Terms to know:  speciation, vicariance event, dispersal event, biogeography, phylogeography

Questions:

1. An unanswered question in evolutionary biology is whether most allopatric speciation has occurred through vicariance events or through dispersal events.  Explain how studying phylogenies can help us to answer this question; be specific: state what the different hypotheses of speciation predict with regard to phylogenies.
2. Explain why the phylogenetic history of a group of species may show the same pattern as the geological history of the area in which the species live.  What kind of speciation has been occurring (be specific) if this has been the case?
3. With regard to biogeography, what can we learn from studying phylogenies of several unrelated groups rather than just studying the phylogeny of one group?
4. The phylogenies given below are for 4 different monophyletic groups of birds that have the same geographic range in the Amazon basin in South America.  Locations as well as specific names are given.  What do they suggest about geological events that may have affected speciation?
5. The large flightless birds (ostriches & their relatives) have the following geographic ranges: Ostriches -- Africa.  Emus & Cassowaries -- Australia.  Rheas -- South America.  It is hypothesized that speciation events between the main groups occurred through allopatric speciation as a result of continental drift.  According to geological evidence, the southern continents split apart from one another in the following order: (1) Australia separated from the other continents.  (2)  Africa and S. America drifted apart.  Draw a possible phylogeny of the large flightless birds that would support the hypothesis that speciation was related to continental drift.  Now draw a phylogeny of the large flightless birds that would NOT support this hypothesis.
6. The following phylogenies represent several groups of hypothetical invertebrate in Hawaii.  They live in areas that are separated from one another by lava flows from volcanic eruptions that have occurred several times in the past. [Note -- while the invertebrates are obviously made up, this process of lava flow from volcanic eruption separating species into different groups is thought to be a major factor in Hawaiian biogeography].   What do the phylogenies presented suggest about: (a) which areas were separated by lava flows earlier and which later? (b) which speciation events occurred because the range of the invertebrates was interrupted by a lava flow, and which speciation events occurred because invertebrates dispersed from one area to another.