the octopus and the evolution of intelligent life

MicroRNAs were first reported in 1993 by Victor Ambros, a professor at Dartmouth from 1992-2007 who is now a professor at the University of Massachusetts Medical School. This was a big moment - we discovered the secret to complex life, and the secret to complex life is microRNAs.' 'This was always a big test for the hypothesis, that it is not specific to vertebrates. 'This is the only instance in all of the invertebrates of dramatic microRNA increase and those genes are all expressed in the brain,' he said. 'MicroRNAs are known as the 'dark matter' of the animal genome - they don't make protein, but they regulate the expression of proteins,' Peterson said, referring to the hypothetical form of matter thought to constitute most of the universe. Yet, the prevalence of microRNAs in both octopuses and vertebrates suggest a common role for the molecules in advanced cognition. The nervous systems of octopuses and squids - which both belong to a type of mollusk known as cephalopods - evolved independently of vertebrates.

When combined with the known intelligence of octopuses, the findings provide crucial support for the theory that microRNAs are key to the evolution of intelligent life, said co-corresponding author Kevin Peterson, a Dartmouth professor of biological sciences. The genes of two octopus species show an increase in microRNAs - which are linked to the development of advanced cells with specific functions - over evolutionary time that has so far only been found in humans, mammals and other vertebrates. An international team led by researchers at Dartmouth College and the Max Delbrück Center (MDC) in Germany report in the journal Science Advancesthat octopuses are the first known invertebrates - creatures that lack a backbone and constitute roughly 95% of animal species - to contain a high number of gene-regulating molecules known as microRNAs.

The octopus and the evolution of intelligent life