List of top Applied Ecology & Evolution Questions on Evolutionary Biology

The phylogeny below shows the relationship between six species based on whole genome data. The sequence of a part of a particular gene from each species is provided at the tips of the tree.

Based on the principle of parsimony, which one of the following is the expected sequence for the ancestor X?

Which one of the following concepts describes a co-evolutionary arms race between a pathogen and its host?

Which one of the following phylogenetic trees illustrates the relationship between Archaea, Bacteria and Eukarya? The figure shows four candidate cladograms, labelled P, Q, R and S, each grouping the three domains of life in a different branching pattern.