I understand that elements heavier than hydrogen and helium require the life span of a solar system to be created through fusion. With a rough estimate of the universe's age of 13.8 B years and our system's rough age of 4.5 B years, how many generations of star formation and collapse do we believe were required to create the elements in our system? Also related, what percentage of this matter may have originated from a single system? Or in other words, is our system a homogeneous conglomeration of the ejecta from numerous systems or is it more likely that the bulk of the matter in our system came from a single ancestor system? It would seem to be too time consuming for several systems to cast their matter to the skies and have enough matter coalesce into a system to be several generations old. I know this is getting long and multi-pronged here but lastly, when our sun becomes a red giant and casts off roughly 2/3rds of it's mass, what is the likelihood that Jupiter or Saturn may collect enough mass to approach the minimum required to form a new star?