Subject of the first two chapters was intentionality (‘aboutness’, the being-contained of a content in a physical form or structure) and information processing, both assumed to be properties of structured matter in general . In this chapter, I will try to explain why living beings, even relatively simple organisms, are able to understand information in a semantic sense. I will defend the position that living beings, and only they, are able to transform information into meaning, into signals, and into digital data.
Life, from the perspective of physics, is not very interesting. Looking at the four fundamental forces of physics – strong and weak nuclear force, gravitation, and electromagnetism – , the first two forces don’t play any role in chemical and biological processes. Gravitation is of some importance: When living things went ashore and began to spread on land, they were required to cope with gravitation, and the diversity of forms of terrestrial plants and animals, birds and insects resulted in part from several strategies of ‘outsmarting’ gravitation: Plants grow upwards, animals move freely in balance, or fly despite gravitation. But the effect of gravitation on life seems to be rather external, it is not the force driving life from inside.
So only one fundamental force of physics is left for being the driving force in living things: electromagnetism. And hence life is not very interesting from the view of physics: It is nothing than electromagnetic interaction, anything but exciting! Apparently, the complexity of biological processes does not result from its driving force, but from something else: from the spatio-temporal organization of these processes which are ensured by biological forms and structures, e.g., by the cellular membrane system or by the spacial shapes of proteins.
From the view of physics, we can refer to all these forms and structeres that limit and direct the physical and chemical processes in a living thing as ‘boundary conditions’. From the view of biology, however, these boundary conditions are essential: It is just their spatio-temporal organization which ensures that physical force causes the reproduction of just these steering forms and structures so that they grow and multiply. It’s an interaction between forms and structures, on one hand, and processes, on the other hand, and since forms and structures are information, it is always the effect and the processing of information.
Protein synthesis on the basis of DNA information might he most famous instance of information processing in living things. Sometimes it has been said genetic information entails the bauplan (the blueprint) of a living organism, and I have often wondered how that can be: A plant or animal is a highly complex three-dimensional form, all parts of an animal, like bones, organs, blood- and nervous system have complicated three-d forms – DNA information, by contrast, is only one-dimensional, it’s an only linear sequence of triplets of nucleotide bases coding a linear chain of amino acids, not more .
The sequence of nucleotide bases in the DNA determines the spatial shape of a protein molecule mainly by determining which amino acids are neighbors in a chain. From this it depends whether neighboring amino acids are chemically bounded to each other at one, two, or three points. If bounded only at one point, they can freely move and rotate against one another as coupled with a ball joint; if bounded at two points, they can move against one another in only one plane as coupled with a hinge; if bounded at three points, they are coupled in a rigid manner.
So the neighborhoods determine how freely the chain molecule can move at each juncture. Naturally, it does not actively move, but is moved by the pedesis in the cytoplasm. The molecule undergoes various occasional preliminary shapes before it eventually finds its stable spatial shape. This shape is determined (i) by the spatial shapes of the single amino acid molecules, (ii) by their electromagnetic properties leading to various kinds of interactions between the amino acids of a chain: ionic, polar, and van der Waals interaction, hydrogen bridges, and hydrophilic or hydrophobic behavior. For example, neighboring hydrophobic amino acids will closely appose if their mobility allows such that as less water as possible remains between them. By contrast, two neighboring hydrophilic amino acids will let a distance between each other.
A certain linear order of amino acids in a protein chain has thus consequences that in turn cause the spatial shape of the protein molecule – and the spatial shape is crucial for the molecule’s function in the cell. It seems therefore as if the knowledge of the future shape and function already encoded in the DNA molecule. But how to understand this as long as we don’t believe the DNA sequence was formed by an intelligent designer? Can we assume that the DNA has a knowledge of the properties of amino acids and of the encoded protein molecule’s function? What is ‘knowledge’?
If humans or other living things mostly behave ‘right’ or appropriately in a given situation so that they accomplish their goals or at least avoid harm and death , then we assume that they possess a certain kind of knowledge enabling them to behave in this way. I assume that my knowledge is represented in my brain in the form of neuronal structures (e.g., interconnections, synaptic states), thus these structures are the basis of my ‘right’ behaviors.
Knowledge, however, is structurally stored not only in my brain. Almost all forms and structures in my body – from the large forms of bones, muscles, internal organs, blood circulation and nervous system right down to the microscopic forms and structures of cells and macromolecules – represent knowledge about how all these components need to be formed and structured to fulfill their functions in the organism.
So it seems as if there is a general relation between structure and knowledge in living things: Almost all components are formed and structured appropriately for their functions . Such a relation between structure and knowledge exists also in machines, but here it is the engineer, an ‘intelligent designer’ who knows how to form the components so that they can fulfill their purposes.
If we, however, ascribe knowledge to something that, because of its form or structure, behaves in a way so that it fulfills a function or accomplishes a goal, then we must ascribe knowledge also to the DNA: It behaves ‘right’ because of its structure by supporting (catalyzing) the synthesis of just those chains of amino acids which then fold to the proteins that fulfill their functions in the cell .
Those proteins, with their structures, spatial shapes, and functions, are then the basis on which the macrostructures of a multicellular organism, e.g., of a human body can grow. All the anticipatory knowledge needed for this seems to be contained in the DNA – even if it is not a bauplan, but rather a program for self-organizing development. But how did all the knowledge come into the DNA – given that it was not formed by an intelligent designer?
Before we will address this question in the next section, let us summarize: We want to refer to as ‘knowledge’ that kind of information, i.e., of form or structure that enables a thing or system to fulfill purposes or to accomplish goals.
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