Pearson Alannah, Bruner Emiliano, Polly P David
School of Archaeology and Anthropology, The Australian National University, Canberra, Australia.
Paleoneurobiology of Hominins, Centro Nacional de Investigación sobre la Evolución Humana, Burgos, Spain.
Am J Biol Anthropol. 2023 Apr;180(4):768-776. doi: 10.1002/ajpa.24712. Epub 2023 Feb 15.
Two decades ago, Rilling and Seligman, hereafter abbreviated to RAS Study, suggested modern humans had relatively larger temporal lobes for brain size compared to other anthropoids. Despite many subsequent studies drawing conclusions about the evolutionary implications for the emergence of unique cerebral specializations in Homo sapiens, no re-assessment has occurred using updated methodologies.
We reassessed the association between right temporal lobe volume (TLV) and right hemisphere volume (HV) in the anthropoid brain. In a sample compiled de novo by us, T1-weighted in vivo Magnetic Resonance Imaging (MRI) scans of 11 extant anthropoid species were calculated by-voxel from the MRI and the raw data from RAS Study directly compared to our sample. Phylogenetic Generalized Least-Squares (PGLS) regression and trait-mapping using Blomberg's K (kappa) tested the correlation between HV and TLV accounting for anthropoid phylogeny, while bootstrapped PGLS regressions tested difference in slopes and intercepts between monkey and ape subsamples.
PGLS regressions indicated statistically significant correlations (r < 0.99; p ≤ 0.0001) between TLV and HV with moderate influence from phylogeny (K ≤ 0.42). Bootstrapped PGLS regression did not show statistically significant differences in slopes between monkeys and apes but did for intercepts. In our sample, human TLV was not larger than expected for anthropoids.
Updated imaging, increased sample size and advanced statistical analyses did not find statistically significant results that modern humans possessed a disproportionately large temporal lobe volume compared to the general anthropoid trend. This has important implications for human and non-human primate brain evolution.
二十年前，里林和塞利格曼（以下简称RAS研究）指出，与其他类人猿相比，现代人类的颞叶相对于脑容量而言相对较大。尽管随后有许多研究得出了关于智人独特大脑特化出现的进化意义的结论，但尚未使用更新的方法进行重新评估。
我们重新评估了类人猿大脑中右侧颞叶体积（TLV）与右侧半球体积（HV）之间的关联。在我们重新编制的样本中，通过体素计算了11种现存类人猿物种的T1加权活体磁共振成像（MRI）扫描数据，并将RAS研究的原始数据与我们的样本直接进行比较。系统发育广义最小二乘法（PGLS）回归和使用布隆伯格K值（kappa）的性状映射检验了考虑类人猿系统发育情况下HV与TLV之间的相关性，而自抽样PGLS回归检验了猴子和猿类子样本之间斜率和截距的差异。
PGLS回归表明TLV与HV之间存在统计学上的显著相关性（r < 0.99；p ≤ 0.0001），系统发育有一定影响（K ≤ 0.42）。自抽样PGLS回归未显示猴子和猿类之间斜率有统计学上的显著差异，但截距有差异。在我们的样本中，人类的TLV并不比类人猿预期的大。
更新的成像技术、增加的样本量和先进的统计分析并未发现有统计学显著结果表明现代人类与一般类人猿趋势相比拥有不成比例的大颞叶体积。这对人类和非人类灵长类动物的大脑进化具有重要意义。
