It is not an approach to classification that uses shared, derived character states. This approach is called parsimony. See web page for this lecture. The reproductive isolation of populations is most important in the formation of a new species. Species may be defined as groups of actually or potentially interbreeding populations that are reproductively isolated from one another.
New species can also arise in the same geographic area.
Prairies formed in Illinois approximately 8,300 years ago. See page 63 in class notes. A syconium is an inflorescence of unisexual flowers. The flowers are not perfect and they do not possess a perianth that is attractive to insects. A syconium is a fig and we studied that in this week's lab.