Pleistocene water crossings, long thought to be an innovation of Homo sapiens, may extend beyond our species to encompass Middle and Early Pleistocene Homo. However, it remains unclear how water crossings differed among hominin populations, the extent to which Homo sapiens are uniquely flexible in these adaptive behaviors, and how the tempo and scale of water crossings played out in different regions. I apply the adaptive flexibility hypothesis, derived from cognitive ecology, to model the global data and address these questions. Water-crossing behaviors appear to have emerged among different regional hominin populations in similar ecologies, initially representing nonstrategic range expansion. However, an increasing readiness to form connections with novel environments allowed some H. sapiens populations to eventually push water crossings to new extremes, moving out of sight of land, making return crossings to maintain social ties and build viable founder populations, and dramatically shifting subsistence and lithic provisioning strategies to meet the challenges of variable ecological settings.

更新世水域穿越长期以来被认为是智人的一项创新，可能会超出我们的物种范围，涵盖中更新世和早更新世人。然而，目前尚不清楚古人类群体之间的渡水有何不同，智人在这些适应行为中独特的灵活性程度，以及不同地区渡水的节奏和规模如何发挥作用。我应用源自认知生态学的适应性灵活性假设来对全球数据进行建模并解决这些问题。渡水行为似乎出现在相似生态环境中的不同区域古人类群体中，最初代表了非战略性的范围扩张。然而，越来越愿意与新的环境建立联系，这使得一些智人种群最终将渡水推向了新的极端，离开了陆地的视线，通过返回渡口来维持社会联系并建立了可行的创始人群体，并极大地改变了生计和石器供应策略，以应对可变生态环境的挑战。