This month has seen a highly controversial paper by Edward Steele et al, released in the Journal of Progress in Biophysics and Molecular biology, which is suggesting that octopus and squid eggs were delivered to Earth by a meteor and that they are literally aliens from another planet.
Whilst there is potentially some truth that microorganisms might seed life in an otherwise life-less planet by travelling in meteors, this most recent claim seems too fantastical for even the most ardent of optimists.
Cephalopods are a highly derived invertebrates class from the Phyla Mollusca. Their name comes from the ancient Greek kephalo meaning head and poda meaning foot. They are characterised by their soft bodies and high intelligence capacity, especially when compared to their other molluscan cousins. The class first appeared circa 500-600 million years ago with primitive Nautiloids and has since branched out into two main sub-classes.
The first of these are the Coleodia which include the Octopus, Squid and Cuttlefish all of which have many extant representatives and are estimated to have appeared 350 million years ago. The latter are the more ancient Nautiloidea which includes the Nautilus and Allonautilus. This group used to contain many more families like the Ammonites which are sadly extinct.
Nautiloidea are the only sub-class which have properly developed snail like shells. It’s made up of increasingly larger chambers which are filled with gas to give the animal buoyancy, much like a divers BCD. The final chamber is where the animal lives and is the largest of them all. They also have the simplest, pinhole eyes of all the cephalopoda, not that they really need them at the depths they are normally found at. It is their keen sense of smell that they rely on to find food.
All members of this class demonstrate complex problem solving and learning behaviour with the Coleodia showing the highest degree of intelligence. It is an interesting observation that the Coleodia also have the most derived ability to camouflage themselves by changing the colour and texture of their skin. These spectacular colour changes have even been connected with intraspecies communication, something commonly reserved for Cetaceans and Apes. Not bad for a developed snail!
Despite this dependency on colouration patterns it might surprise most to learn that the vast majority of Cephalopods are indeed colour-blind. Their ability to match to environmental colour pallets is derived from special cells which reflect light from their surroundings and not a conscious effort. This explains, in part, why the change can happen so instantaneously too. Depending on the exact species, the pupil is W-shaped, U-shaped or dumbbell shaped. The reason for this strange shape is unknown but work coming out of Harvard University suggests that it allows cephalopods to receive light from many directions. This chromatic aberration has been linked with the ability to perceive colours rather than detect them like humans do.
It is often assumed that Cephalopods only move by wafting their tentacles in a manner resembling a jellyfish, but this is not the whole story. In fact, it was the Cephalopods which actually invented jet propulsion over 485 million years ago and still use this method of movement today. They use it for sudden bursts of speed to evade predators or capture prey. Of all the groups, it is the squid and the cuttlefish which use it to greatest effect reaching estimated speeds of 40km/h in just a few seconds!
With such amazing features spontaneously developing in molluscs it can be tempting to think that there must have been some external influence and indeed this is exactly what the paper is claiming. In fact, alien octopuses is a frightening frequent claim made by many. The philosopher Peter Godfrey-Smith wrote in his book Other Minds that octopus are “the closest we will come to meeting an intelligent alien”.
The first cause for concern is that none of the papers authors are actually zoologists. Further, one might expect there to be some genetic evidence to differentiate Cephalopods from other molluscs. Funnily enough, in 2015, a paper by Caroline Albertine et al released in the Journal of Nature, actually published the Octopus genome demonstrating their molluscan heritage. Yet, headlines claiming alien octopus persist, probably because it helps to sell papers.
But the most interesting aspect of the claim comes back to more scientific work which suggests that many of the building blocks for life actually arrived extra terrestrially. From the initial building blocks evolved more complex life which we see surrounding us today. If the claim is indeed verified, then it raises the obvious hope that our planet is not the only one which has had life externally ‘seeded’. The possibility of finding life outside of our world is certainly an intriguing one but not nearly as captivating as the thought that all life on this planet might indeed be alien in origin.