Over the past 13,500 years, humans in what is now America were subjected to dramatic climate changes: an ice age ended, rain increased, and vegetation changed completely. Now archaeologists say these peoples evolved new technologies to deal with it.

A study published yesterday in the Proceedings of the National Academy of Sciences details the research of archaeologists who tracked changes in both the ecosystem and human culture during several different eras of climate change in North America. They looked at the remains of human cultures, from fires to farms and tools. And they looked at the remains of flora and fauna, determining which kinds of plants and animals would have served as food sources for humans at different points. Finally, they mapped these discoveries to what we know about climate change in the northern United States during the early human settlement of the region, just after ice sheets began melting away from what are now the northern midwest states.

According to a release about the study:

Samuel E. Munoz and colleagues analyzed environmental and archaeological data from a number of sites throughout the northeastern United States that were first settled by prehistoric people nearly 13,500 years ago. The authors combined radiocarbon dates from archaeological sites with ecological and climate records from lake sediments, and found that past climatic changes altered forest composition. For example, whereas sedge and pine trees dominated during the early years of the region's archaeological timeline, chestnut and spruce trees flourished during the later years. Furthermore, the ecological changes coincided with changes in both the population size and food-procuring strategies of prehistoric people. The findings suggest that environmental change likely influenced the population size and hunter-gatherer culture of prehistoric people in the northeastern United States.

Essentially, these changes sparked the creation of new technologies, particularly when old kinds of food became unavailable. One shift in the environment actually led to the development of maize farming, for example. Write the authors of the study, "changes in forest composition altered the distribution, availability, and predictability of food resources which triggered technological adjustments manifested in the archaeological record." In other words, changes in the environment reliably lead to a cascade effect that changes both the population size and human technological development.


Since we are undergoing another bout of climate change right now, this study begs the question: What kinds of technologies will we develop to deal with the outcome? And how will our population size change?

via PNAS