Diffusion MR tractography is an exciting method to visualize pathways, but there are uncertainties in the accuracy of reconstructed tracts. There are very few, if any alternative methods, amenable to ensure the accuracy of diffusion MR tractography in humans. I discuss long-term efforts from my laboratory to broaden the repertoire of toolkits available to diffusion MR tractography in order to maximize its utility for the study of pathways in health, disease, and in human evolution. Our integrative approach, which captures variation across development, species, and scales of organization from transcription to pathway analysis serves to trace the evolution of pathways in human and nonhuman primates. Harnessing the power of diffusion MR tractography through an integrative lens enhances the study of human brain pathways.