Cause of Cambrian Explosion - Terrestrial or Cosmic? - ScienceDirect
https://www.sciencedirect.com/science/article/pii/S0079610718300798
We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus. A third focus concerns the micro-organism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space. In our view the totality of the multifactorial data and critical analyses assembled by Fred Hoyle, Chandra Wickramasinghe and their many colleagues since the 1960s leads to a very plausible conclusion –
life may have been seeded here on Earth by life-bearing comets as soon as conditions on Earth allowed it to flourish (about or just before 4.1 Billion years ago); and living organisms such as space-resistant and space-hardy bacteria, viruses, more complex eukaryotic cells, fertilised ova and seeds have been continuously delivered ever since to Earth so being one important driver of further terrestrial evolution which has resulted in considerable genetic diversity and which has led to the emergence of mankind.
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mainstream thinking on the origin and further evolution of life on Earth is anchored firmly in the “Terrestrial” paradigm. Our aim here is to facilitate further discussion in the biophysical, biomedical and evolutionary science communities to the quite different H-W “Cosmic” origins viewpoint which better handles, in our opinion, a wider range of physical, astrophysical, biological and biophysical facts often quite inexplicable, if not contradictory, under the dominant Terrestrial neo-Darwinian paradigm.
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discuss the recent phylogenetic data which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma (the widely agreed epochal event in the evolutionary history of multicellular life on Earth). These types of reverse transcribing and genome integrating viruses are speculated to be plausibly associated with major evolutionary genomic processes. We believe this coincidence with the Cambrian Explosion may not be fortuitous but consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with cometary-bolide bombardment events delivering hypothesized viruses, microorganism, and more complex eukaryotic systems to Earth during the past 4.5 Billion years of Earth history. Not all of such incoming living systems would necessarily take hold, and substantial terrestrial based evolutionary processes (whatever the actual molecular genetic mechanisms) are also expected to be on going.
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Perhaps the most important astronomical data relevant to the theory of cosmic life to emerge in the past decade are the detections of habitable exoplanets – planets outside of our solar system. The total estimated tally of such Earth-like planets in our Milky Way galaxy alone now stands at 100 billion, and with 100 billion or so galaxies in the observable universe the grand total stands at 1022. Because exchanges of possibly fecund material between neighbouring habitats is more than likely, panspermia and the theory of cosmic life could be argued to become inevitable facts.
The paradigm shift to this critical viewpoint, whilst underway, is by no means complete - yet we believe the historical moment has now arrived for a comprehensive and considered cross-disciplinary review of much of the relevant evidence, which this paper endeavours to represent.