Something like a stable balance between human numbers and resources may then begin to define itself.

In any effort to understand what lies ahead, as much as what lies behind, the role of infectious disease cannot properly be left out of consideration. Ingenuity, knowledge, and organization alter but cannot cancel humanity's vulnerability to invasion by parasitic forms of life. Infectious disease which antedated the emergence of humankind will last as long as humanity itself, and will surely remain, as it has been hitherto, one of the fundamental parameters and determinants of human history.

...the galloping increase of human numbers practically guarantees that existing margins between food supplies and human hunger will swiftly disappear, leaving less and less in reserve for times of unusual crisis.

...if human numbers increase, the rate of infection also increases.