Dan Zhu's research team from the School of Urban and Environmental Sciences published a paper revealing how the hunter-gatherer population density is constrained by the ecological environment

As a species, how did humans feed themselves and reproduce to this day? Starting from hunting-gathering, the simplest means of livelihood, it may be possible to gain insight into the lowest-level relationship between humans and the natural environment for millions of years

Hunting-gathering is the longest-lived mode of production in human history

Hunter-gatherers obtain food directly from wild animals and plants, so their population is closely related to local climate and ecosystem parameters

In order to explore the quantitative mechanism through which the ecosystem affects population density, the Zhu Dan research team of the School of Urban and Environmental Sciences of Peking University constructed the first global vegetation-animal-human (hunter-gatherer) phase based on the existing land surface process model.

Figure 1 The global vegetation-animal-human (hunter-gatherer) coupling model based on the ORCHIDEE land surface process model

This process-based mechanism model emerges an important rule: In areas with long non-growing seasons (winter or dry seasons), hunter-gatherers are highly dependent on the harvest of edible plants due to the seasonal scarcity of edible plants.

Figure 2 The ecosystem-human coupling model reveals that the increase in the proportion of meat in the diet (determined by the seasonal relative abundance of animal and plant resources) significantly reduces the population density that can be supported by a unit of NPP

Next, the research team plans to apply the model to the past nearly 200,000 years to explore how paleo-climate changes and ecosystem evolution affect the population dynamics and migration of ancient humans, and how human foraging, hunting, and expansion have adversely affected ecosystems.

The research result was titled " Global hunter-gatherer population densities constrained by influence of seasonality on diet composition " and was published online in Nature Ecology & Evolution ("Nature? Ecology and Evolution") on September 9, 2021