Question

What is the difference between a molecular phylogeny reconstructed by parsimony versus maximum likelihood?

A. Parsimony aims to minimize the total number of evolutionary changes, while maximum likelihood estimates the probability of the observed data given a specific evolutionary model.

B. Parsimony relies on probabilistic models to estimate evolutionary relationships, while maximum likelihood emphasizes simplicity in reconstructing phylogenies.

C. Parsimony is more computationally intensive than maximum likelihood, which focuses on minimizing the complexity of the phylogenetic tree.

D. Parsimony and maximum likelihood both prioritize the accuracy of ancestral state reconstructions, but they differ in their approach to handling missing data.

Answer 1

The difference lies in their methods: parsimony seeks the simplest explanation with the fewest changes, whereas maximum likelihood calculates the probability of observed genetic data based on a specific evolutionary model.

Step-by-step explanation:

The main difference between molecular phylogeny reconstructed by parsimony and maximum likelihood methods relates to their approaches towards phylogenetic tree construction. Option A is correct. Parsimony aims to minimize the total number of evolutionary changes, suggesting that the simplest tree with the fewest evolutionary events is the most likely. It operates on the principle that fewer changes in a characteristic are more likely than more changes. Conversely, maximum likelihood estimates the probability of the observed data given a specific evolutionary model. It involves complex statistical techniques to calculate the likelihood that a particular phylogenetic tree would produce the observed data, thereby optimizing the tree reconstruction based on the chosen model.

Moreover, maximum parsimony is often explained through analogies such as if a group of people goes hiking in a forest preserve, it is parsimonious to assume that they would take established trails rather than forging new ones. However, the maximum likelihood approach considers the overall probability of such events, factoring in available models of evolutionary change. It applies a statistical framework that allows the calculation of the probability of observing the set of genetic data given a particular model of genetic sequence evolution.