Chasing Darwin’s Shadow: Geophysics and Evolution in the Galapagos

In the autumn of 1835, young geologist Charles Darwin spent a month exploring the Galapagos Islands, coming to the realization that these new and ephemeral volcanic habitats had given rise to new species of otherwise familiar animals, and leading him to conclude that biological evolution was a fact, with natural selection as the primary mechanism.

The active Galapagos mantle plume (“hotspot”) and mid-ocean ridge system is a spectacular showplace for plume-ridge interaction, with geophysical and geochemical signatures that elucidate upper mantle dynamics and evolution, and a geological history of continuously emerging and subsiding island habitats that have provided stepping stones for at least 20 million years of evolutionary divergence for mainland-derived species such as iguanas, tortoises, and finches.

This talk will show how several different lines of geophysical investigations are revealing new secrets about the geological evolution of the Galapagos plume-ridge system, how these discoveries are helping us understand volatile (H2O) fluxes from the deep mantle, and new horizons for how to formally combine increasingly rich genetic constraints on evolutionary biology with geology to obtain a more integrated understanding of geo-biological evolution in ocean island systems.