Questions
Question 1
A phylogenetic diagram for multiple Plasmodium vivax strains from different world regions is shown below.
Part a
[1]
Identify the pair of strains that share the most recent common ancestor.
Part b
[2]
State what a node represents in a cladogram and define a clade.
Part c
[2]
Deduce, with one piece of evidence from the branching pattern, whether Europe strain E1 is more closely related to Central America strain C2 or to East Asia strain A1.
Part d
[3]
Explain how the molecular clock can be used to estimate the divergence time between Central America C1 and South America S1, and outline one limitation of this approach.
Part e
[1]
Suggest one evolutionary reason why P. vivax is now rare in Africa despite an African common ancestor.