Scientists have already proven that octopuses are more intelligent than ordinary invertebrates, but a new discovery points to one reason: a specific molecular similarity to the human brain.
Both the human genome and the octopus genome contain a large number of ‘jump genes’ or transposons, which are able to replicate themselves or move around the genome. While not all of them are active, these transposons are seen as raw materials for evolutionary processes.
In a new study, transposons belonging to the LINE (Long Scattered Nuclear Elements) family have been discovered in the part of the octopus’ brain that deals with cognitive abilities – a similar place they can be found in the human brain.
“I actually jumped up on the chair when I saw, under the microscope, a very strong indication of the activity of this element in the head lobe, which is the structure of the brain that in the octopus is the seat of learning and cognitive abilities, just like the hippocampus in humans,” Biologist Giovanna Ponti says: From the Research Institute Stazione Zoologica Anton Dohrn in Italy.
Recent Research revealed how carefully LINE transposons are organized in the human brain, and the thinking is that they are linked to learning and memory – in part because they are more active in the hippocampus, where learning processes are controlled.
By finding these jumping genes in the same place in the brains of two species of octopus – the common octopus (common octopusand the Californian octopusoctopus bimaculoides) – Researchers believe they may have found a key reason behind the high intelligence these marine creatures displayed.
While transposons are known to use molecular copy-and-paste and cut-and-paste mechanisms, the study suggests there’s more going on here—that there is a direct relationship to the complexity of the nervous system, including the brain.
“The discovery of an element of the LINE family, active in the brain of the two species of octopus, is extremely important because it adds support to the idea that these elements have a specific function beyond copying and pasting,” Computational genomics scientist Remo Sanges says: From the International Institute for Research in Advanced Studies in Italy.
Furthermore, the researchers believe we can look at an example of convergent evolution: when similar traits evolve independently in completely unrelated species, and provide the same adaptation, in this case superior cognitive abilities.
Scientists continue to find the evolutionary tricks and neural responses that make octopuses stand out among invertebrates, and make them more like mammals in terms of brain structure and activity.
“The octopus brain is functionally similar in many of its characteristics to the mammalian brain,” Biologist Graziano Fiorito says: From the Anton Dohern Zoological Station.
“Also for this reason, the LINE specific element represents a very interesting candidate to study to improve our knowledge of the evolution of intelligence.”
The search was published in BMC Biology.
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