Question

Compare the phylogenies ( the cladistics and UPGMA methods). Describe one major difference between the two evolutionary hypotheses that these trees represent. Why do the contrasting philosophies underlying parsimony versus distance methods give you a different phylogeny?

Answer 1

Cladistics is the study of the pathways of evolution. It can be a tree-like network that expresses such ancestor-descendant relationships is represented by a cladogram. Thus, a cladogram refers to the topology of a rooted phylogenetic tree.

Phenetics follows degree of similarity among a group of organisms on the basis of molecular, phenotypical, or anatomical level. A tree-like network used to express phenetic relationships is called a phenogram.

Maximum parsimony method is a typical cladistic approach, whereas the UPGMA method is a typical phenetic method. The maximum likelihood method is a phenetic method because it can be well established statistically.

UPGMA method, neighbor’s relation method, transformed distance methods are the distance methods, while the parsimony method is a character-state method; the parsimony method is generally very effective. Distance methods only give one tree, while parsimony analyses many trees and may suggest multiple, equally likely trees, none of which is necessarily the right one.