While this is a review of the work of Jose Diez Faixat, it will start with a wider overview of the evolutionary model, such that we might be better positioned to evaluate the author’s ideas. We might start by accepting that there is clearly an aspect of biological life that science does not yet fully understand. We might raise the obvious question as to ‘how’ life began and then move towards more philosophical issues surrounding the ‘why’ questions. Of course, such questions possibly assume that we can accurately define a living system and whether any of these living systems has a wider purpose in the totality of the universe. While the answers to such questions are obviously speculative, there are accepted ideas, such as Darwinian evolution, biology and genetics, which science believes provide insights to some of the causal mechanisms at work.
Note: While the questions above might be considered as broadly scientific in scope, it must be recognized that such issues have also been debated over all human history in terms of both religious beliefs and philosophical conjecture. However, what this discussion will assert from the outset is that neither science, philosophy or theology can proceed with certainty in their assumptions.
While the caveat in the note above applies equally to science, it will be argued that science, in principle, requires empirical verification of what it assumes to be factual, which is often missing in a philosophical conjecture or religious belief. As such, this introduction will now proceed on outlining some basic scientific assumptions, which may shed some light on the questions, if not definitive answers. We might start with a very generalized and possibly overly abstract definition of a living system, as opposed to a non-living system.
A living system is a self-contained, self-organised and non-equilibrium system, which is governed by an internal genetic program that can reproduce itself.
While science proceeds on the assumption that a living system is still subject to the laws of physics, when made of atoms and molecules, we might consider these ‘laws’ in terms of physical chemistry, which can also apply to non-living systems. As such, we need to proceed from fundamental physics towards molecular chemistry and consider the thermodynamic mechanisms at work within these systems. However, living systems, unlike non-living systems, appear to have evolved in terms of an increasingly complex hierarchy of different functions, e.g. replication, adaptation, reproduction, which took place within a cause and effect framework. These functions continued to evolve in terms of a myriad of complex symbiotic relationships, which even from the start is assumed to have been subject to natural selection, where life appears to have acquired a form of collective purpose greater than the sum of it biological parts.
Note: While only a speculative summation of multiple evolutionary mechanisms, somewhere in a process of functional aggregation, life emerged as a living cell, where organic chemistry was distinct from inorganic chemistry. By way of a crude distinction, inorganic chemistry deals with the study of inorganic compounds, i.e. compounds that are not carbon-based.
While accepting the simplicity of this introduction, evolution might initially be described as proceeding on three mechanisms described as mutation, gene flow and genetic drift. In this model, mutation creates new genetic variation in a gene pool, while gene flow and genetic drift are also subject to natural selection, i.e. survival. As this is a very generalised description, the three mechanisms cited possibly need some further outline.
- Mutation can create new genetic variations in a gene pool and give
rise to new alleles. However, for any given
gene in the
genetic code, the chance of a mutation successfully occurring is relatively
- On longer timescales, gene flow is a process linked to genetic
changes in the make-up of a population. If the rate of migration is
high, this can have a significant effect on allele propagation.
- As described, genetic drift is still a somewhat random change in the genetic makeup in a small population. However, when a small number of parents produce just a few offspring, genetic change may persist and propagate.
It might also be highlighted that there are two generalised conditions under which genetic drift occurs. The first is a ‘bottleneck effect’ caused by a reduction in the population, possibly due to some natural disaster, after which the surviving population is genetically different. The second is referred to as a ‘founder effect’ linked to migration of a population, which over time becomes increasingly genetically different to the original population. Without being too rigorous, as there are undoubtedly a multitude of potential causal factors driving evolution, we might still see how a general process of natural selection might lead to genetic change that helped the survival of some populations in different environments.