Examination of the Adaptive Habitability Concept in Search for Habitable Exoplanets

Itay Weintraub

Technion

On the search for life on other worlds, the most agreeable observation methods will attempt to find evidence for water or other organic compounds in exoplanetary atmospheres. That is despite theoretical astrobiology holds much more suggestions for life, and even though the ancient life on earth did not even utilize oxygen as we do.

Taking into account that life on earth emerged on different terms than today and then adapted to change, the same can be applied on exoplanetary habitats.

This idea, termed here as "Adaptive Habitability", is demonstrated in this work through a planetary-level ecological-evolutionary model, with a single outer constraint which is the mean surface temperature of the planet.

First only a highly simplistic model is showing the relation between genetic adaptation features and the change in environmental temperature.

Then, certain simplifications are relaxed to include multiple spatial niches, geographical migration, multiple initial species and temperature dependent competition. A simple step function climate change is applied, then periodic change in time, and lastly - a more realistic constraint from a Kozai-Lidov oscillatory solar system.

It is shown that life have an extinction-survival limit on the genetic change rate and environmental tolerance, which is correlative to the external temperature change rate.