The Science of Survival

The Science of Survival — page 5
Humans have also developed some natural adaptations for living in challenging conditions For example scientists have found physical differences between populations that spend their lives at high altitudes and populations that spend their lives at sea level But most human adaptations are behavioral This type of adaptation includes making technologies that allow humans to do things they otherwise would not be able to do Behavioral adaptations allow humans to survive in some of the most difficult circumstances on Earth and beyond 8 IN THE REAL WORLD The Human Thermostat The thermostat for the human body is located in the brain Nerves in the skin send temperature information to the brain If areas are too cold or hot compared to the brain’s temperature messages are sent back to nerves and glands to adjust Too cold and a message causes muscles to shiver This creates heat Too hot and a message goes to the sweat glands to start perspiration When the sweat evaporates it cools the skin