Thermoregulation in mice, rats and humans: An insight into the evolution of human hairlessness

TL;DR

This paper explores how thermoregulation influences the evolution of hairlessness in humans, rats, and mice, highlighting the balance between heat retention and dissipation in evolutionary adaptations.

Contribution

It provides an evolutionary perspective on hair loss in mammals based on thermoregulatory needs and body size changes.

Findings

Humans lost body hair as an adaptation to thermoregulation.

Rats lost tail hair to improve heat dissipation.

Thermoregulation influences mammalian size and hair distribution.

Abstract

The thermoregulation system in animals removes body heat in hot temperatures and retains body heat in cold temperatures. The better the animal removes heat, the worse the animal retains heat and visa versa. It is the balance between these two conflicting goals that determines the mammal's size, heart rate and amount of hair. The rat's loss of tail hair and human's loss of its body hair are responses to these conflicting thermoregulation needs as these animals evolved to larger size over time.