42. A Gibbs-Duhem equation for natural selection

Since a sound mathematical model can be looked at in a variety of different ways, our interdependent intensive and extensive variables also allow us to present a biological version of a standard Gibbs-Duhem style equation:

µ

=

dS

=

dU

+

dH

-

Σiµi(dvi - dmi)

         

Essential development, λ

Compensatory development, L

1. Probundance, γ

2. Procreativity, ψ

3. Accreativity, Y; and 4. Abundance, C

Both dU and dH again reflect the probundance, γ, and the procreativity, ψ, respectively, of essential development, λ, these being properties of the entire population rather than of any given entity and such that λ = γ + ψ. These are the changes in the population’s stock of biological matter, U, and energy, H, when the numbers hold constant … and so when µ = dS = dU + dH = λ = γ + ψ and the remaining summation term for compensatory development is zero.

We can now specifically consider, say, all variables and variations associated with the ith entity in any population. Its specific effects on our population are given by its specific biological potential or apportionment tendency regarding its own mass and energy:

µi = (U/mi)V,S,N - (U/vi)m_,S,N.

This states that if we hold the visible presence, the engeny, and the numbers over the rest of the population constant, and infinitesimally increment the number of components introduced because of i; and/or hold the average number of components per entity, the engeny, and the numbers for the population constant and then infinitesimally increase is visible presence by introducing it; then we will state all the energy changes caused by this ith entity … including its insertion into or extraction from any population. And … this is exactly the effect we need to quantify natural selection and Darwinian competition and evolution.

This biological potential, µ—and which we can measure in watts—is now the motive force for the biological cycle. It is responsible for any energy flux. It suitably partitions itself amongst its three different factors and to affect both the entire population and its individual entities. Therefore … the energy change inhering to every biological entity in any and all biological systems is measurable and determinable … as also is any change that could be conjectured under the constraint that N has remained constant and that all terms due to all distinct is or separate entities have been either ignored or considered. We can in other words test Darwinain competition against predictions made both with and without it; take measurements; compare the measurements to our predictions; and then draw appropriate conclusions.

We can now state simply and clearly that if competition, natural selection, and Darwinian evolution do not exist, then all terms declaring a compensatory development, L, in our above two equations will sum to zero. That is to say, the two terms Σi(S/ui)U,V,{Nj=/i} and dui, Σi(S/vi)U,V,{Nj=/i} dvi from our first equation, and Σiµi(dvi - dmi) from the second—being the abundance, C, and the accreativity, Y— must again all be zero. They are called the compensatory development, L, precisely because they are the biological inductions proposed by Darwin and that can only occur in response to the changes in numbers that he proposed, as members are lost to the environment and regained in reproduction, for those measurable biological inductions are an explicit effort to preserve the species and the population through compensatory changes in all remaining entities.

Recent Posts

Walls, energy, and a Centre for Biology

Let us consider the following apparently definitive declaration made by the Centre for Mathematical Biology, Oxford University: “You can’t compare a living organism to a heat pump”. But … is this really true?

  Read more ...
The more they remain the same the more they change

John Ray, the English naturalist and scientist, produced the first ever biologically-relevant definition of ‘species’. He was trying to classify plants and in 1686 wrote: In order that an inventory of plants may be begun and a classification (divisio) of them correctly established, we must try to discover criteria of some sort for distinguishing what [...]

  Read more ...
Can we escape evolution?

Although the word ‘constraint’ often has a negative connotation in ordinary language, it is how scientists and mathematicians operate. One of the first and most effective uses of a scientific-mathematical constraint came in the seventeenth centruy from the Frenchman Pierre de Fermat (of ‘Fermat’s last theorem’ fame). Natural philosophers of his day wondered what path [...]

  Read more ...
Geography and the Gibbs energy

The ‘Gibbs energy’ is invariably difficult to explain to those who don’t know what it is. And despite its importance, it was only at the end of the nineteenth century that Max Rubner, the German physicist and physiologist, at last convinced other scientists that the energy that biological organisms use in metabolic processes exactly equals [...]

  Read more ...
Circumambulations: what are they, and why are they relevant to biology?

So what is a circumambulation, and why is it relevant to biology and evolution? Brian Charlesworth wrote in his book Evolution in age-structured populations (Cambridge University Press, 1994) that: “… the concept of generation time is a rather arbitrary one”. He then lists several alternatives. It is surely rather strange that something so fundamental to [...]

  Read more ...

Comments or queries

Please click here to go to the comments page if you wish to make a comment or raise a query regarding anything in this section. Your comement or query will appear here. If necessary, someone will also respond and answer as soon as possible. (In order to prevent ‘comment spam’, your first comment must be approved by a moderator. Once approved, your subsequent comments or queries will appear here immediately).

 

Recent tweets