A summary of
decades of research on a rather 'out-there' idea involving viruses from space
has recently been published, and it's raising questions on just how scientific
we can be when it comes to speculating on the history of life on Earth.
This
may sound weird and strange but its serious.
It's easy to
throw around words like crackpot, rogue, and maverick in describing the
scientific fringe, but every now and then a paper like this comes along,
leaving us blinking owlishly, unsure of where to even begin.
A total of
33 names are listed as authors on this review, which was published by Progress
in Biophysics and Molecular Biology. The journal is peer reviewed and fairly
well cited. So it's not exactly a small, or a niche pay-for-publish source.
Science
writer Stephen Fleischfresser goes into depth on the background of two of the
better-known scientists involved: Edward Steele and Chandra Wickramasinghe.
It's well worth a read. For a tl;dr version, Steele is an immunologist who
already has a fringe reputation for his views on evolution that relies on
acquiring gene changes determined by the influence of the environment rather
than random mutations, in what he calls meta-Lamarckism.
Wickramasinghe,
on the other hand, has had a somewhat less controversial career, recognized for
empirically confirming Sir Fred Hoyle's hypothesis describing the production of
complex carbon molecules on interstellar dust.
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 hypothesized 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.
But that's just not how science advances. "I believe this paper justifies scepticism of the scientific value of stand alone theories of the origin of life," Baverstock argues. "The weight of plausible, but non-definitive, evidence, great though that might be, is not the point."
While the
idea is as novel and exciting as it is provocative, nothing in the summary
helps us better understand the history of life on Earth any better than
existing conjectures, adding little of value to our model of evolution. Still,
with solid caveats in place, maybe science can cope with a generous dose of
crazy every now and then.
Journal
editor Denis Noble concedes that 'further research is needed', which is a bit
of an understatement. But given the developments regarding space-based organic
chemistry in recent years, there's room for discussion.
"As space chemistry and biology grows in importance it is appropriate for a journal devoted to the interface between physics and biology to encourage the debates," says Noble. "In the future, the ideas will surely become testable."
Just in case
those tests confirm speculations, we recommend being well prepared for the
return of our cephalopod overlords. Who knows when they'll want those eggs
back? This research was published in Progress in Biophysics and Molecular Biology.