Final answer:
The exact population size of Homo sapiens during their migration from Africa is unknown, but they began moving out around 100,000 years ago in small nomadic groups and achieved global dispersal despite relatively slow population growth.
Step-by-step explanation:
The estimated population size of Homo sapiens when we migrated from Africa is not precisely known, but we do know that modern humans, Homo sapiens, emerged in Africa around 200,000 years ago. Small groups of nomadic hunters and gatherers from these populations began venturing out of Africa as early as 100,000 years ago, according to archaeological evidence. Over tens of thousands of years, these early humans spread across Europe, Asia, and Australia, and by 10,000 years ago, they had reached the Americas.
During this period of early migration and population expansion, Homo sapiens lived in small, mobile groups that followed herds and resources, adapting to a variety of environments. Birth and death rates were comparatively high, which meant that despite the migration and spread of our species, the overall population growth was relatively slow. The exact numbers are hard to estimate, but it is believed that the migrating populations were small. Eventually, Homo sapiens became the only human species to survive, spreading globally.