Question

Which of the following is untrue about the Fitch–Margoliash?

(a) Method selects a best tree among all possible trees based on minimal deviation between the distances calculated in the overall branches in the tree and the distances in the original dataset

(b) It starts by randomly clustering two taxa in a node

(c) It starts by creating three equations to describe the distances

(d) The method searches for some specific tree topologies

The question was asked by my school teacher while I was bunking the class.

This key question is from Distance Based Methods in section Phylogenetic Tree Construction Methods and Programs of Bioinformatics

Answer 1

The correct option is (d) The method searches for some specific tree topologies

The explanation: It solves the three algebraic equations for unknown branch lengths. The clustering of the two taxa helps to create a newly reduced matrix. This process is iterated until a tree is completely resolved. The method searches for all tree topologies and selects the one that has the lowest squared deviation of actual distances and calculated tree branch lengths.