Although the repetition in nature of the cycles of the moon or the sun can yield the concept of a clock based on intervals and recursion, it does not yield the concept of irretrievable aging. And neither natural repetition nor mere biological aging yields the concept of the irretrievable passage of linear time. First one is, say, a son, then a father, then a grandfather, and so on ever backward. This is genealogy, and not simply biology, for although biological transformation can yield the concept of age, yet it does not indicate a succession of linear ages. And though natural cycles can indicate change and recursion, yet we have no understanding that today's Spring is the chronological descendent of last Spring, no unification of time as a series of sequential generations, except by reference to a genealogical tree.
Genealogy connects past, present, and future into one.
It connects ancestors in the past to real descendents in the present and potential descendents in the future, binds them into one living unit. Many of the seemingly intuitive aspects of kinship as conceptual metaphor can be precisely understood by reference to the synthetic theory of evolution, to genetics. If one thinks in terms of the descent of genes or genotypes rather than persons, then descendents are quite literally partial physical copies of ancestors. There are specific genetic mechanisms in the stages of transmission for variation and similarity. The individual embodies his ancestors concretely.