contact@onbelief.orgAre there Laws of Biology?
If a science is to become usefully descriptive of the world it would appear that powerful ideas or 'laws' of very general applicability need to be developed. If we are to understand ourselves and our beliefs it would seem that such ideas will need to be grounded in our understanding of biology.
Does biology have laws on which a philosophy of belief would ultimately be based through an integration of reductionist ideas? There are 'laws' of physics and chemistry which are so well established that they are treated as factual (P almost = 1) within their domain of predictive competence. Are there any laws with equivalent certainty relating to the sciences of life that even result in a biological definition of what life is?
Many years ago my Ph.D. supervisor, who had studied physics, asked me this question as I sat at the microscope learning something of embryological development. Thirty years later I find that even defining life is difficult. Consider the inadequacy of the the following list of postulated 'laws of life' concerning earth-bound life forms which is an attempt produce a primitive answer.
Proposed Laws of Biology
1) a thermodynamic law of life: a) Life can only exit in sytems that are not in thermodynamic equilibrium b) All living things must exist in a non-equilibrium state relative to the world outside of their boundaries for part of their life cycle.
2) a law of individuality: All living things must posses a topologically continuous external boundary.
3) a law of boundary condition: All living things must have a boundary different in structure from the external surroundings and the material contained within that boundary. The thermodynamic law of life requires that the boundary of all living things must be semi-permiable.
4) a law of complexity: Large and complex living things must by definition have internal boundaries.
5) a law internal fluidity or aqueousness: All living things must exit is an internally fluid state permitting short range diffusion processes and random spatially and temporally dense molecular interactions. On earth this means all living things must contain contain water. [Since the largest part of the earth's surface is covered in water this is hardly surprising.]
6) a law of minimum elemental composition: There is a minimum set of chemical elements required for life (these might include H, O, C, S, N, P, Cl, Na, K, Fe, Zn, Mg, Mn, etc ).
7) a law of minimum chemical bond set: a result from the law of minimal elemental compositional subsidiary law of a minimum chemical bond set is required for the functioning of life, for example C-C, C=C, C-H, N-H, C-N, O-H etc
8) A law of chemical chirality: Chemical chirality will exist in all life forms for reasons of thermodynamic efficiency
9) a law of minimum molecular complexity: Life cannot exit without the presence of large macromolecules that encode information for replication, catalyze chemical reactions and provide structural integrity [In practice this means that all living things must have macromolecules of nucleic acid, protein lipid and carbohydrate. ]
10) a law of common origin: All existing terrestrial life has a common origin and thus common although divergent biochemistry. In other words the central dogma of molecular biology must apply to all living things. [Clearly that dogma will become more elaborate as molecular biology develops.]
11) a law of ancestry: All living things must have had a living ancestor that possessed self-replicating information systems (after the appearance of life).
12) a probabilistic law of imperfect replication: Some individuals within a species must be capable of reproducing themselves at some time in their life cycle. The fidelity of reproduction at a population level will always be less than perfect.
13) a law of birth: all living organisms must have a starting point in time
14) a law of development: reproduction is not possible without a change in structure and entropy
15) a law of death: Death is the permanent and irretrievable breakdown of the internal or external boundary conditions. Death must occur in all living things.
16) a law of extinction: Combing the law of death with the law of imperfect reproduction we can formulate a subsidiary law that all species presently in existence will become extinct
17) a law of ecological necessity: with the possible exception of Chemoautotrophs no species can exist in isolation.
On the Nature of Belief
www.onbelief.org
Scotland, 12th October 2007 and thereafter
Copyright 2007 onwards
