JMU Evolutionary Biology Creating a Phylogenetic Tree Paper

While moving samples from your lab’s DNA collections, one of your employees has lost the tag for a DNA sample. In order to identify the sample, you sequence DNA from the sample (called species “X”), and align it with sequences of the same gene from three other species. Both A and B are animals, while C is a plant . In the alignment below, a dot indicates that a species has the same base as the top (first) sequence. In other words, only the differences from the first sequence are shown.

A. Complete the genetic distance matrix below comparing pairwise differences as genetic distance between all species (labeled A-X. Fill in the correct values for the six empty, unshaded boxes.

B. Based on the distance matrix above, reconstruct a distance-based phylogenetic tree that best fits the data. Label all the branches with the appropriate branch length. Show your work.

(c) (Based on your results from this preliminary analysis, is species X most likely a plant or an animal?