This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Science fiction suggests that life on other planets, if it exists, is likely far more advanced than life on Earth. A recent study suggests otherwise.
This new study, led by Chris Doughty, a professor of ecoinformatics at Northern Arizona University, proposes that the extent to which life on potentially habitable exoplanets in Earth's stellar neighbors is advanced is likely related to plant energy, not just how much time has passed. That means that, although Earth is young compared to some of its stellar neighbors, which are older by several billion years, life on exoplanets with worse conditions for cumulative photosynthesis likely evolved more slowly over billions of years. "Physicist Enrico Fermi famously asked, given the high likelihood of intelligent life in the galaxy, 'Where are they?'" Doughty said.
"This paper suggests that our exoplanet stellar neighborhood may be quiet because most Earth-like planets near us are likely to be evolutionarily behind us and still at the microbial stage. Which means we can sleep well, because if life on those exoplanets evolved just like on Earth, most of those planets will just be filled with microbes and not advanced aliens." The study was published Sept. 22 in the International Journal of Astrobiology. It doesn't say there isn't highly advanced extraterrestrial life that could lead to a real-life reenactment of "The Three-Body Problem." What the study says, according to the researchers, is that such a species nearby is unlikely, as cumulative photosynthesis on nearby potentially habitable exoplanets would be lower.
And here's why: If life ever evolved on a planet, its continued evolution wouldn't just automatically happen over time. Rather, it would be dependent on the cumulative plant energy of a planet, the study authors hypothesize. Looking at Earth, warm, wet places have more plant growth and species than cold, dry places.
Scientists believe this is because there is more plant growth and ecological space for animals to exist. Thus, a young, warm, wet exoplanet may have more evolutionary development than an older, colder, drier exoplanet. In their paper, Doughty and his co-authors explore the implications of this hypothesis for exoplanets.
The planets most likely to have life orbit red dwarfs, the most common star type in our galaxy. These planets, which are often billions of years older than Earth, have dimmer light and are often tidally locked, meaning only one side of the planet faces its sun. "If photosynthetic life evolved on these planets, that life has been photosynthesizing for potentially billions of years longer than on Earth," said co-author Michael Gowanlock, an associate professor of informatics at NAU.
Extract — continue reading at the source.
