Question

bat Cov -bat_COV 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) The virus phylogeny at right was recently published, but was available pre- publication. (Urgent research often has "accelerated previews" available early.) -bat_CoV bat COV 2019-nCoV 2019-nCoV - 2019-n Cov bat_Cov 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 human CoV a. Do the six human-infecting viruses form a monophyletic group in this phylogeny? ப ப ப yes no depends human_Cov bat COV b. Is the virus that causes MERS a coronavirus? Circle one, and explain. yes no 1 unclear -bat_Cov 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 / 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

a) These are the 6 species highlighted species, and the answer is no, they do not form a monophyletic group, they dispersed along different groups

b) Yes it is. We can know that because it is in the coronavirus phylogeny, it is inside this phylogeny

c) They are more closely related to 2012 MERS. You can know that by counting the number of nodes you require to go from one group to the other

d) This means one of the 2 strains of human coronavirus branched and created this more virulent strain, that would mean it would form a phylogenetic group with the human coronavirus, or in other words it is nested in this group, or in other words it is a sister species to human coronavirus in this phylogeny

e) Well, now that we know where was it born and who are the closely related strains, we can state that current outbreak was already in humans, since it was born from another human coronavirus that means this recent ancestor most likely was in a human, then while replicating it mutated and created this more virulent strain

f) Well, by knowing its closely related strains we can focus on fighting it according to this, if this strain was born form certain human coronavirus then it would be a good logic to fight just as we fight the human coronavirus, using what is effective against them