The Hypotheses Reevaluation Math
From the logic and math point of view, there are two alternatives and probabilities to consider P(H), P(~H), P(H)+P(~H)=1, namely: whether macroscopic life on Mars is present (H), or it is not (~H).
According to the Bayes’ theorem, every relevant observation A changes the probabilities ratio R=P(H)/P(~H) of these two hypotheses:
R|A = R*K(A), where K(A)=P(A|H)/P(A|~H)
For any two independent observations A, B, holds P(AB|H)=P(A|H)*P(B|H), so we have
Consequently the probabilities ratio after taking into account observations - is a product of initial a priory probabilities ratio estimate, and of the correction coefficients for all observations.
If we have enough observations, the initial bias of the hypothesis probability estimate does not really matter /if it is not zero/, since the corrections will eventually overcome it.
We will need more general rule based on the Bayes theorem:
with R(H)=P(H)/P(H0), R(H|A)=P(H|A)/P(H0|A), K(H|A)=P(A|H)/P(A|H0):
R(H|A)=R(H)* K(H|A), K(H|AB)=K(H|A)*K(H|B)
I(H|A)= -log(K(H|A)), I(H|AB)=I(H|A)+I(H|B)