Well, you learn something every day – especially if it’s Thursday and time for In Our Time! Today Melvyn Bragg and guests Martin Brasier, Richard Corfield and Rachel Wood discussed the Ediacara Biota, the Precambrian life forms which vanished 542 million years ago, and whose discovery proved Darwin right in a way he never imagined.
Darwin was convinced that there must have been life before the Cambrian era, but he didn’t think it was possible for fossils like the Ediacara to have been preserved. These sea-bed organisms were first unearthed in the 19th century, but were only recognised as Precambrian in the mid-20th century.
This was an astonishing discovery. Ever since, scientists have been working to determine its significance. Were the Ediacara the earliest forms of animal life? Or were they a Darwinian dead end? Either way, it is argued, they reveal some of the secrets of the workings of evolution.
The Ediacara Biota, or Ediacaran Assemblage, named for the Ediacara Hills of South Australia, has been uncovered at more than 30 sites worldwide on all continents except Antarctica.
The biota includes oval, frondose, and spindle-shaped forms of unknown affinity to later organisms. Based on shared taxa in various localities, the fossil locations dating from the Vendian can be assigned to three groups:
(1) Newfoundland (Mistaken Point Formation) and Charnwood Forest, UK.
(2) Ediacara Hills (SA), Baltica, Siberia (White Sea) and NW Laurentia.
(3) Namibia, SW Laurentia, S. America and S. China.