Evolutionary changes to Homo body size and proportionality across 800,000 years of global climate change

The challenge with testing the impact of climate change on hominins is a lack of comparable sample data. Few intact skeletons exist, and body size estimates are difficult to ascertain with only fragmentary skeletal remains. What measurements are available tend to be sparse and come from small samples. To test for evolutionary changes in particular, sufficient sample breadth across multiple measurements is needed throughout a large enough timespan where climate data are available at both small and large intervals. The present dataset addresses these issues by examining skeletal remains that are predictive of relative body size in Homo over a period of roughly 700,000 years. Measures of femoral head breadth (mm), proximal tibia plateau breadth (mm), and stature/bi-iliac breadth (cm) of skeletal remains were used to produce 247 body mass (kg) estimates that span from present day to 700,000 years ago (700 kyr BP). Body mass data were compared to five climate records. Global climate change was derived from the ice core at EPICA Dome C, which provides precise surface temperature measurements dating back 809,950 years. Regional climate change was derived from sediment samples recovered from Lake Malawi in eastern Africa and two North Atlantic Ocean deep sea cores located roughly between North America, Africa, and Europe. Pollen sequences in the Burundi Highlands were used to determine precipitation levels and humidity levels were tested using a datasource derived from grain-size analyses of siliciclastic marine sediments from the coast of Mauritania. When comparing Homo body size and proportionality against the climate records, evolutionary body changes correspond to temperature but not precipitation or humidity.探究气候变化对古人类的影响所面临的核心挑战，在于缺乏可对比的样本数据。目前完整的古人类骨骼遗骸极为稀少，仅依靠破碎的骨骼残片难以准确估算其体型大小。现有可获取的测量数据往往极为零散，且样本量普遍偏小。若要专门检验演化变化，则需要在跨度足够大的时间范围内，获取多维度测量指标的充足样本广度，且该时间段内需有高精度、不同时间分辨率的气候数据支撑。 本数据集针对上述问题展开研究，选取了可反映人属（Homo）相对体型的骨骼遗骸，时间跨度约70万年。研究通过测量骨骼遗骸的股骨头宽度（mm）、胫骨近端平台宽度（mm）以及身高/髂骨间宽度（cm），共生成了247个体质量（kg）估算值，时间范围覆盖现代至70万年前（700 kyr BP）。 研究将体质量数据与五类气候记录进行对比。全球气候变化数据取自EPICA Dome C冰芯，该冰芯可提供距今809950年的高精度地表温度测量记录。区域气候变化数据则来自东非马拉维湖的沉积物样本，以及位于北美、非洲与欧洲之间的北大西洋两处深海岩芯。布隆迪高地的花粉序列被用于推断降水水平，而湿度水平则通过取自毛里塔尼亚海岸的硅质碎屑海洋沉积物粒度分析数据源进行测算。 将人属体型及体型比例与气候记录进行对比后发现，体质量的演化变化与地表温度显著相关，但与降水或湿度并无关联。