Exploring the evolution of animals at deep-sea hot springs

We are exploring the role of hydrothermal vents in driving the evolution of novel adaptations in deep-sea animals, throughout the 500+ million year history of complex life on our planet.

In many parts of the deep ocean, underwater hot springs (or ‘hydrothermal vents’) spout hot, chemical and mineral-rich fluid into the cool seawater of the deep sea. These seemingly inhospitable environments support highly productive ecosystems, comprised of specialised animals that live in close-knit associations, or symbioses, with the microbes that provide their energy.

Because hydrothermal vents in the deep sea are so isolated, it was once thought that vent animals were sheltered from major perturbations such as mass extinctions that reconfigured the rest of the biosphere over deep time. More recent studies suggest that intriguingly, rather than acting as sheltering refuges, deep-sea animals from various lineages have continually adapted to hydrothermal vents throughout Earth’s history.

Thus, hydrothermal vents appear to exert an important influence on the evolution of animal life in the deep sea, promoting adaptation to conditions of variable temperature and acting as a biodiversity ‘pump’ to create new species in the oceans over time.

Understanding the ‘when’ and ‘how’ of adaptation of animals to hydrothermal vents can therefore provide vital insights into how animals in the deep sea respond to major environmental stresses such as climate change and pollution, as well as into the dynamics of evolution in the deep ocean.

Objectives

Our work is split across four major objectives:

• We are trying to find the very oldest hydrothermal vent animals by studying ancient rocks dating back to the Cambrian period, over 500 million years ago.
• We are mapping the evolution and extinction of vent animals over a remarkable 100 million year slice of Earth’s history preserved in the Ural Mountains, Russia.
• We are studying the ancient microbes preserved alongside the vent animal fossils using the latest imaging and chemical analysis methods.
• For the first time, we are investigating genetic processes involved in the colonisation of vents by animals in modern vent ecosystems.

The team

Our project unites a multidisciplinary team of researchers from mineralogy, palaeontology, deep-sea biology and genetics from around the UK. We will also work in partnership with NERC research facilities located in Scotland, as well as with an international network of collaborators.

Methods

We will assemble primary data from field studies of key geological localities in Norway, Canada and Tasmania, which likely contain the oldest known bone-fide vent animals, and the southern Ural Mountains where a remarkable 100 million year fossil history of ancient vents is preserved. Together, these regions contain some of the best-preserved ancient hydrothermal vent deposits in the world. Collected fossil samples will be subjected to new detailed palaeontological investigations, and high resolution sulphur isotopic analyses.

To investigate recent and ongoing adaptation and speciation at modern hydrothermal vents we will work on samples of fauna that we can observe colonising new hydrothermal systems, such as those recently discovered in Iceland, using advanced DNA techniques.