美国德克萨斯大学Kappelman, John及其课题组的最新研究揭示了Toba火山超级喷发期间非洲之角的适应性觅食行为。相关论文于2024年3月20日发表在《自然》杂志上。

研究人员报道了一个考古遗址（位于埃塞俄比亚西北部低地的shinfa-metema），其中最年轻的Toba火山凝灰岩cryptotephra沉积可以追溯到大约7.4万年前，该沉积为人们可能使用弓箭在河边进行觅食（包括各种陆生和水生动物）提供了早期和罕见的证据。哺乳动物牙齿化石和鸵鸟蛋壳化石的稳定氧同位素表明，该遗址处于高度季节性干旱时期。

异常丰富的鱼类表明，在漫长的旱季，捕获发生在季节性河流的更小、更浅的水坑中，揭示了中石器时代对挑战性气候条件的灵活适应。沿着旱季水坑的适应性觅食将把季节性河流变成“蓝色公路”走廊，这可能有助于非洲以外的扩散，并表明这一事件并不局限于潮湿的气候时期。一般来说，在季节性干旱条件下生存所需的行为灵活性，尤其是Toba火山超级喷发的明显短期影响，可能是现代人类最近的分散和随后的全球扩张的关键。

据了解，尽管现代人在10万年前多次离开非洲，但那些非洲人的祖先在不到10万年前就分散了。大多数模型认为，这些事件是通过潮湿时期形成的绿色走廊发生的，因为干旱期限制了人口的流动。

附：英文原文

Title: Adaptive foraging behaviours in the Horn of Africa during Toba supereruption

Author: Kappelman, John, Todd, Lawrence C., Davis, Christopher A., Cerling, Thure E., Feseha, Mulugeta, Getahun, Abebe, Johnsen, Racheal, Kay, Marvin, Kocurek, Gary A., Nachman, Brett A., Negash, Agazi, Negash, Tewabe, OBrien, Kaedan, Pante, Michael, Ren, Minghua, Smith, Eugene I., Tabor, Neil J., Tewabe, Dereje, Wang, Hong, Yang, Deming, Yirga, Solomon, Crowell, Jordan W., Fanuka, Matthew F., Habtie, Teshager, Hirniak, Jayde N., Klehm, Carla, Loewen, Natalia D., Melaku, Sahleselasie, Melton, Sierra M., Myers, Timothy S., Millonig, Sarah, Plummer, Megan C., Riordan, Keenan J., Rosenau, Nicholas A., Skinner, Anne, Thompson, Abraham K., Trombetta, Lindsey M., Witzel, Adrienne, Assefa, Ephrem, Bodansky, Maria, Desta, Ayenachew A., Campisano, Christopher J., Dalmas, Daniel, Elliott, Connor, Endalamaw, Metasebia, Ford, Nicholas J., Foster, Frederick, Getachew, Tomas, Haney, Yibai Li, Ingram, Brittney H., Jackson, Jonayah, Marean, Curtis W., Mattox, Sissi, de la Cruz Medina, Karla, Mulubrhan, Gebretsadkan, Porter, Keri, Roberts, Alexis, Santillan, Perla, Sollenberger, Alaric, Sponholtz, Julia, Valdes, Jessica, Wyman, Lani, Yadeta, Meklit, Yanny, Sierra

Issue&Volume: 2024-03-20

Abstract: Although modern humans left Africa multiple times over 100,000 years ago, those broadly ancestral to non-Africans dispersed less than 100,000 years ago1. Most models hold that these events occurred through green corridors created during humid periods because arid intervals constrained population movements. Here we report an archaeological site—Shinfa-Metema, in the lowlands of northwest Ethiopia, with Youngest Toba Tuff cryptotephra dated to around 74,000 years ago—that provides early and rare evidence of intensive riverine-based foraging aided by the likely adoption of the bow and arrow. The diet included a wide range of terrestrial and aquatic animals. Stable oxygen isotopes from fossil mammal teeth and ostrich eggshell show that the site was occupied during a period of high seasonal aridity. The unusual abundance of fish suggests that capture occurred in the ever smaller and shallower waterholes of a seasonal river during a long dry season, revealing flexible adaptations to challenging climatic conditions during the Middle Stone Age. Adaptive foraging along dry-season waterholes would have transformed seasonal rivers into ‘blue highway’ corridors, potentially facilitating an out-of-Africa dispersal and suggesting that the event was not restricted to times of humid climates. The behavioural flexibility required to survive seasonally arid conditions in general, and the apparent short-term effects of the Toba supereruption in particular were probably key to the most recent dispersal and subsequent worldwide expansion of modern humans.

DOI: 10.1038/s41586-024-07208-3

Source: https://www.nature.com/articles/s41586-024-07208-3