Photosynthesis

In Our Time | 15 May 2014 | 0h 46m | Listen Later  | iTunes
Melvyn Bragg and his guests discuss photosynthesis, the process by which green plants and many other organisms use sunlight to synthesise organic molecules. Photosynthesis arose very early in evolutionary history and has been a crucial driver of life on Earth. In addition to providing most of the food consumed by organisms on the planet, it is also responsible for maintaining atmospheric oxygen levels, and is thus almost certainly the most important chemical process ever discovered.

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Echolocation

In Our Time | 21 June 2018 | 0h 51m | Listen Later  | iTunes
Melvyn Bragg and guests discuss how some bats, dolphins and other animals emit sounds at high frequencies to explore their environments, rather than sight. Bats that echolocate have a range of frequencies for different purposes and techniques for preventing themselves from becoming deafened by their own sounds. Some prey have evolved ways of detecting when bats are emitting high frequencies in their direction, and some fish have adapted to detect the sounds dolphins use to find them.

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