Fact Check

Does Octopus DNA Come from Space?

Rsearchers didn't discover that octopus DNA is "alien," or that it originated anywhere but on Earth, although a few have suggested the possibilty.

Published June 19, 2016

Researchers have discovered that octopus genomes contain alien DNA.

In June 2016, a number of web sites reported that, according to recent study, researchers had examined octopus DNA and discovered it was either "alien" or "from space":

The DNA of octopus may not be from this world, scientists revealed. The new study concluded that octopuses actually have alien DNA!

According to the study published in the journal Nature, octopuses have a genome that yields an unprecedented level of complexity, composed of 33,000 protein-coding genes. This number is way beyond the number that can be found in a human being.

Other dubious online site made similar assertions, claiming that the study showed beyond a doubt that octupuses don't come from the planet Earth:

Now, it seems as if aliens always existed amongst us, but we never knew it! If a new study is to be believed, Octopuses are actually aliens!

The study concluded that octopuses have "alien" genes and more probing from the marine biologists can reveal more breakthroughs. The world is still so vast and we only knew half of what is really out there!

A new study has led researchers to conclude that Octopuses (NOT Octopi) have Alien DNA. Their genome shows a never-before-seen level of complexity with a staggering 33,000 protein-coding genes identified, more than in a human being.

US researcher Dr. Clifton Ragsdale, from the University of Chicago, said: The octopus appears to be utterly different from all other animals, even other molluscs, with its eight prehensile arms, its large brain, and its clever problem-solving abilities.

“The late British zoologist Martin Wells said the octopus is an alien. In this sense, then, our paper describes the first sequenced genome from an alien.”

The underlying study did not assert extraterrestrial origins for the octopus, however:

Our analysis suggests that substantial expansion of a handful of gene families, along with extensive remodelling of genome linkage and repetitive content, played a critical role in the evolution of cephalopod morphological innovations, including their large and complex nervous systems.

The study had been published in August 2015, and it was unclear why multiple web sites suddenly picked up and ran with a completely erroneous interpretation of it nearly a year after it first appeared. The "alien" angle seems to have originated with a press release, which (like the study) was published in 2015:

“The octopus appears to be utterly different from all other animals, even other molluscs, with its eight prehensile arms, its large brain and its clever problem-solving capabilities,” said co-senior author Clifton Ragsdale, associate professor in Neurobiology and Organismal Biology and Anatomy at the University of Chicago. “The late British zoologist Martin Wells said the octopus is an alien. In this sense, then, our paper describes the first sequenced genome from an alien.”

It was clear that Ragsdale meant that the octopus was an alien metaphorically, not literally. But, as is often the case, a number of web outlets seized upon the use of the word to spin up stories without first reviewing the source material:

Yesterday, a number of sites started running stories that seemed to imply that octopuses are aliens. As in, from outer space (?). The Yahoo! News headline ran with Octopus genetic code reveals ‘alien creature’; over at the Mirror, they were having a field day with Octopus genetic code is so strange it could be an ALIEN, according to scientists; and the Irish Examiner proudly proclaimed, Don’t freak out, but scientists think octopuses ‘might be aliens’ after DNA study.

The words "alien," "space," or even "Earth" didn't appear in the August 2015 study of octopus gene sequencing. However, a tongue-in-cheek remark made later by one researcher was widely taken out of context to suggest otherwise.

Coincidentally, a controversial paper subsequently published in the March 2018 issue of the journal Progress in Biophysics and Molecular Biology ("Cause of Cambrian Explosion - Terrestrial or Cosmic?") examined whether some aspects of evolutionary theory might be better explained by positing that the precursors of some Earth organisms could have been extraterrestrial in nature. The paper offered an example which suggested -- but did not prove -- that one possible explanation for why octopuses (cephalopods) are very different from their presumed evolutionary ancestors (nautiloids) might be that their genes came "from the cosmos at large":

Some genetic features from recent data in the Octopus and other Cephalopods provide challenging examples to conventional evolutionary thinking.

The genome of the Octopus shows a staggering level of complexity with 33,000 protein-coding genes more than is present in Homo sapiens. 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. 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. 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) 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.

The paper maintained we should not "discount" the notion that octopus genes may have been "extraterrestrial imports" which "arrived in icy bolides several hundred million years ago":

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, as that would be a parsimonious cosmic explanation for the Octopus' sudden emergence on Earth ca. 270 million years ago.

However, the paper also noted that "such an extraterrestrial origin as an explanation of emergence of course runs counter to the prevailing dominant paradigm." And as Ephrat Livni observed in Quartz, other scientists don't necessarily find the paper's ruminations something to be taken seriously:

Virologist Karin Moelling of the Max Planck Institute Molecular Genetics in Berlin isn’t convinced, although she says that the paper is worth contemplating because there’s still so much we don’t know about the origins of life on Earth. She writes in in a commentary in the same publication, “So this article is useful, calling for attention, and it is worth thinking about, yet the main statement about viruses, microbes and even animals coming to us from space, cannot be taken seriously.”

Evolutionary scientist Keith Baverstock from the University of Eastern Finland, in his commentary on the paper, is equally wary. The proposed theories “would support an extra-terrestrial origin of life,” he writes. Still, they don’t necessarily lead to that conclusion; there are other plausible explanations for the evidence the paper offers.


Albertin, Caroline B. et. al.   "The Octopus Genome and the Evolution of Cephalopod Neural and Morphological Novelties."     Nature.   13 August 2015.

Creighton, Jolene.   "Evolution 101: No, an Octopus Is Not an Alien."     Futurism.   13 August 2015.

Danson, Casey Coates.   "Scientists Conclude [Octopus] DNA Is Not from This World."     Global Possibilities.   11 June 2016.

Jiang, Kevin.   "Landmark Sequencing of Octopus Genome Shows Basis for Intelligence, Camouflage."     UChicagoNews.   13 August 2015.

Science World Report.   "Octopuses Are Aliens with Weird DNA and Superpower Capabilities."     13 June 2016.

Zee News.   "Bizarre: Study Compares Octopuses with Aliens for Weird DNA!"     14 June 2016.

Steele, Edward J. et al.   "Cause of Cambrian Explosion - Terrestrial or Cosmic?"     Progress in Biophysics and Molecular Biology.   13 March 2018.

Livni, Ephrat.   "A Controversial Study Has a New Spin on the Otherworldliness of the Octopus."     Quartz.   19 May 2018.

Kim LaCapria is a former writer for Snopes.

David Mikkelson founded the site now known as snopes.com back in 1994.