Piero Scaruffi(Copyright © 2013 Piero Scaruffi | Legal restrictions )
These are excerpts and elaborations from my book "The Nature of Consciousness"
The Origin of Form
In the 1890s, the German physiologist August Weismann realized that living organisms exhibit a dichotomy: a piece of the organism's machine is designed to reproduce and another piece is designed to achieve form. One needs both in order to specify an organism.
In a sense, Weismann was the Descartes of biology: he separated reproduction and "soma" (form), genetics and morphogenesis. So one can study genetics without studying development, and viceversa. He understood that the problem has to be reframed in terms of "information”.
One of the most puzzling features of life is, indeed, development. During development, cells split and split and split. Every time a cell splits, the new cells inherit (almost) exactly the same genes. But then, mysteriously, some cells become liver cells and some cells become bone cells and some cells become blood cells. Somehow a cell knows which proteins it has to make, and when and how many of it. If they run the same program, how come that two cells become two different things? And how do they know the position where those two things have to be?
Not surprisingly, Weismann concluded, logically, that each cell must include a different set of genes. We have, instead, learned that each cell includes the same set of genes, but a cell's genes are "regulated" in such a manner that only some are active. Each cell has the same set of genes, but each cell has different genes active. Nonetheless, the question remains: what determines which genes are switched on and off in a given cell? How do "regulatory" genes know that a cell has to become part of a hair rather than a liver? Whatever the mechanism, it must be extremely reliable, because billions of humans get eyes in their face and not in their feet. Even more striking is the fact that zebras have black and white stripes: how do those cells know that they have to be white or black? And what causes the skin of the zebra to have stripes, rather than a uniform color? (The British mathematician Alan Turing proposed a solution based on the properties of standing waves)
The British biologist D'Arcy Thompson argued that genetic information alone does not fully specify form. Form is due to the action of the environment (natural forces) and to mathematical laws. Form arises because of mathematical and physical properties of living matter, just like the shape of nonliving matter. Form is a mathematical problem, and growth is a physical problem. The form of an object is a resultant of forces. By simply observing the object, we can deduce the forces that have acted or are acting on it. This is easily proved of a gas or a liquid, whose shape is due to the forces that "contain it", but it is also true of solid objects like rocks and car bodies, whose shapes are due to forces that were applied to them.
The formative power of natural forces expresses itself in different ways depending on the "scale" of the organism. Mammals live in a world that is dominated by gravity. Bacteria live in a world where gravity is hardly visible but chemical and electrical properties are significant.
Ultimately, D'Arcy believed that living organisms owe their form to a combination of internal forces of molecular cohesion, electrical or chemical interaction with adjacent matter, and global forces like gravity.
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