Download Octopuses have always amazed the world with their intelligent

Octopuses have always amazed the world with their intelligent behavior, unique
colorations to adapt to the background, and the way they manage their flexible arms
without getting them entangled. The octopus is an example of advanced cognitive
adaptation, but how its brain (see the yellow part in picture below) works still
remains a mystery.
The octopus brain does not look at all like brains of other animals. Is has a huge optic
lobe underneath their eyes and a highly developed touch system which explains their
excellent eye sight and sense of touch. It has two memory systems that follow these
two sensory systems: a visual and an tactile memory used to identify signals in the
environment for attack or retreat. And to explore novel situations.
Anatomy of the octopus
But most amazing is how
the octopus controls its
eight arms. Its nervous
system contains 500
million neurons. But
two-thirds of these nerve
cells are located in the
nerve cords of its arms
(see yellow extensions in
picture), which makes
the eight tentacles function as an extended brain. The central brain only has to trigger
a command to the arms, which then carry out the full action sequence. Suggesting
that the entire movement plan is embedded in the arm itself and not in the central
brain like in mammals. There is no proprioception, that is neural feedback paths of
their movements to the brain, so movements must be monitored by 'seeing what
happens'
Octopus evolution Peter Godfrey-Smith a philosopher of science and experienced
scuba diver became fascinated by the octopus and expressed some interesting views
on this creature in his recent and captivating book*. Why has the octopus followed
such a strange route of evolution, completely different from that of birds and
mammals? Cephalopods, the family to which the octopus belongs have a history of
half a billion year of evolution. Their ancestor started as a mollusk that gradually
transformed itself via various stages into the three common species of today’s world:
the Nautilus, the Cuttlefish and the Octopus. The early species lived on the seafloor,
later came development of the arms to lift themselves from the seafloor.
Camerosceras is one of the spectacular intermediate stages; this was a large
predatory cephalopod with an estimated length of 18 feet (see figure below). Early
now extinct versions still had shells but newer forms gave op their shells, with
Nautilus as an exception.
Some important steps in the the
evolution of the cephalopods
(adapted from Peter Godfrey-Smith
(2016)).*
An amazing fact of the octopus is
that this smart and complex
creature has no skeleton and
hard parts at all. This allows it
to change the form and size of its
body, for example to squeeze
itself through narrow holes of
only a few centimeters wide. As
said earlier, unlike brains of
vertebrates the octopus has no
central brain that controls the
limbs. The octopus arms are in fact its brain. A term used by some scientists is
embodied cognition: our body itself is responsible, rather than our brain, for some of
the smartness with which we handle the world.** This raises the question of
consciousness, that bugged the mind of philosophers since ancient times, and who
believe that consciousness is uniquely human. Unlike many philosophers modern
scientists take an different point of view. For example primate biologist Frans de
Waal of the Yerkes Institute believes that intelligence and consciousness are not
uniquely tied to humans. So does diver-philosopher Godfrey-Smith who poses the
question: what about consciousness in the octopus? Since its arms are its brain but
alto also its agents or instruments, the octopus must be in a sort of hybrid situation.
Its arms are partly self but also partly non-self: agents of their own.
Octopus intelligence Perhaps animal intelligence and consciousness become less
of a puzzle if we accept that intelligent behavior evolved in man as well as animal in
different forms dependent on the demands of their specific environments. Think of
the tree of life with a common ancestor but with various branches leading to unique
and clever adaptations of even non-mammalian species. In the octopus intelligence
is largely a ‘grasp, explore and sense’ intelligence. They do not use their intelligence
for maintaining complex social interactions like humans and chimpanzees. But
they do have a highly exploratory and opportunistic style of interaction in their
watery environment. Octopi are clever, not because they share a common ancestor
with mammals and humans, but because they followed a completely separate
evolutionary branch than ours. So genetically, meeting an octopus is indeed like
meeting an intelligent alien.
Octopi held in captivity have the reputation of mischief and escape. They have been
seen to escape from their own aquarium, to walk around on the floor of the room en
and even to visit a neighboring tank for food. There is even the story of an octopus
squirting jets of waters against a lamp short circuiting the power supply, or against
visitors of its tank! These anecdotes suggest that the octopus may adapt easily to its
environment and even its human keepers. Unlike fishes they seem to have developed
a sense that they are inside, and their visitor outside the tank. They are also able to
use new objects for their safety. In 2009 researchers in Indonesia were amazed to see
octopi carrying around half coconut shells over the sea floor to use as portable
shelters. Octopuses in the sea are also known to use their arms in battles, by hurling
sand and debris to its rivals. Getting to know the octopus makes it hard to accept
that this superb creature is still hunted down to end up in sea food dishes all over the
world.
Sources and links
J. Z. Young. "The Anatomy of the Nervous System of Octopus Vulgaris" Oxford University
Press. N.Y. (1971)
*Peter Godfrey-Smith. Harper. Other Minds. The octopus and the evolution of intelligent life.
Collins Publisher.London (2016)
**Hillal Chiel and Randall Beer (1997). The Brain has a a Body: Adaptive Behavior Emerges
fro Interavtions of Nervous System, Body and Enviroment. Trens in Neroscinec 23
(1997):553:57
http://cephalove.blogspot.nl/2010/06/view-of-octopus-brain.html
http://www.dailymail.co.uk/sciencetech/article-3214442/Octopuses-fire-Cephalopods-seenhurl-shells-debris-rivals-fights-protect-territory.html