The new research described in this book demonstrates that the interplay of a host of founding conditions can frequently produce profound differences in population expansion rates and maintenance of genetic diversity in contrasting populations that differ, often only to slight degrees, in initial founding conditions. The goals of this book are twofold. First, it serves as a user’s manual for the computer program NEWGARDEN (provided) designed to enable investigations, using computer generated populations, of population growth and genetic variation resulting from user-specified differences in initial founding conditions. Second, the book provides a series differences in geometric spacing among plant founders, can result in significant differences in demographic and genetic variation trajectories for the ensuring populations.