A central goal of the paleosciences is to assign causality to macroevolutionary changes in the paleontological record using a geologic toolkit that includes field observations, geophysical data, geodynamic modeling, geochronology, geochemical proxies, and paleoclimate simulations. However, developing records and predictions at the same temporal resolution from terrestrial rocks, on a regional scale, presents inherent challenges. The East African Rift System (EARS) offers an exceptional setting for addressing this challenge due to its extensive outcrops of sedimentary rocks and rich faunal record, providing a unique opportunity to illuminate the environmental conditions that influenced the origin of our own lineage. In this presentation, I will introduce the design, progress, and latest results of the Turkana Miocene Project (TMP). The TMP is an interdisciplinary initiative investigating the relationship between tectonics, climate, and the transformation of terrestrial ecosystems and faunal assemblages in the Turkana Basin, Kenya, from the latest Oligocene through the Late Miocene (~28 to 5 Ma). The TMP’s integrative research approach combines geophysical, sedimentological, geochemical, and fossil data from fieldwork with cutting-edge global and regional Miocene climate simulations, enabling direct model-proxy comparisons. Additionally, the project employs a 4D forward thermo-mechanical geodynamic model to assess the tectonic evolution of the basin. The Oligo-Miocene sedimentary rocks in Turkana span a critical interval of long-term Neogene cooling, punctuated by the Miocene Climatic Optimum (~17 to 15 Ma). These rocks also record significant regional tectonic events, such as the docking of Africa with Eurasia and the closure of the Tethys Seaway, which facilitated faunal interchange between the two continents. The initiation of the EARS during the Early Miocene led to increased volcanism and the formation of topographic heterogeneity, which supported diverse habitats. This period coincided with the proliferation of apes and, by the Late Miocene, the emergence of the first hominins—the tribe containing modern humans and their extinct ancestors. The global expansion of C4 grasslands, particularly in eastern Africa around ~9.5 Ma, closely aligns with the origin of mammal lineages that now comprise this region’s iconic modern fauna.