On Jul. 24, 2025, a world-first study led by Museums Victoria Research Institute has revealed that beneath the cold, dark, pressurised world of the deep sea, marine life is far more globally connected than previously imagined.

Published in Nature, this landmark study maps the global distribution and evolutionary relationships of brittle stars (Ophiuroidea), the ancient, spiny animals found from shallow coastal waters to the deepest abyssal plains, and from the equator to the poles.

By analysing the DNA of thousands of specimens collected on hundreds of research voyages and preserved in natural history museums around the world, scientists have uncovered how these deep-sea invertebrates have quietly migrated across entire oceans over millions of years, linking ecosystems from Iceland to Tasmania.

This unprecedented dataset offers powerful new insights into how marine life has evolved and dispersed across the oceans over the past 100 million years. The research shows that deep-sea communities, particularly at temperate latitudes, are more closely related across regions than their shallow-water counterparts. For example, marine animals found off southern Australia share close evolutionary links with those in the North Atlantic, on the other side of the planet.

Yet, the deep sea is not uniform. While species can spread widely, factors such as extinction events, environmental change, and geography have created a patchwork of biodiversity across the seafloor.

This research not only transforms our understanding of deep-sea evolution but also highlights the enduring scientific value of museum collections. The DNA analysed in this study came from specimens collected during 332 research voyages, many undertaken decades ago, and preserved in institutions including Museums Victoria’s Research Institute.

This world-leading project was made possible through partnerships with more than 40 institutions globally, spanning natural history museums, universities and marine research organisations including support via grants of sea time on RV Investigator from Australia’s CSIRO Marine National Facility.