Many plant species have lineage specific metabolic pathways, or specialized metabolic pathways. How have these pathways evolved? The evolution of metabolic pathways is often a result of gene duplication and subsequent divergence of gene function. New metabolic pathways can contribute to speciation. One example is the biosynthesis of lignin in grasses compared to other plants. The lignin of grasses is synthesized using tyrosine, while other plants use phenylalanine. The goal of this project is to determine when key enzymes in the lignin pathway diverged between grasses and other monocots in order to predict important divergence times in grasses.