[s1artibartfast]

I guess I agree that discovering extinct life is information about probabilistic filters in earths future. I But, it does have to be weighed against the newly observed data supporting filters humans have already past.

To take your example, as we keep finding rodent fossils, we become more confident that a filter exists between rat and rocket-men. As we go from 0 planets with rodent fossils to 1 trillion planets, the probability that this is the filter keeps going up.

That is to say, we are not only decreasing the chance of pre-rat filters, but simultaneously increasing the chance that the filter is in the rat stage.