Human-Like Lifeforms Beyond Earth? New Study Says It's More Likely Than We Thought

A groundbreaking study has suggested that intelligent life may be a common outcome on planets, rather than a rare occurrence, potentially increasing the likelihood of human-like civilisations existing elsewhere in the universe. Researchers from Penn State University have challenged the traditional "hard steps" theory, proposing that the emergence of intelligent life, similar to humanity, could be a natural consequence of a planet's evolution.

"This new perspective suggests that the emergence of intelligent life might not be such a long shot after all. Instead of a series of improbable events, evolution may be more of a predictable process, unfolding as global conditions allow. Our framework applies not only to Earth but also to the planets, increasing the possibility that life similar to ours could exist elsewhere," said the paper's co-author Jason Wright.

The study published in the journal Science Advances challenges the long-standing "hard steps" theory, proposed by physicist Brandon Carter in 1983. This traditional model suggests that the evolution of complex, intelligent life is a highly improbable event, resulting from a series of rare occurrences. As a result, it implies that intelligent civilizations are unlikely to exist elsewhere in the universe. However, the new research presents a contrasting view. Their model proposes that the emergence of humanity on Earth was not as improbable as previously thought, potentially increasing the likelihood of intelligent life existing on other planets.

"We are arguing that intelligent life may not require a series of lucky breaks to exist. Humans didn't evolve 'early' or 'late' in Earth's history, but 'on time,' when the conditions were in place. Perhaps it's only a matter of time, and maybe other planets can achieve these conditions more rapidly than Earth did, while other planets might take even longer", said Dan Mills, the paper's lead author.

The study proposes that significant evolutionary milestones were the result of predictable and logical events, rather than random chance. For example, the emergence of photosynthesis in plant life led to an oxygen-rich atmosphere, paving the way for the expansion of animal life on Earth.

In contrast to Brandon Carter's theory, which suggests that complex life arose from a unique combination of favourable conditions, the new research implies that the development of life on Earth was a natural consequence of the planet's evolution. The study introduces the concept of "windows of habitability," suggesting that planets like Earth may inherently pass through stages that support the emergence of complex life.

Notably, the researchers challenge Carter's assumptions, which were based on the Sun's lifespan. By reevaluating this aspect, the new study offers a fresh perspective on the likelihood of intelligent life existing elsewhere in the universe.