Does Gaia Play Dice? Simple Models of Non-Darwinian Selection

Area of Science:

• Astrobiology
• Planetary Science
• Statistical Modeling

Background:

• Planetary habitability is a complex field with various proposed selection mechanisms.
• Realistic models often obscure the specific effects of these mechanisms.
• Analytically tractable models are needed to isolate and study individual mechanisms.

Purpose of the Study:

• To explore proposed planetary habitability selection mechanisms using simple, analytically tractable models.
• To isolate the consequences of specific selection mechanisms from confounding factors.
• To investigate the implications for concepts like the Inhabitance Paradox and Gaian bottleneck.

Main Methods:

• Development of simple models based on rolling dice.
• Analysis of observable outcomes (face value of the die) over time.
• Comparison of different selection models: Selection by Survival, Sequential Selection, and Sequential Selection with Memory.

Main Results:

• The observable 'improves' over time in all models.
• Improvement in Selection by Survival and Sequential Selection is attributed to sampling effects.
• Sequential Selection with Memory indicates a statistical tendency for systems to improve.

Conclusions:

• Simple models can effectively isolate and study the effects of planetary habitability selection mechanisms.
• Sampling effects play a significant role in observed improvements in some models.
• The concept of 'improvement' over time in planetary systems has statistical underpinnings relevant to astrobiological paradoxes.