This repository contains the data underlying Figure 1 in our [Perspective][1] on the seminal 1960 [PNAS paper][2] "A Comparison of Animal Hemoglobins by Tryptic Peptide Pattern Analysis" by Emile Zuckerkandl, Richard T. Jones and Linus Pauling. The data is separated into three folders, each containing the original data, analysis results and plots, for the chimpaznzee, human, cow and pig HBB genes (in the "FASTA sequences" folder), and corresponding ion trap and Orbitrap data respectively. The "README.txt" files within each folder contains a listing and explanation of the different files in the folder. The phylogenetic analysis based on the Orbitrap data was conducted using compareMS2, originally published in [this paper][3] and now available on [GitHub][4]. These data were graciously provided with permission from a collaboration with Dr. Michael G. Janech (College of Charleston) as part of the CoMPARe Program (Comparative Mammalian Proteome Aggregator Resource). Specifically, the cow samples were provided by Dr. Paola Boggiatto and Dr. Randy Sacco at the National Animal Disease Center, ARS, USDA, Ames, IA. The chimpanzee samples were provided by the Chattanooga Zoo, while the pig samples were from the Medical University of South Carolina (Charleston, SC). The human data were generated using independent digestions of NIST SRM 909c Frozen Human Serum. In addition to institutional permits and approval, data collection was performed under NIST ACUC MML-AR20-0001. The phylogenetic analysis based on the HBB sequences were performed in [MEGA X][5], after MUSCLE alignment. The final phylogennetic trees were calculated using UPGMA in MEGA X. [1]: https://doi.org/10.1021/acs.jproteome.1c00528 [2]: https://www.pnas.org/content/pnas/46/10/1349.full.pdf [3]: https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/rcm.6162 [4]: https://github.com/524D/compareMS2 [5]: https://www.megasoftware.net/