calc_ranks_since_earliest_detectable_mrca_with

calc_ranks_since_earliest_detectable_mrca_with(focal: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen], other: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen], confidence_level: float = 0.95) → int | None

How many generations have elapsed since the first where common ancestry with other could be detected?

How many depositions have elapsed along focal’s lineage since the earliest possible rank a MRCA between focal and other could be reliably detected at?

Even if a true MRCA of focal and other exists, if it occured earlier than the rank calculated here it could not be reliably detected with sufficient confidence after accounting for the possibility of spurious differentia collisions. (Although subsequent spurious differentia collisions after the true MRCA of focal and other could lead to MRCA detection at such a rank.)

Returns None if insufficient common ranks exist between focal and other to ever conclude at the given confidence level the existance of any common ancestry between focal and other (even if all strata at common ranks had equivalent differentiae).