The fossil record was undoubtedly Darwin’s Nemesis. This archive was supposed to have recorded the slow descent-with-modification which represented the core of his evolutionary theory. The problem was the lack of abundant transitional forms. Darwin managed to deflect this challenge by invoking the extreme imperfection of the fossil record (poor preservation).

However, the particular case of the surprising diversity of creatures in the Cambrian, known today as ‘the Cambrian explosion’ (at that time, the lowest fossil-bearing sediments known were of ‘Silurian age’) and the lack of fossil ancestors to these in lower strata, was something he could not explain away:

“To the question why we do not find records of these vast primordial periods, I can give no satisfactory answer. Several of the most eminent geologists, with Sir R. Murchison at their head, are convinced that we see in the organic remains of the lowest Silurian stratum the dawn of life on this planet. Other highly competent judges, as Lyell and the late E. Forbes, dispute this conclusion. We should not forget that only a small portion of the world is known with accuracy.”1

Well, 130 years later Stephen Jay Gould wrote:

“Darwin has been vindicated by a rich Precambrian record, all discovered in the past thirty years. Yet the particular character of this evidence has not matched Darwin’s prediction of a continuous rise in complexity toward Cambrian life, and the problem of the Cambrian explosion has remained as stubborn as ever—if not more so, since our confusion now rests on knowledge, rather than ignorance, about the nature of the Precambrian life.”2

Although first studied by Soviet geologists in the 1950s in the sediments of the East European and the Siberian Platforms, this Precambrian assemblage of multicellular organisms first gained wide recognition and interest at Ediacara in South Australia’s Flinders Ranges. It was added to the geologic time scale in 2006.3….

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