Extrapolating human population to 5000 B.C. poses significant challenges due to the lack of reliable data and the influence of various factors like disease and technology. Some participants suggest using logistic models of population growth, which require an upper limit that can change with advancements. Discussions highlight that while population growth has been exponential, assumptions about zero population before 10,000 B.C. are debated, with some arguing for a gradual increase instead. The conversation also touches on the natural equilibrium of early human populations, comparing them to modern indigenous societies. Ultimately, the complexities of historical population dynamics make precise extrapolation difficult.