A potential survival strategy during the late heavy bombardment

Abstract

The Late Heavy Bombardment (LHB) represents a period of time in which an increased number of impactors collided with the Earth. While there were continuous collisions of impactors globally, these would be perceived by populations of life as locally infrequent, as they occurred at different times and locations across the planet. These impactions presented a severe and unpredictable environmental pressure on life, as they could at any moment destroy organisms and their local habitats. However, such an environment could potentially lead to the selection of a particular evolutionary strategy, bet hedging, which is an adaptation to unpredictability itself. Thus, a model for analysing this has been put forward in the form of a system of rings arising from an impact-consisting of the inner primary and outer secondary rings, which demonstrates the dynamic interplay between the external pressure from impact dynamics and life's evolutionary response towards it. The model demonstrates that there is a longer relaxed period where organisms thrive and a short violent period where they must survive three violent events and respond to a potentially different environment. This evolutionary strategy consistently results in a higher number of surviving organisms compared to other evolutionary strategies; thus, it may have played a crucial role in life's endurance through the LHB-an insight relevant to astrobiology.