Note that Equation 6 and Equation 3 are just ... usually in the context of the growth of the human population. Malthus talked quite a lot about what in fact limits population growth.

While studying how resource availability might affect human population growth, Verhulst published an equation that limits exponential growth as the size of the population increases. Verhulst's ...

We're in the midst of the Earth’s sixth mass extinction crisis. Harvard biologist E. O. Wilson estimated that 30,000 species per year (or three species per hour) are being driven to extinction.