Could one of Earth’s most intelligent species be an alien, ‘seeded’ on the planet by an interstellar genetic code? Scientists think the clue might be found in the ancient precursor to life, RNA.
This past April, 2018, the peer-reviewed journal Progress in Biophysics and Molecular Biology published a remarkable scientific paper, Cause of the Cambrian Explosion – Terrestrial or Cosmic? With 33 authors from a wide range of reputable universities and research institutes, the paper makes a seemingly incredible that if true, would have the most profound consequences for our understanding of the universe, namely that life, the paper argues, did not originate on the planet Earth.
Like the basics of the human brain that first evolved in the sea, cephalopods – octopuses, squids and nautiluses – “are an island of mental complexity in the sea of invertebrate animals” having developed on a different path from us, “an independent experiment in the evolution of large brains and complex behavior,” says Peter Godfrey-Smith, philosopher of science at the University of Syndey. “If we can make contact with cephalopods as sentient beings, it is not because of a shared history, not because of kinship, but because evolution built minds twice over,” adds Godfrey-Smith. “This is probably the closest we will come to meeting an intelligent alien.”
View Godfrey-Smith video here –“Aliens of the Deep”
Shapeshifting octopuses are scary smart with the amazing power to edit their own bodies. In April last year, researchers found octopuses — and some of their cuttlefish and squid cousins — regularly edit their RNA, an advanced biological ability, they claim, that came from outer space.
Perhaps the most controversial aspect of the new paper concerns the origins of the octopus. The discussion begins, as it so often does in the paper, with some plausible evidence. Cephalopods (the group comprising squid, cuttlefish, nautilus and octopus) have a somewhat confusing evolutionary tree, first appearing in the late Cambrian period and seemingly descending from an ancestral primitive nautiloid.
Of these, the octopus is the most striking, with features, such as a complex nervous system, sophisticated eyes and a capacity for camouflage, that appear quite suddenly in its evolution. The genes necessary for this transformation, the authors suggest, are not present in its ancestry. Thus, they hold that “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.”
Interestingly, the octopus has some real and pervasive biochemical differences from the nautilus, presumably the closest living relative of the former’s ancestor. In particular, there is evidence of extensive changes in the RNA, and thus proteins, found in the neural structures of cephalopods.
These changes have been preserved and are not found to this extent elsewhere in nature, not even in the nautilus. This indicates that a qualitative evolutionary transformation occurred relatively recently and abruptly in behaviorally complex cephalopods. The sheer scale of these changes leads the authors to conclude that it cannot be explained by normal Darwinian evolution.
“One plausible explanation,’ the researchers argue, “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,” write the authors. This would “be a parsimonious cosmic explanation for the octopus’ sudden emergence on Earth [about] 270 million years ago.”
The Cambrian Explosion was a period of time where life on Earth diversified dramatically, and rapidly, which took place shortly after the emergence of retroviruses in our environment. It was especially dramatic for a type of mollusc called a cephalopod. Tentacles reached out from their shells and wove their way into enormous variety of creatures which eventually became the octopus, cuttlefish and squid.
“We believe this coincidence is not fortuitous but is consistent with a key prediction … whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events,” the study’s abstract reads.
This idea is that space-borne retroviruses eventually found their way to the Earth’s surface before attaching themselves to living organisms. Once there, they reprogrammed the creatures’ evolution.
“A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus,” the study reads.
“A third focus concerns the microorganism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space.”
The paper argues the space-based transfer of life was likely on a larger scale than just retroviruses. Whole sets of frozen genetic material were cast about on the stellar winds before reaching our tiny blue dot. “Thus the possibility that cryopreserved squid and/or octopus eggs, arrived in icy bolides several hundred million years ago should not be discounted,” the study reads.
RNA, like DNA, records genetic code. But where DNA is a double-stranded molecule, RNA consists of just one strand. Its role within our body is to transmit genetic information to trigger the production of proteins. But some scientists feel RNA may have been the original DNA, acting as the permanent storehouse of genetic code among Earth’s earliest organisms.
Researchers have found that when it comes to cephalopods like the common squid,up to 60 per cent of the RNA in its nervous system had been edited after it was programmed by DNA. These changes adapted its brain to shifting temperatures in it ocean habitat.
“This shows that high levels of RNA editing … (is) an invention of the coleoid cephalopods,” US Marine Biological Laboratory researcher Joshua Rosenthal said. The central dogma of biology, says Rosenthal, is that genetic information passes faithfully from DNA to RNA before being decoded into proteins. This information can be manipulated at any stage. When done in DNA, the changes are irreversible. Organisms often alter information in RNA because it provides a flexible platform.
Octopus, squid, and cuttlefish are famous for engaging in complex behavior, from unlocking an aquarium tank and escaping to instantaneous skin camouflage to hide from predators. A new study suggests their evolutionary path to neural sophistication includes a novel mechanism: Prolific RNA editing at the expense of evolution in their genomic DNA.
Acknowledged experts are unconvinced by the findings. Avi Loeb, the Frank B. Baird Jr. Professor of Science at Harvard University, told Newsweek the study raised “an interesting but controversial possibility, offering no “indisputable proof” that the Cambrian explosion is the result of panspermia.
Astrobiologist Frances Westall, who is involved in the European Space Agency’s Mars Express mission, is skeptical of the paper. For instance, some microbial cells and seeds, she told Newsweek, have been shown to survive in space for certain periods of time. But in the scenario offered in this paper, they would need to have survived in interstellar space for thousands of years.
Although the chemical building blocks for life may be cosmic, more experimental work needs to be done to probe the origins of life on Earth, Westall said. “Unfortunately it is all too easy to pull information out of the literature to support one’s hypothesis,” she added. “Nature is incredible, and I do not think it is necessary to call on extraterrestrials to explain.
The Daily Galaxy via US Marine Biological Laboratory and CfA
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