Octopuses, those mesmerizing masters of camouflage and escape, have long captivated scientists and nature enthusiasts alike with their remarkable intelligence. But just how smart are octopuses compared to humans? A groundbreaking new study is shedding light on this question by exploring a fascinating genetic link that octopuses share with us – “jumping genes.” This genetic quirk, also found in humans, may partially explain the sophisticated smarts of these brainy cephalopods.
These “jumping genes,” scientifically known as transposons, are short DNA sequences with a unique ability to move around the genome. Intriguingly, transposons constitute a significant portion of the human genome – around 45%. These mobile genetic elements can copy and paste, or cut and paste themselves into different genomic locations and have been recognized for their role in genome evolution across various species. Recent genetic sequencing efforts have revealed that octopuses, specifically the common octopus (Octopus vulgaris) and the California two-spot octopus (Octopus bimaculoides), also possess genomes rich in transposons, according to research published in BMC Biology.
While most transposons in both humans and octopuses remain dormant, rendered inactive by mutations or cellular defense mechanisms, a particular type called Long Interspersed Nuclear Elements, or LINE, stands out. In humans, LINE jumping genes are believed to be actively regulated within the brain and are considered crucial for learning processes and the formation of memories, particularly within the hippocampus.
Delving deeper into the octopus genome, scientists discovered active transposons belonging to the LINE family. These active LINE elements were found in the vertical lobe of the octopus brain. This region is remarkably significant as it’s the octopus’s learning and memory center, functionally analogous to the hippocampus in the human brain. Graziano Fiorito, a biologist at the Anton Dohrn Zoological Station (SZAD) in Italy and co-author of the study, highlighted this analogy in his statements to Live Science, emphasizing the parallel functional roles despite the evolutionary distance between cephalopods and mammals.
To further validate their findings, researchers measured the transcription of an octopus transposon into RNA and its subsequent translation into protein. The results were compelling, revealing significant activity in brain areas associated with behavioral plasticity. Behavioral plasticity, in essence, is the ability of an organism to modify its behavior in response to environmental changes and stimuli. Giovanna Ponte, a researcher at SZAD and another co-author, described this finding as a crucial “proof” supporting the link between jumping genes and octopus intelligence.
Despite the vast evolutionary gulf separating octopuses from vertebrates, their capacity for behavioral and neural plasticity mirrors that of mammals. Fiorito emphasizes that octopuses, much like mammals, demonstrate a remarkable ability to continuously adapt and solve complex problems. This new genetic evidence suggests that this similarity in cognitive capabilities might have roots at the genetic level, hinting at convergent evolution.
This research not only strengthens the connection between jumping genes and octopus intelligence but also proposes that LINE transposons play a more active role than simply moving around the genome. The study authors suggest that these genes are likely involved in higher-level cognitive processing. Given that both humans and octopuses share these jumping genes, they become promising candidates for future investigations into the fundamental mechanisms of intelligence. Understanding how these genes contribute to the development and variation of intelligence within and across species could unlock deeper insights into the very nature of cognitive abilities.
However, the researchers also point out a critical nuance. Considering the significant evolutionary distance between humans and octopuses, the presence of active LINE transposons in both lineages might be a striking example of convergent evolution. This implies that the contribution of these jumping genes to intelligence may have evolved independently in these two distinct branches of life, rather than being inherited from a common ancestor. This possibility further underscores the remarkable and potentially independent paths to complex intelligence that nature has forged.
Originally published on Live Science.
