SUMMARY We are requesting supplementary equipment purchase funds for the parent grant (GM151683, “Hypothesis Testing using Phylogenies for the 21st century”). The requested funds will be used to purchase an ARM Ampere Altra computing cluster with 1920 3GHz compute cores (15 x 128), a head node, and storage (quote included). The computational capacity afforded by this cluster will allow us to better execute the specific aims concerned with simulations, model validation, and complex model development. Second, we will provide a direct service to the broader research community by expanding the Datamonkey (datamonkey.org) server to run on the new cluster in addition to the older existing computing resources, expecting to realize >$120,000 of free compute (see research plan) per year for the worldwide research community.