How did climate change around 7500 bce affect Middle American food gathering?

Around 7500 BCE, the climate in Middle America underwent a significant shift characterized by increased dryness and a change in fauna following the retreat of glaciers from the last Wisconsin substage.1

This environmental transformation fundamentally altered the subsistence strategies of the region's inhabitants. As the large herd animals (megafauna) that had previously been hunted became extinct or scarce, the people were forced to transition away from big-game hunting. Instead, they shifted their focus toward new means of survival, specifically the hunting of small game and the systematic collecting of wild food plants.1

This period marked the beginning of a transition toward more diverse foraging practices, which eventually laid the groundwork for the development of agriculture in the region. Archaeological evidence from sites such as the Tehuacán Valley in Puebla, Mexico, illustrates this shift, showing that these groups became seasonal nomads who utilized temporary camps as bases for gathering wild resources like grasses, maguey, and cactus fruits. This adaptation was a crucial step in the evolution of Middle American Mesoamerican civilization, leading eventually to the domestication of crops such as squash, corn, and beans.12