Geneticists and climate modelers at the University of Cambridge recently teamed up to develop a model that would accurately represent the state of the Earth and of human beings over the past 120,000 years. According to this model, even though Homo sapiens developed in Africa over 200,000 years ago, humans didn’t leave the continent until 70,000 years ago, and it took us another 55,000 years to reach all the other continents (excluding Antarctica). The overriding reason for the delay, according to the study published in the Proceedings of the National Academy of Sciences, was climate change.
What’s the Big Idea?
The study identified four major roadblocks that, when removed due to changes in weather and water levels, furthered human exploration of Earth. According to Rick Potts of the Smithsonian, “[I]t’s the first time anyone has been able to explore climate’s power to facilitate human expansion…[it] fills in many of the links that have only been assumed or guessed at.” Although there are some flaws — most notably a 10,000-year discrepancy between humans’ arrival in Europe and existing archeological evidence — the researchers argue that the overall model demonstrates humanity’s continued dependence on climate.