9. Neighbour-joining method

Distance based methods: Minimize the number of global changes between each pair in a group of sequences previously aligned.

Least squares approach: From a matrix of distances D between species, find a phylogenetic tree that predicts a set of distances d so that the following expression is minimized:


  • Join the clusters that are close to another and also apart from the rest
  • Heuristic: Minimize the sum of the branch lengths in the tree
  • Additivity of evolutionary distances