Cause of Cambrian Explosion – Terrestrial or Cosmic?
A paper recently published in “Progress in Biophysics and Molecular Biology” suggests that cephalopods did not evolve on Earth, but arrived in the form of frozen eggs around 270+ million years ago. Cephalopods are of course pretty weird compared to just about all other animals, and their nervous systems and DNA are different, but this does seem to be a bit of a stretch.
Abstract:
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.
I’ve personally never been especially impressed with the notion of panspermia.Not because it’s necessarily impossible, but because it seems to be simply adding an extra step to the explanation of biogenesis. The fossil evidence shows that life arose on Earth more than 3 billion years ago, so having added extraterrestrial weirdness added 500 million and 270 million years ago seems unnecessary.
But it does explain Cthulhu.