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1. If you were going to use one of the proteins to build a phylogenetic tree of

ID: 300317 • Letter: 1

Question

1. If you were going to use one of the proteins to build a phylogenetic tree of various mammalian species (which diverged during the last 50 million years), which protein sequence would be most useful? Justify your answer.


2. If you were going to use one of the proteins to build a phylogenetic tree of various plant species (which diverged during the past 500 million years), which protein sequence would be most useful? Justify your answer.


3. If you were going to use one of the proteins to build a phylogenetic tree of a mixture of plant and animal species (which diverged 1200 million years ago), which protein sequence would be most useful? Justify your answer.

00 of amino 75 acid subs. per 100 residues 375 750 125 1500 Millions of years since divergence

Explanation / Answer

From the graph, we choose protein A ,

Because protein A changed during the last 50 years.

During, last 50 million years, less sequence divergence occurs between the genes compared to the first portion of the graph. A gene that shows sufficient divergence is chosen for phylogenetic information.