Exposure to Burn Injuries Played Key Role in Shaping Human Evolution

hubie writes:

Humans' exposure to high temperature burn injuries may have played an important role in our evolutionary development, shaping how our bodies heal, fight infection, and sometimes fail under extreme injury, according to new research:

For more than one million years, the control of fire has powered human success, from cooking and heating to technology and industry, driving genetic and cultural evolution and setting us apart from all other species. But this relationship has also exposed humans to high temperature injuries at a scale unmatched in the natural world.

Humans burn themselves - and survive burns - with a frequency likely much greater than any other animal. Most animals avoid fire completely, while in contrast, humans live alongside fire and most humans will experience minor burns throughout their lives.

A new study published in BioEssays, led by Imperial College London researchers, suggests that this increased exposure to burn injuries may have driven notable genetic adaptations which differentiated humans from other primates and mammals. This may also explain both beneficial and maladaptive responses to severe burn injury.

Burn injuries exist on a spectrum of severity, with most small injuries healing on their own while severe burns can lead to lifelong disability or death. Burns damage the skin, the body's main protective barrier against infection, sometimes over large areas of the body. The longer the skin is damaged, the greater the risk that bacteria can enter the body and cause overwhelming infection.

The researchers argue that natural selection would have favoured traits that helped humans survive small to moderate burns. These may include faster inflammation, faster wound closure (to prevent infection) and stronger pain signals.

However, while these traits are helpful for less severe injuries, they can become harmful for large burns, which may explain why modern humans can experience extreme inflammation, scarring, and organ failure from major burns.

Using comparative genomic data across primates, the researchers found examples of genes associated with burn injury responses which show signs of accelerated evolution in humans. These genes are involved in wound closure, inflammation and immune system response - likely helping to rapidly close wounds and fight infection; a major complication after burn injury, particularly before the widespread use of antibiotics.

Read more of this story at SoylentNews.