Reason for More Confidence in a Phylogenetic Tree based on the Pseudogene

Question

You are given molecular sequence data for the GULO pseudogene from four species of primates: Pan troglodytes (common chimpanzee, abbreviated Pt below), pongo pygmaeus (Bornean orangutan, Pp), homo sapiens (human, Hs) and Macaca fascicularis (crab--- eating macaque).

A pseudogene is a region of DNA that is derived from a functional gene, but no longer codes for a protein (i.e., it is not expressed at all). In each of these primates, there is also a version of GULO that is functional (i.e., it does code for a pretein). Give one reason why you would have more confidence in a phylogenetic tree based on the pseudogene than one based on the functional gene.

Summary

This question belongs to biology and discusses about molecular sequence data for the GULO pseudogene from four species of primates.

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