It is important to understand that entropy measures the information needed to describe the system, while information that we have in the genes, for instance, represents negative entropy—because the information is available. As negative entropy does not exist, we have to introduce another concept. It is the concept of exergy, which will be introduced in the next chapter. The relationship between information and entropy, introduced with Boltzmann's famous equation, makes it understandable that Shannon's expression for biodiversity is strongly related to the entropy expression.
The relationship between biodiversity and stability is rather complex and not straightforward as previously believed in ecology. However, higher biodiversity means that a wider spectrum of properties is available for survival under changing conditions; therefore, higher biodiversity implies a wider spectrum of buffer capacities and type of resistances against changes.
Many distributions in ecology follow Boltzmann's distribution, which is consistent with the power law (Bak, 1996) for self-organising critical systems. It has been shown that several distributions in Nature—the deviation from an average situation, the spatial distribution of species—follow the power law (J0rgensen et al., 1998). It is interesting that the Boltzmann's distribution also explains why a more favourable situation implies that the number of large individuals increases and the number of small individuals decreases.
It is shown that the biosphere is a highly probable consequence of the right temperature, the presence of the elements needed for construction of living matter and sufficient time. Thermodynamically, it is not a puzzle that the biosphere exists, because Earth has the elements necessary for construction of life, has the right temperature, as also discussed in Chapter 3, and Earth has now existed for more than 4.5 billion years!
When the information hidden in the number of species or in the distribution of different biomes is analysed, it is possible to show that the observed patterns in Nature have a high probability. The high number of species (probably close to 107—it was shown that the number would probably be close to 3 X 106 at present; we know approximately this number of species, but it is presumed that there is the same number of still unknown species) or the number and distribution of biomes is a consequence of their properties, the long time and the time arrow.
The amount of information in the genes is astronomically big because not only the number of amino acids, but also the sequences of these amino acids determine the life processes. It is, in principle, not different from a book, where the sequence of the letters is important and carries the information—not just the number of letters. Earlier in the chapter, Blumenfeld's estimations are far too modest. In addition, the genes contain even more information than just about the amino acid sequence, namely, about the "management" of this information, which becomes increasingly more complicated with the increasing complexity of the organisms (Taft et al., submitted). This implies that organisms have a high content of information that can be translated to free energy and exergy, as we shall see in the next chapters. This makes it understandable that ecosystems cannot be easily replaced—ecosystem conservation is therefore urgently needed in environmental management context. When an ecosystem is lost, an enormous amount of entropy is produced due to the loss of the huge amount of stored information in ecosystems.
Bak, P., 1996. How Nature Works. Springer, New York, 212 pp.
J0rgensen, S.E., Mejer, H., Nielsen, S.N., 1998. Ecosystem as self-organizing critical systems. Ecol. Model. 111, 261-268.
Taft, R.J., Mattrick, J.S., Andrew, P.S. Genome-wide increases in non-coding DNA positively correlate with increasing biological complexity (submitted for publication).
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