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Evolution by Catastrophe: Does it indicate Intelligent Design? (cont.)
By Bibhu Dev Misra (IIT, IIM)

The 26 million year cycle of mass extinction has significant implications for evolutionary biology. As per Darwinism, the evolutionary process is gradual, and takes place through ‘natural selection’. Yet, the paleontological data tells us something quite different. In addition, evolution seems to be guided by extraterrestrial factors. The presence of enhanced levels of iridium in the soil layers at the geological boundaries, as well as the discovery of impact craters on the earth that match with the extinction periodicity, have convinced scientists that the extinction events have been triggered by large body impacts from outer space.

David Raup, paleontologist at the University of Chicago, who along with Sepkoski had identified the extinction periodicity in the fossil records, states:

‘The implications of periodicity for evolutionary biology are profound. The most obvious is that the evolutionary system is not ‘alone’ in the sense that it is partially dependent upon external influences more profound than the local and regional environmental changes normally considered... With kill rates for species estimated to have been as high as 77% and 96% for the largest extinctions, the biosphere is forced through narrow bottlenecks and the recovery from these events is usually accompanied by fundamental changes in biotic composition. Without these perturbations, the general course of macroevolution could have been very different. ‘[i]

He further states that, ‘the largest mass extinctions produce major restructuring of the biosphere wherein some successful groups are eliminated, allowing previously minor groups to expand and diversify…There is little evidence that extinction is selective in the positive sense argued by Darwin. It has generally been impossible to predict, before the fact, which species will be victims of an extinction event.’[ii]

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Endnotes

  1. Raup and Sepkoski, PNAS, USA, Vol 81, pp 801-805, Feb 1984 [back to text]
  2. The role of extinction in evolution, D M Raup, PNAS July 19, 1994 vol. 91 no. 15 6758-6763 [back to text]

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