Piero Scaruffi(Copyright © 2013 Piero Scaruffi | Legal restrictions )
These are excerpts and elaborations from my book "The Nature of Consciousness"
A body is made of cells. Every single cell in the same body contains roughly the same genetic information (barring copying mistakes). However, each cell ends up specializing in a task, depending on where it is located: a heart cell will specialize in heart issues and not, say, liver issues, even though the genetic information describes both sets of issues. A muscle cell is a muscle cell, even though it is identical to a liver cell. This is the phenomenon of "cell differentiation", by which each cell "expresses" only some of the genes in the genome, i.e. only some of the possible proteins are manufactured ("synthesized").
The human body has about 265 different cell types.
Differentiation seems to be regulated by topology: depending on where a cell is, it exchanges energy (which is information) with some cells rather than others. Neighboring cells "self-organize". How cells develop to be what they will be within the body is probably determined by a regulatory mechanism: instead of each cell being "told" by the genes what to become, cells interact among themselves; and the body is the emergent outcome of their interaction. This is an efficient way to produce complex bodies: the genome does not need to specify where each of the 100 trillion cells must go. The difference between humans and chimps is caused by a mere 1.6% of the genome: it is the interactions among cells that greatly amplify that 1.6%. Another advantage is that the body can repair itself: if a cell is damaged, interaction among cells yields a new configuration that makes that damage irrelevant. The price that the organism pays is a long period of "incubation" during which the body “develops” (and it is vulnerable).
A puzzling feature of genomes is that they contain far more useless junk than useful genes. The human genome, in particular, contains about 95% junk, in between genes.
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