Evo Final Exam Practice Questions 2024 (PDF)

1. The phylogeny below shows the relationship among some species of ascomycete fungi, including the model organism Saccharomyces cerevisiae used by our very own Stephan Zweifel (among many other biologists). This phylogeny was based on amino acid sequences of 1,070 different proteins from each of th...

1. The phylogeny below shows the relationship among some species of ascomycete fungi, including the model organism Saccharomyces cerevisiae used by our very own Stephan Zweifel (among many other biologists). This phylogeny was based on amino acid sequences of 1,070 different proteins from each of these species. In answering the following questions, assume that the phylogeny is correct. a) Circle each genus (Kluyveromyces, Saccharomyces, Eremothecium, etc.) on the phylogeny that is monophyletic. b) Suppose you were assigned the task of renaming these species so that all genera were in fact monophyletic. Propose a classification that would maintain at least the three genera Kluyveromyces, Saccharomyces, and Candida. Choose a solution that minimizes the number of names that must change. c) Under your renaming, will Stephan have to change the name of the organism he works on? d) Based on this figure, would rate of amino acid change in this set of fungi be a useful molecular clock? Why or why not? The yeast species phylogeny recovered from concatenation analysis of 1,070 genes using maximum likelihood. Asterisks denote internodes that received 100% bootstrap support by the concatenation analysis. Values near internodes correspond to gene-support frequency and internode certainty, respectively. The scale bar is in units of amino-acid substitutions per site. Modified figure 1 from: Salichos, L., and A. Rokas. 2013. Inferring ancient divergences requires genes with strong phylogenetic signals. Nature 497:327-331. 2. Hamilton predicted that altruism could evolve if relatives are the recipients of the altruistic act. However, altruism may not be equally likely in all members of a population. In particular, consider a long-lived bird that is capable of reproduction over many years. This bird could act altruistically to protect its relatives from predators, even though this is done at the risk of being killed itself. Why might this altruistic behavior be more likely to evolve when expressed in an older bird compared to a bird just reaching reproductive age for the first time? 3. In wattled jacanas (Jacana jacana), only the males make nests, incubate eggs, and care for newly hatched chicks. a) Female jacanas have been observed to be highly competitive in their search for males. Why might this follow from sexual selection theory? b) When a female does take over a male that has eggs in his nest from a previous female, she will destroy the eggs in the nest. Why could such behavior be adaptive? 4. It is often stated that the diversification of placental mammals was possible only after the catastrophic extinction of non-avian dinosaurs. State one specific type of evidence that contradicts this viewpoint. Explain briefly.