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Melvyn Bragg and guests discuss extremophiles, the organisms thriving in very harsh conditions on Earth and providing clues to life forms on other planets.

In 1977, scientists in the submersible "Alvin" were exploring the deep ocean bed off the Galapagos Islands. In the dark, they discovered hydrothermal vents, like chimneys, from which superheated water flowed. Around the vents there was an extraordinary variety of life, feeding on microbes which were thriving in the acidity and extreme temperature of the vents. While it was already known that some microbes are extremophiles, thriving in extreme conditions, such as the springs and geysers of Yellowstone Park (pictured), that had not prepared scientists for what they now found. Since the "Alvin" discovery, the increased study of extremophile microbes has revealed much about what is and is not needed to sustain life on Earth and given rise to new theories about how and where life began. It has also suggested forms and places in which life might be found elsewhere in the Universe.


Monica Grady
Professor of Planetary and Space Sciences at the Open University

Ian Crawford
Professor of Planetary Science and Astrobiology at Birkbeck University of London


Nick Lane
Reader in Evolutionary Biochemistry at University College London

Producer: Simon Tillotson.

Available now

43 minutes

Last on

Thu 25 Jun 2015 21:30


Monica Grady at the Open University

Ian Crawford at Birkbeck, University of London

Nick Lane at University College London

Extremophile - Wikipedia

Hydrothermal vent - Wikipedia

Origins of life – Royal Society Summer Science Exhibition

BBC GCSE Bitesize – Adaptations in organisms

Extremophiles – National Oceanic and Atmospheric Administration

Icy volcanoes offer clues for life on Mars – Planet Earth Online



Lewis Dartnell, Life in the Universe (Oneworld Publications, 2007)

Cindy Lee Van Dover, The Ecology of Deep-Sea Hydrothermal Vents (Princeton University Press, 2000)

Franklin M. Harold, In Search of Cell History: The Evolution of Life's Building Blocks (University of Chicago Press, 2014)

Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth (Princeton University Press, 2003)

Nick Lane, The Vital Question: Why is life the way it is? (Profile Books, 2015)

Woodruff T. Sullivan and John A. Baross (eds.), Planets and Life: The Emerging Science of Astrobiology (Cambridge University Press, 2007)

David A. Wharton, Life at the Limits: Organisms in Extreme Environments (Cambridge University Press, 2002)



Role Contributor
Presenter Melvyn Bragg
Interviewed Guest Monica Grady
Interviewed Guest Ian Crawford
Interviewed Guest Nick Lane
Producer Simon Tillotson


  • Thu 25 Jun 2015 09:00
  • Thu 25 Jun 2015 21:30

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