# The fitness costs and benefits of hunter-gatherer locomotor engagement

## TL;DR

The paper explores how different types of movement, like walking and climbing, affect survival and success in hunter-gatherer societies.

## Contribution

It reveals that movement benefits and costs go beyond energy use to include social status and injury risks.

## Key findings

- Locomotion fitness factors include status, protection, and injury risks, not just energy.
- Energetics dominate bipedal costs, while climbing risks like falls are more significant.
- Findings impact debates on human evolution and hunter-gatherer behavior.

## Abstract

Bipedalism is a distinguishing feature of our species and, as such, there has been much interest in the energetic costs and foraging returns of walking and running, especially among hunter-gatherer societies. However, humans routinely exhibit extensive locomotor versatility, with hunter-gatherers consistently also swimming, diving, and climbing. Additionally, the fitness costs and benefits of locomotion extend well beyond energy income and expenditure. Here, we review evidence from over 900 ethnographic documents across a worldwide sample of more than 50 hunter-gatherer societies to examine the fitness costs and benefits of walking, running, climbing, swimming, and diving. We show that the fitness costs and benefits of locomotor engagement consistently extend well beyond energetics to include, for example, currencies of status, protection from hazards, and risks of injury or death. These fitness factors differ in significance between locomotor modalities, with implications for the comparison of bipedal and non-bipedal locomotion. For example, while energetic demands represent the major cost of most bipedal engagements, the fitness implications of potential fall injuries may outweigh those of energetics in tree climbing. These results inform existing debates relating to hominin locomotor evolution and hunter-gatherer behavioural ecology.