Other than humans, today’s smartest primates—chimpanzees, bonobos, gorillas, and orangutans—have a combined wild population of approximately 400,000 to 700,000. This number persists despite their near-complete inability to expand beyond their current ideal environments, a restriction not faced by any human species since before Homo habilis. Moreover, this is in spite of the extreme pressures exerted by various human species over the last 300,000 years. Drawing from this, the hominins of 700,000 BCE, including Homo erectus, Homo heidelbergensis, and other yet-to-be-discovered human species, might have had a global population ranging from 1.2 to 2.1 million. While highly speculative, this estimate is plausible, perhaps even conservative, considering Homo erectus‘ widespread presence and success across diverse environments in Africa and Eurasia. This era, significantly before the emergence of modern humans, showcases a dynamic tableau of early human life, marked by significant migrations and adaptations to varying ecological niches. Check out A New Look at Ancient Hominin Numbers: A Speculative Journey for more information.