These are excerpts and elaborations from my book "The Nature of Consciousness"
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Protoconsciousness The US psychologist Stuart
Hameroff advanced a theory of consciousness rooted in Physics,
notably in Roger Penrose's ideas about objective reduction.
One of the
big mysteries of evolutionary Biology is the sudden explosion of species during
the Cambrian period. According to fossil records, life on Earth originated
about 4 billion years ago, but for about 3.5 billion years it evolved very
slowly, producing mainly single-celled organisms and a few simple multicellular
organisms. Then, all of a sudden, in a rather brief period of 10 million years
beginning about 540 million years ago (the Cambrian period), a huge number of
different forms of life emerged. Biologists have always been puzzled by this
sudden diversification of life. One possible explanation
would be the emergence of a feature that greatly enhanced adaptation and
mutation. Hameroff thinks that it may have been the emergence of consciousness,
that consciousness not only occurred early in the evolutionary path but it even
altered the course of evolution. The idea is that behavior can indirectly alter
genetic information, as already argued in 1958 by the Austrian
physicist Erwin Schroedinger, by enabling organisms to survive and reproduce where non-intelligent
organisms would simply die. Cells contain a structure
called cytoskeleton, which is made of a protein called "tubulin", which
forms cylinders called "microtubules". According to the US biologist
Lynn Margulis, microtubules and the
cytoskeleton were created by symbiotic mergers more than a billion years ago.
Simple organisms actually had to rely on the cytoskeleton for purposeful
behavior. Having no synapses or neural networks, they relied on their
cytoskeleton for sensation, locomotion and information processing. Cytoskeletal
structures provided several services, including internal organization of the neuron,
processing of information, communication. In summary, the cytoskeleton
organizes intelligent behavior in simple organisms. Margulis thinks that consciousness was a
property of even simple unicellular organisms of several billion years ago. The cytoskeleton seems to
play a particularly relevant role in differentiation. A cell's genes are
activated and regulated by its cytoskeleton. Cytoskeletal cooperation among
neighboring cells enabled differentiation and allowed different types of
tissues to emerge. Then, higher order structures appearing with specific
functions (organs) started appearing and these in turn enabled more purposeful
behavior. All of this depends on the
cytoskeleton, which Hameroff thinks is the level at which consciousness is
created. If that is the case, then rudimentary "conscious" events
occurred the very moment the cytoskeleton became important for small organisms.
Organisms began to experience feelings and make conscious choices. Back to the beginning of the chapter "A History of Consciousness" | Back to the index of all chapters |
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