An international study has shown that the probability of intelligent life emerging on Earth-like planets is low, although primitive organisms may be much more common.
According to the journal Proceedings of the National Academy of Sciences, scientists have constructed a probabilistic model that takes into account the course of Earth’s evolution. The analysis showed that the emergence of intelligent life is a complex and rare process: the chances of a civilisation similar to ours developing on a twin Earth are approximately 3:2. At the same time, the probability of primitive microorganisms appearing is estimated to be extremely high — about 9:1.
The author of the study, astronomer David Kipping from Columbia University, used Bayesian analysis and took into account three key factors: the time of the appearance of the first living organisms, the time of the emergence of intelligent life, and the size of the planet’s habitability window. According to him, life on Earth originated quite early — microorganisms existed just 400 million years after the planet’s formation. Intelligent life, on the other hand, has only emerged in the last few million years, making its appearance a relatively rare event.
Kipping emphasised that his work does not prove the existence of life beyond Earth, but only provides a statistical assessment of the processes that took place on our planet. The results of the study help astronomers identify the most promising candidates for the search for extraterrestrial civilisations.