The deep evolutionary roots of Cannabis and Humulus: fossils, genomics, and geography

Although the duo Cannabis and Humulus includes some of the earliest and most versatile domesticated plants, their evolution remains poorly understood. We revise the fossil record of Cannabis and Humulus to constrain the age and geographic location of the plants. Exquisite fossils from the Eocene of North America assigned to Humulus lupulus, suggest that the common hop may represent a true ‘living fossil’ that has experienced a prolonged period of evolutionary stasis. Our molecular clock analyses reveal that the common ancestor of Cannabis and Humulus diverged in the Eocene to Paleocene, coinciding with the emergence of steppe biomes in Eurasia during the late Eocene, constraining the geographical origin of both plants and offering a framework for testing causal hypotheses of their divergence.

尽管大麻和啤酒花这对组合包含了一些最早且适应性最强的驯化植物，但其进化过程仍处于理解不足的状态。我们对大麻和啤酒花的化石记录进行了修订，以限定这些植物的年代和地理分布。来自北美始新世的精致化石，被归为啤酒花属（Humulus lupulus），暗示了普通啤酒花可能是一种真正的‘活化石’，经历了漫长的进化停滞期。我们的分子时钟分析揭示，大麻和啤酒花的共同祖先在始新世至古近纪时期发生分化，与欧亚大陆在晚始新世出现的草原生物群落的出现相吻合，从而限定了这两种植物的地理起源，并为测试其分化的因果假设提供了一个框架。