You may or may not know this, but one of my favorite animals is the octopus. I've been fascinated by them since I was a kid and argued endlessly with my best friend down the street on which would prevail in a contest over the other: shark, or octopus? Well, obviously, sharks some time eat octopuses. But it isn't always the uneven contest one might think; consider this intriguing 2006 video from National Geographic magazine:
Well, chalk one up for octopuses: Cephalopods 1, Sharks 0. Lesson? Don't put your sharks in the same tank as your giant Pacific octopus, because they'll end up being lunch and leftovers.
So why all this bother about the octopus? It so happens that a few regular readers here know about my fascination with the creatures. For one thing, most scientists who have studied them think they are very smart, especially for creatures without a very long life span. They can actually learn from each other, perform complex tasks, and as anyone knows who has tried to keep them inside an aquarium tank, they are master escape artists. With that in mind several people sent the following story, probably knowing full well that because of my fascination with the creatures, I'd have to blog about it.
Indeed, that's true, and here we are. And as one might imagine, I am crawling way out on to the end of the twig of high octane speculation and hopefully won't fall off and into the dark waters below (do cephalopods eat caprae?) So what caught my eye? The paper itself is the rather bland scientific sort of thing:
The subject, as one may gather from reading the abstract, is the mystifying "Cambrian explosion" of life which scientists believe occurred approximately 500,000,000 years ago. In this explosion, there's a mystifying non-vertebrate presence: the octopus. Or as the abstract puts it:
A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus.
To my unscientific eyes, that's about as close as you can come to the statement: "We've got a problem," because after all, if one follows the standard models, the branches of the tree that led to you and me, and to the giant Pacific shark-devouring octopus, are thought to have begun to diverge about 850,000,000 years ago, with the modern octopus finally appearing about 250,000,000 years ago or so. But then the problem is admitted - or perhaps confessed - in much more stark terms a little later:
Even if we concede that the dominant neo-Darwinian paradigm of natural selection can explain aspects of the evolutionary history of life once life gets started, independent abiogenesis on the cosmologically diminutive scale of oceans, lakes or hydrothermal vents remains a hypothesis with no empirical support and is moreover unnecessary and redundant. With astronomical data now pointing to the existence of hundreds of billions of habitable planets in our galaxy alone (Abe et al., 2013; Kopparapu, 2013) such an hypothesis seeking an independent origin of life on any single planet seems to be no longer hardly necessary.
"Ok ok," I thought as I was reading the paper, "but can we please get to the octopus part now?" But no, we get a bit of a review of the panspermia idea of microbial life being delivered to Earth by rocks and cometary bombardment:
The recent report indicating evidence of microbial life in Canadian rocks that formed 4.1–4.23 billion years ago (Dodd et al., 2017), if accepted, makes it more difficult in our view to envisage the option of abiogenesis taking place anywhere on the Earth. The claim that these rocks may have been associated with hydrothermal vents still raises the question of how life could have originated in situ during the early Hadean epoch that was riddled with frequent and violent collisions by asteroids and comets. Rather we think it more reasonable to suggest that the particular evidence of microbial life in the Canadian rocks was delivered by cometary bolides, only to be instantly destroyed or carbonised on impact.
From the turn of the 20th century the resistance to panspermia had become ever more deeply entrenched in our scientific culture. Attempts by Hoyle and Wickramasinghe (Hoyle and Wickramasinghe, 1979, 1981, 1986, 1993; Wickramasinghe, 2015a,b) to re-examine and re-instate panspermia in the light of new evidence from astronomy and biology were often met with hostility (Hoyle and Wickramasinghe, 1986; Wickramasinghe, 2015a).
Of course I may be stretching things a bit with the change of "bollide" to "bombardment", but after all, bollides explode (q.v. the Chelyabinsk meteor incident), explosions are typical of bombardments, and... well, I'm sure some here can see which twig I'm crawling to the end of on today's (and tomorrow's) high octane speculation. After many fascinating further paragraphs arguing about the necessity for "fecund theories" and even a foray into "extant Martian life" and complex organics on comets, we finally get to some cephalopodal C-4 bombshells:
Evidence of the role of extraterrestrial viruses in affecting terrestrial evolution has recently been plausibly implied in the gene and transcriptome sequencing of Cephalopods. The genome of the Octopus shows a staggering level of complexity with 33,000 protein-coding genes more than is present in Homo sapiens (Albertin et al., 2015). Octopus belongs to the coleoid sub-class of molluscs (Cephalopods) that have an evolutionary history that stretches back over 500 million years, although Cephalopod phylogenetics is highly inconsistent and confusing (see Carlini et al., 2000; Strugnell et al., 2005, 2006, 2007; Bergmann et al., 2006). Cephalopods are also very diverse, with the behaviourally complex coleoids, (Squid, Cuttlefish and Octopus) presumably arising under a pure terrestrial evolutionary model from the more primitive nautiloids. However the genetic divergence of Octopus from its ancestral coleoid sub-class is very great, akin to the extreme features seen across many genera and species noted in Eldridge-Gould punctuated equilibria patterns (below). Its large brain and sophisticated nervous system, camera-like eyes, flexible bodies, instantaneous camouflage via the ability to switch colour and shape are just a few of the striking features that appear suddenly on the evolutionary scene. The transformative genes leading from the consensus ancestral Nautilus (e.g. Nautilus pompilius) to the common Cuttlefish (Sepia officinalis) to Squid (Loligo vulgaris) to the common Octopus (Octopus vulgaris, Fig. 5) are not easily to be found in any pre-existing life form – it is plausible then to suggest they seem to be borrowed from a far distant “future” in terms of terrestrial evolution, or more realistically from the cosmos at large. Such an extraterrestrial origin as an explanation of emergence of course runs counter to the prevailing dominant paradigm. (Emphasis added)
In other words, there's not much good evidence of evolutionary stages leading up to the creature, its complexity, large brains, weird camera-like eyes, and so on, appear all at once and very suddenly. Conclusion? Either some future to past influence occurred - and don't laugh, physicists are actually talking and even experimenting with such concepts, but be very quiet about that, because that invokes the "t" word [teleology], and that makes Darwinians and Diracians very nervous, although Cosmic Anthropic Principle-ists will use the word... reluctantly and nervously of course - or whatever evolutionary material that was laying around in the oceans received some sort of myscegenatious "bump" from something from off-planet that suddenly arrived on this planet, and out popped squids and octopuses.
But if none of that is terribly convincing, the following paragraph is an eye-popper:
However consistent with this conclusion are the recent RNA editing transcriptome-wide data on the somatic RNA diversification mechanisms in the behaviourally sophisticated Cephalopods such as Octopus. These data demonstrate extensive evolutionary conserved adenosine to inosine (A-to-I) mRNA editing sites in almost every single protein-coding gene in the behaviorally complex coleoid Cephalopods (Octopus in particular), but not in nautilus (Liscovitch-Brauer et al., 2017). This enormous qualitative difference in Cephalopod protein recoding A-to-I mRNA editing compared to nautilus and other invertebrate and vertebrate animals is striking. Thus in transcriptome-wide screens only 1–3% of Drosophila and human protein coding mRNAs harbour an A-to-I recoding site; and there only about 25 human mRNA messages which contain a conserved A-to-I recoding site across mammals. In Drosophila lineages there are about 65 conserved A-sites in protein coding genes and only a few identified in C. elegans which support the hypothesis that A-to-I RNA editing recoding is mostly either neutral, detrimental, or rarely adaptive (reviewed in Liscovitch-Brauer et al., 2017). Yet in Squid and particularly Octopus it is the norm, with almost every protein coding gene having an evolutionary conserved A-to-I mRNA editing site isoform, resulting in a nonsynonymous amino acid change (Liscovitch-Brauer et al., 2017). This is a virtual qualitative jump in molecular genetic strategy in a supposed smooth and incremental evolutionary lineage - a type of sudden “great leap forward”. Unless all the new genes expressed in the squid/octopus lineages arose from simple mutations of existing genes in either the squid or in other organisms sharing the same habitat, there is surely no way by which this large qualitative transition in A-to-I mRNA editing can be explained by conventional neo-Darwinian processes, even if horizontal gene transfer is allowed. One plausible explanation, in our view, is that the new genes are likely new extraterrestrial imports to Earth - most plausibly as an already coherent group of functioning genes within (say) cryopreserved and matrix protected fertilized Octopus eggs.
Thus the possibility that cryopreserved Squid and/or Octopus eggs, arrived in icy bolides several hundred million years ago should not be discounted (below) as that would be a parsimonious cosmic explanation for the Octopus' sudden emergence on Earth ca. 270 million years ago. (Emphases added)
There is a problem, of course, in the assumption of cryo-genic preservation, for freezing cell-based life, based on water, is a process that actually bursts the cells, and renders "re-animation" - at least to present technology - unattainable. But assuming that nature found some way to do it (and one could easily argue that maybe it has), then the seeding of cephalopods to Earth is certainly possible.
Ok, so what? Where's the high octane speculation in all this?
Well, for that, we'll have to wait until tomorrow, for part two...
See you on the flip side...