Code for Zhang et al The demise of the giant ape Gigantopithecus blacki

The largest ever primate, and one of the largest of the southeast Asian megafauna, Gigantopithecus blacki1, persevered in China from ~2.0 million years until the late middle Pleistocene when it went extinct2,3,4. Its demise is enigmatic considering that it was one of the few Asian great apes to go extinct in the last 2.6 million years when other great apes, including orang-utan, survived up to the present5. The cause of G. blacki's abrupt disappearance remains unresolved but could shed light on primate resilience and the fate of other megafauna in this region6. Here, we applied three combined multidisciplinary analyses concerning the; 1) chronology, 2) past environments, and 3) behaviour of G. blacki, to 22 caves in two regions of southern China. 157 radiometric ages from six dating techniques were modelled to establish a timeline for G. blacki demise. We show that from 2.3 Ma the environment was a mosaic of forests and grasses, which supported the flourishing G. blacki, and many other primate populations. However, just prior to and during the extinction window between 295-215,000 yrs ago (ka) there was enhanced environmental variability due to an increase in seasonality, which caused a change in forest plant communities and an increase in open forest environments. The data reveal that although its taxonomic relative Pongo weidenreichi was able to adapt its dietary preferences and behaviour to this variability, G. blacki displayed signs of chronic stress and struggled to adapt, causing dwindling populations and ultimately this led to the demise of the greatest hominid to walk the Earth.有史以来体型最大的灵长类动物，同时也是东南亚巨型动物群中体型最大的类群之一，步氏巨猿（Gigantopithecus blacki）在距今约200万年前至中更新世晚期的中国地区存续，最终走向灭绝²,³,⁴。 其灭绝的成因成谜，因在过去260万年的更新世以来，亚洲为数不多的灭绝大猿类群中，包括红毛猩猩（orangutan）在内的其他大猿均延续至今⁵。目前，步氏巨猿突然消失的原因仍未明确，但相关研究可为揭示该地区灵长类动物的生存韧性以及其他巨型动物的命运提供新的视角⁶。 本研究针对中国南方两个区域的22处洞穴遗址，开展了三项整合式多学科分析，分别聚焦于：1）步氏巨猿的生存年代学，2）其生存时期的古环境，以及3）该物种的行为模式。 研究整合了6种测年技术获得的157组放射性测年数据，通过建模构建了步氏巨猿的灭绝时间线。 结果显示，在距今230万年前的时期，该区域的生境为林草镶嵌的景观格局，这为步氏巨猿以及诸多其他灵长类种群的繁盛提供了适宜的生存条件。 然而，在距今29.5万至21.5万年的灭绝窗口期前后，由于季节性增强，环境波动显著加剧，这导致森林植物群落发生改变，开阔林生境的占比上升。 数据表明，尽管其分类学近缘物种魏氏红毛猩猩（Pongo weidenreichi）能够通过调整饮食偏好与行为模式来适应这种环境波动，但步氏巨猿却表现出慢性应激的特征，难以适应环境变化，最终导致种群数量持续缩减，进而引发了这种曾漫步地球的最大人科动物的灭绝。