The Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.
Center for Macroecology, Evolution, and Climate, GLOBE Institute, University of Copenhagen, Copenhagen, Denmark.
Ecol Lett. 2022 Jan;25(1):125-137. doi: 10.1111/ele.13911. Epub 2021 Nov 5.
Pathways to extinction start long before the death of the last individual. However, causes of early stage population declines and the susceptibility of small residual populations to extirpation are typically studied in isolation. Using validated process-explicit models, we disentangle the ecological mechanisms and threats that were integral in the initial decline and later extinction of the woolly mammoth. We show that reconciling ancient DNA data on woolly mammoth population decline with fossil evidence of location and timing of extinction requires process-explicit models with specific demographic and niche constraints, and a constrained synergy of climatic change and human impacts. Validated models needed humans to hasten climate-driven population declines by many millennia, and to allow woolly mammoths to persist in mainland Arctic refugia until the mid-Holocene. Our results show that the role of humans in the extinction dynamics of woolly mammoth began well before the Holocene, exerting lasting effects on the spatial pattern and timing of its range-wide extinction.
灭绝的途径早在最后一个个体死亡之前就开始了。然而，早期种群减少的原因以及小的剩余种群易灭绝的原因通常是孤立地研究的。我们使用经过验证的过程明确模型，分解了在猛犸象最初减少和后来灭绝过程中起作用的生态机制和威胁。我们表明，要使猛犸象种群减少的古 DNA 数据与灭绝地点和时间的化石证据相协调，需要具有特定人口统计学和生态位限制的过程明确模型，以及气候变化和人类影响的约束协同作用。经过验证的模型需要人类使气候驱动的种群减少提前几千年，并允许猛犸象在全新世中期之前在大陆北极避难所中生存。我们的研究结果表明，人类在猛犸象灭绝动态中的作用早在全新世之前就开始了，对其分布范围灭绝的空间模式和时间产生了持久的影响。
