Scientists offer solution to Gaia hypothesis

July 2 (UPI) -- How has Earth maintained the stability necessary for the development and evolution of life over billions of years? It is a question that has perplexed scientists for decades.

The so-called Gaia hypothesis suggests some sort of interactive resonance between Earth's biological and inorganic processes has allowed life to survive climate change, volcanoes, meteors and other threats.

Until now, scientists have struggled to explain exactly how this resonance works, but researchers at the University of Exeter have offered a solution to the Gaia puzzle.

In a new paper, published this week in the journal Trends in Ecology and Evolution, scientists described a stabilizing phenomenon they call "sequential selection."

The phenomenon works similarly to natural selection. Biological changes that destabilize life-friendly conditions will naturally be short-lived, while shifts that encourage stability are more likely to persist and reinforce life-friendly conditions.

Prolonged periods of stability allow for more stabilizing traits to emerge as life evolves and diversifies. Scientists dubbed this process "selection by survival alone."

Sequential selection and selection by survival alone help explain how the planet has accumulated stabilizing processes over billions of years.

"The central problem with the original Gaia hypothesis was that evolution via natural selection cannot explain how the whole planet came to have stabilizing properties over geologic timescales," Exeter professor Tim Lenton said in a news release. "Instead, we show that at least two simpler mechanisms work together to give our planet with life self-stabilizing properties."

In addition to making sense of Earth's stability, the new research could help scientists estimate the kinds of extraterrestrial conditions that might allow for the emergence of complex life elsewhere in the cosmos.

The new findings don't prove Earth's stability is permanent. Increasingly, scientists are concerned with potential for anthropogenic climate change to undermine this stability. The latest research could help scientists better understand how humans can avoid permanently destabilizing the planet's climate.

"We can learn some lessons from Gaia on how to create a flourishing, sustainable, stable future for 9-11 billion people this century," Lenton said.