Estimating survival probability using the terrestrial extinction history for the search for extraterrestrial life.

Several exoplanets have been discovered to date, and the next step is the search for extraterrestrial life. However, it is difficult to estimate the number of life-bearing exoplanets because our only template is based on life on Earth. In this paper, a new approach is introduced to estimate the probability that life on Earth has survived from birth to the present based on its terrestrial extinction history. A histogram of the extinction intensity during the Phanerozoic Eon is modeled effectively with a log-normal function, supporting the idea that terrestrial extinction is a random multiplicative process. Assuming that the fitted function is a probability density function of extinction intensity per unit time, the estimated survival probability of life on Earth is [Formula: see text] from the beginning of life to the present. This value can be a constraint on [Formula: see text] in the Drake equation, which contributes to estimating the number of life-bearing exoplanets.