the fossil plant and animal records of the region, integrated with extensive climate modeling efforts to provide a dynamic understanding of the findings. This type of collaboration is a useful model for us to consider, but it lacks a critical element—the significant funding that will be required to undertake the types of projects proposed here.
We envision a new scientific program for international climate and human evolution studies that involves both essential and supporting components:
Essential Components Three elements must be carefully integrated to comprise the core program of research:
A major exploration initiative to locate new fossil sites, and to broaden the geographic and temporal sampling of the fossil and archaeological record;
A comprehensive, integrated scientific drilling program in lakes, lake bed outcrops, and ocean basins surrounding the regions where hominins evolved, to vastly improve our understanding of the climate and environmental history of these regions;
A major investment in climate modeling experiments for the key time intervals and regions that are critical for understanding human evolution, focused on understanding the regional climate patterns and fundamental climate forcing mechanisms, and to model at a more local scale the interactions between climate, ecosystems, and species population dynamics.
Supporting Components In addition, there are a number of components that will be required to complement the core research effort:
A systematic analysis of fossil sites and collections, with application of new imaging and dating technologies, to better describe the nature and timing of the hominin evolutionary lineage;
An investigation of how population sizes have changed over the past 500,000 years, based on whole-genome samples of DNA from a number of species, including humans;
Selected investigations of ecosystem dynamics through the collection of modern climate and calibration data to more accurately quantify relationships between the environment and the proxy records of environment preserved in sediments and fossils;
Development of the informatics and data archiving tools needed to both provide permanent storage for the wide array of information collected by the activities listed above and to facilitate continued access to and the synthesis of this information.