I am a junior at Ward Melville High School. The Shimodaira-Hasegawa test is known for its conservative calculations, yet it has still been cited more than 1,500 times in scientific papers. This poses the question: how conservative is the statistical test? Using molecular data simulated on known phylogenies we hoped to determine what causes the differences in the null distribution of the Shimodaira-Hasegawa Test (SH test), and later use them to disclose what might incur type I and type II errors. This project has taught me how to program in R, write trees in Newick format, simulate molecular sequences using Seq-Gen, and has given me experience on the first hand basis of data analysis. This has given me the experience in a lab which I hoped for to direct my future education in the sciences and I hope to use this project specifically to apply to science competitions.