Wickramasinghe and Hoyle also happened to be responsible for another space biology thesis. Only this one is based on more than just the origins of organic chemistry. The Hoyle Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology makes the rather simple claim that the direction of evolution has been significantly affected by biochemistry that didn't start on our planet.

In Wickramasinghe's own words, "Comets are the carriers and distributors of life in the cosmos and life on Earth arose and developed as a result of cometary inputs." Those inputs, Wickramasinghe argues, aren't limited to a generous sprinkling of space-baked amino acids, either. Rather, they include viruses that insert themselves into organisms, pushing their evolution into whole new directions. The report, titled "Cause of Cambrian Explosion – Terrestrial or Cosmic?", pulls on existing research to conclude that a rain of extra-terrestrial retroviruses played a key role in the diversification of life in our oceans roughly half a billion years ago. Thus retroviruses and other viruses hypothesised to be liberated in cometary debris trails both can potentially add new DNA sequences to terrestrial genomes and drive further mutagenic change within somatic and germline genomes," the authors write.

Let that sink in for a moment. And take a deep breath before continuing, because that was the tame part. It was during this period that a group of molluscs known as cephalopods first stretched out their tentacles from beneath their shells, branching into a stunning array of sizes and shapes in what seemed like a remarkably short time frame. The genetics of these organisms, which today include octopuses, squid, and cuttlefish, are as weird as the animals themselves, due in part to their ability to their ability to edit their DNA on the fly.The authors of the paper make the rather audacious claim that these genetic oddities might be a sign of life from space. Not of space viruses this time, but the arrival of whole genomes frozen in stasis before thawing out in our tepid waters.

"Thus the possibility that cryopreserved squid and/or octopus eggs, arrived in icy bolides several hundred million years ago should not be discounted," they write. In his review of the paper, medical researcher Keith Baverstock from the University of Eastern Finland, concedes that there's a lot of evidence that plausibly aligns with the H-W thesis, such as the curious timeline of the appearance of viruses.