Questions for Lab 3
It is not necessary to look at supplementary material for these papers. You do not
need to worry about the details of the phylogenetic/dating analyses to get the main
point of these papers, but keep in mind that max/min age estimates of fossils are
used as calibrations to adjust dating estimates of speciation events on the
phylogenies.
2003 Paper:
1. Explain the major differences between the models shown in Figure 1.
2. Why do you suppose the authors used 19 nuclear genes, but only three mitochondrial
genes to reconstruct their phylogeny of mammals?
3. Are the results shown in Figure 2 consistent with one of the hyptheses from the
introduction? If so, which one and why?
4. Why does it make sense for Chiroptera to have undergone an explosive adaptive
radiation right at the K-T boundary?
2007 Paper:
1. What is “r” and how can it provide information about whether dinosaurs were
preventing an adaptive radiation of mammals before the K-T extinction event? What did
the r plots in Fig. 2 show?
2. Does this paper suggest the events surrounding the K-T boundary had a major or
minor influence on the majority of mammalian adaptive radiation?
3. What are some of the other major Earth history changes that might correspond to the
appearance of the major Orders of Mammals before the K-T boundary?
4. Explain what the authors mean by a “phylogenetic fuse”. Does this study show that
phylogenetic fuses are longer, shorter, or the same as previous studies?