Question

Once all positions in the sequence alignment have been examined, the likelihoods given by each column in the alignment for each tree are _____ to give the likelihood of the tree.

(a) multiplied

(b) added

(c) divided

(d) squared

This question was addressed to me in an interview.

The origin of the question is The Maximum Likelihood Approach in chapter Phylogenetic Tree Construction Methods and Programs of Bioinformatics

Answer 1

Correct option is (a) multiplied

The best explanation: Because these likelihoods are very small numbers, their logarithms are usually added to give the logarithm likelihood of each tree. The most likely tree given the data is then identified.