贡献了约1%的遗传物质，这一贡献比例与尼安德特人相当[1]。该幽灵祖先血统与现代人类祖先的分离时间约为800,000年前[1]。
另一个"超古老祖先"的血统可追溯至约180万年前，其遗传物质可能在200,000多年前通过丹尼索瓦人传递给现代人类[1]。现代人类基因组中约2%来自这些古老人族[1]。研究团队采用了TRACE方法（通过遗传重组图估计追踪古老贡献），通过分析现代人类基因组而非依赖古代化石DNA进行分析[1]。这项研究于2026年7月30日发表在《科学》期刊[1]。
Priya Moorjani教授表示："人类进化不是分支树，而是由重复迁移和混杂连接的复杂网络"[1]。
Researchers at UC Berkeley have identified genetic traces of two previously unknown extinct human ancestor populations hidden within modern human DNA through a novel genetic analysis method.[1] One "ghost ancestor" interbred with modern humans more than 50,000 years ago in Africa, contributing approximately 1% to the modern human genome—a proportion comparable to the genetic contribution from Neanderthals.[1] A second, far more ancient lineage can be traced back approximately 1.8 million years and likely interbred with Denisovans over 200,000 years ago, passing small amounts of genetic material to modern humans through that intermediary population.[1]
The discovery reveals a far more complex history of human evolution than previously understood.[1] The ghost ancestor's lineage diverged from modern human ancestors roughly 800,000 years ago,[1] while approximately 2% of the modern human genome derives from these ancient hominin groups combined.[1] The research employed the TRACE method (Tracing Ancient Contributions through ARGs Estimation), which analyzes patterns in modern human genomes rather than relying solely on ancient fossil DNA.[1] The findings were published in Science on July 30, 2026.[1]
According to Priya Moorjani, a professor leading the research, the results underscore a fundamental rethinking of human evolutionary history: "Human evolution is not a branching tree, but rather a complex network connected by repeated migration and admixture."[1]