(Quick Quiz Questions)
Gu, Z, L.M. Steinmetz, X. Gun., C. Scharfe, R. Davis, and W-H Li. 2003. Role of duplicate genes in genetic robustness against null mutations. Nature 421:63-66.
1. The availability of whole genome sequences has radically altered our ability to test evolutionary hypotheses about the evolutionary role of genomic change, such as duplication events. In general, duplication events are proving to be much more common than previously thought. This is has led to much discussion over fitness advantages conferred by duplication. Some have hypothesized that duplication promotes evolutionary diversification because one copy of the gene can retain its function while the other copy accumulates mutations that ultimately lead to novel functions. In this view, the evolutionary significance of duplication events is the the evolutionary novelty that it confers. This paper offers an alternative hypothesis. What is it?
2. Draw a hypothetical graph like Fig. 1a would support the previous conclusion of Wagner 2000 about the relationship between duplication and robustness (second full paragraph of the paper and citation #10).
3. What were the four specific hypotheses that were tested in this paper?
4. What evidence suggests that duplication is not the only factor that contributes to robustness against null mutations? What other factors might be involved?
5. Are the hypotheses described in Question 1 (above) and those supported in this paper mutually exclusive? Why or why not?