PHYLOGENIES & TREE-THINKING

摘要

While few state standards explicitly require knowledge of phylogenetics, most require some knowledge of evolutionary biology and many scientists and educators would hold that it is impossible to really understand evolution without an ability to accurately interpret phylogenetic trees (O'Hara, 1988, 1997). The next question is to consider what happens when populations become genetically isolated from one another for a long period of time, for example because of dispersal of a few individuals to a new, isolated region (e.g., an island), or the splitting of a formerly contiguous range by geological or climatic events (e.g., when mountains, rivers, or barriers of inhospitable environments arise).