
Science Advances, Journal Year: 2025, Volume and Issue: 11(7)
Published: Feb. 14, 2025
According to the “hard-steps” model, origin of humanity required “successful passage through a number intermediate steps” (so-called “hard steps”) that were intrinsically improbable in time available for biological evolution on Earth. This model similarly predicts technological life analogous human Earth is “exceedingly rare” Universe. Here, we critically reevaluate core assumptions hard-steps lens historical geobiology. Specifically, propose an alternative where there are no hard steps, and evolutionary singularities origins can be explained via mechanisms outside intrinsic improbability. Furthermore, if Earth’s surface environment was initially inhospitable not only life, but also certain key steps existence, then timing controlled by sequential opening new global environmental windows habitability over history.
Language: Английский