Question

need help on D, E, F

6. Coronaviruses are common viruses found in bats and humans (and others). Coronavirus typically causes nothing more than a cold in humans, but the current coronavirus outbreak in the news is caused to a new, bad strain. (19 pts) -bat_Cov bat_Cov bat_Cov 2019-nCov 2019-nCov The virus phylogeny at right was recently published, but was available pre- publication. (Urgent research often has "accelerated previews" available early.) 2019-nCov bat COV bat_COV = coronavirus isolated from a bat human_CoV = coronavirus isolated from a person with a cold 2019-nCoV = coronavirus isolated from a person with the current outbreak 2012-MERS = unknown virus isolated from a person with whatever caused the Middle East Respiratory Syndrome (MERS) outbreak of 2012 bat_Cov bat_Cov bat_Cov bat Cov human coV a. Do the six human-infecting viruses form a monophyletic group in this phylogeny? yes no depends human_COV bat COV bat COV b. Is the virus that causes MERS a coronavirus? Circle one, and explain. yes no 1 unclear 2012-MERS bat Cov bat COV c. Is the human_CoV virus more closely related to the 2012-MERS virus or 2019-nCoV? Circle one, and explain. 2012-MERS / 2019-nCoV I equally related / this question's nonsense d. Hypothesis: "The current coronavirus outbreak stemmed from a regular human coronavirus becoming more virulent". What prediction does this hypothesis make for the phylogeny of coronavirus? (You can use terms like "would form a monophyletic group", "would be more closely related to", "would be nested within".) e. Use the phylogeny to hypothesize how the current coronavirus outbreak arose, and explain your reasoning. f. How might this phylogeny influence how we treat the current outbreak or prevent the next outbreak?

Answer 1

6.a. No, all the six human-infecting viruses in the given phylogeny does not form a monophyletic group.

b. No, the virus causing MERS is not a coronavirus although it has the same ancestor as the virus causing coronovirus in bats.

c. The human coronavirus is more closely related to the 2012-MERS than the 2019-CoV. The human coronavirus shares a more recent common ancestor with the 2012-MERS than the 2019-CoV, therefore, it is clear that it is more closely related to the MERS virus.

d. The hypothesis that 'the current coronavirus outbreak stemmed from a regular human coronavirus becoming more virulent' predicts that the regular human coronavirus evolved and became more virulent. It suggests that the current corenavirus is closely related to the normal human coronavirus.