The extinction of megafauna (here meaning mammoths and other large mammals from the end of the Cenozoic) is attributed to one of two things: climate change making their habitats unsuitable and/or human over-hunting. The opposite side of the coin is the impact the climate and extinctions had on humanity and on the beginning of agriculture.
Megafauna Subsistence
This analysis focuses on the Mexican region that would ultimately see the rise of the civilizations of the Maya, Toltecs and others. In the Pleistocene (12,000-10,000 years ago) Mexico was grassland and marsh. A kill site at Santa Isabel Itzapan contains eight mammoth skeletons which bear many cut marks consistent with butchering: even the skulls have been turned over and opened to access the brain, and the skeletons are thoroughly dismantled. However, while full advantage was taken of the kills, the relative rarity of them suggests that they may not have been the main staple of the paleo-Indians, but perhaps a seasonal boon.
Holocene Climate Change and Subsistence
By 8000 BCE, the climate had grown warmer and wetter with the retreat of the glaciers, and forests had overtaken grasslands. This would have been a difficult change for megafauna above a certain size since it restricted their mobility, which may have played a role in their decline. As a result, faunal remains at human sites include larger amounts of small fauna, such as deer and rabbits. It suggests that the extinction alone was not devastating to their ability to feed themselves.
They were of course partaking of the local plant life as well: archaeologists find it harder to quantify this from the inhabited caves from that era, since wild fruits would often have been eaten where they were picked, leaving little in the way of evidence at known campsites. However there was considerable variety in the Mesoamerican region, including prickly pears, wild onions, artichokes, acorns, and agave, among others.
Climate Change and Agriculture
By 7000 BCE Mesoamerica’s modern climate was beginning to take shape, with interspersed regions of aridity, with the travel times between the caves humans used for shelters and their food sources and hunting grounds grew longer and more arduous. There is evidence of fruit being dried and stored at cave sites, and as time went on, sedentary living may have become more practical. Increasing evidence of cultivation, from seeds and gourds which have been subject to artificial selection coincides with the drier climate. Squash seems to come first, perhaps for water-bearing gourds as well as for its edible seeds. Beans and corn follow, and the ‘three sisters’ are complete by 5000 BCE.
Conclusion
The decline of Mesoamerican Pleistocene hunter-gatherers and the rise of agriculture are events dictated in large part by climate. Climate change altered the ecology but later came to change the way people lived as well; a telling reminder to us moderns about how we regard the weather.
Sources:
Anthony T. Boldurian and John L. Cotter Clovis Revisited: New Perspectices on Paleoindian adaptations from Blackwater Draw, New Mexico. (Philadelphia: University Museum, Universiy of Pennsylvania 1991)
Hugh C. Cutler and Thomas W. Whitaker “Cucurbits from the Tehuacan Caves” in The Prehistory of the TehucanValley: Volume One: Environment and Subsistence, Douglas S. Byers ed. (Austin: University of Texas Press 1967)
Kent V. Flannery “The Research Problem” in Guila Naquitz Kent V. Flannery ed. (Ann Arbor: Academic Press Inc. 1986)
Kent V. Flannery “Vertebrate Fauna and Hunting Patterns” in The Prehistory of the TehucanValley: Volume One: Environment and Subsistence, Douglas S. Byers ed. (Austin: University of Texas Press 1967)
Kent V. Flannery “Wild Food Resources in the Mitla Caves” in Guila Naquitz Kent V. Flannery ed. (Ann Arbor: Academic Press Inc. 1986)
Luis Aveleyra A. de Anda “The Second Mammoth and Associated Artifacts at Santa Isabel Iztapan, Mexico” in American Antiquity Vol. 22, No. 1 (Washington: Society for American Archaeology July 1956
Susan Toby Evans Ancient Mexico and Central AmericaL: Archaeology and Culture History (Lodon: Thames and Hudson, 2004)
