The polarized debate between Richard Dawkins forceful advocacy of Darwinian theory and the religious Christian belief in intelligent design has left little room for alternative theories of evolution. Evolution - the adaptation of species to their natural environment - does take place; as a phenomenon it is not up for debate. The phenomenon of evolution is as close to fact as science can provide us with facts based on evidence. Without the science, we would not have the technological civilization that we enjoy today.
But what is up for debate is the process by which evolution takes place. Since Charles Darwin, the most commonly taught theory is the process of natural selection (along with sexual selection, which we will come to later). This theory is synonymous with the cultural idea of the 'the survival of the fittest'. More recently, Dawkins has revised this theory with respect to the science of genetics, as follows. During the division of cells, e.g. in the production of sperm, the random mutation of a gene can take place when the replication of DNA is imperfect. If it so happens that a particular genetic mutation promotes an organism's ability to flourish in its natural environment, then the gene will survive along with the organism.
In most animals, this is essentially a sperm-centred process of evolution. The integrity of genetic replication during sperm production is often compromised in the course of a male's lifetime, providing many chances to pass on genetic mutations. The female produces relatively few eggs and does so only for a short period of time, providing much less genetic variety through mutation. The female's contribution to evolution is considered possible through sexual selection. The theory is that, through the process of natural selection, sensory faculties have evolved which work in conjunction with the nervous system within the unconscious processing centres of the brain. This enables the animal to further its chances of survival by sensing and, through the unconscious, being compelled to procreate with the fittest mate. Evolution, in this case, is driven by instinct, which is a product of evolution.
There are many problems with this theory, the primary objection being the self-referential or self-fulfilling argument. The interpretation of observations that leads a scientist to formulate a theory cannot entirely be separated from his or her instinct. If, as the theory goes, an animal may be driven to procreate through instinct, then surely a scientist can be driven to formulate a theory through instinct. If humans reside in a civilisation wherein a primary instinct is to be the fittest, this would provide the frame of reference for many of their cultural ideas and scientific theories. There are alternative frames of reference.
Hypothesis
I would like to propose an egg-centred process of evolution, which I will call 'natural design'. The proposed process is not singular; it is composed of a multitude of genetic processes. From the outset I would like to distinguish this theory from both natural selection (1) and intelligent design. Firstly, this is a theory of evolution that attempts to explain how species adapt and develop new functions through genetics. However, it is not related to the notion of selection, whereby the fittest survive and procreate. In this hypothesis, evolution takes place through processes that are subject to the laws of nature (chemistry, physics and biology) - evolution happens by design according to nature. Secondly, I am not attaching intelligence to the design. I am suggesting that nature may have determined particular courses of genetic development, not through intent, but through the activity (or reactivity) of matter, including genetic matter, that is governed by the physical and chemical laws of nature.
Every good hypothesis begins with a good question. Hence, what determines the genetic make-up of the single-cell embryo after the egg has been fertilised by a sperm? In other words, what is the process by which two parents' DNA merge into one? Scientists have found it impossible to predict the outcome of the merging process because of its chaotic nature. From chaos theory we understand that the apparently random outcomes of nature are not, in fact, random. The outcome is indeterminate because of the complexity of nature (which is composed of a multitude of processes) and in particular a highly sensitive dependency on the initial condition (e.g. initial temperature and initial composition). Very small changes in the initial condition lead to far and away, random-appearing outcomes.
Even though the process of DNA merging in the egg is subject to chaos, let us imagine some of the processes involved and the effects of environmental conditions. Firstly, genes are chemical compounds, just like any other chemical or biochemical (natural) compounds. They are subject to the same physical laws of nature as any other compounds involved in chemical reactions. Part of the process of merging the two sets of DNA, therefore, involves the formation of physi-chemical bonds, and therefore gene clusters (complexes) within the product DNA. If the kinetics of this process is sufficiently fast, we can apply the laws of thermodynamics (2). Secondly, any two genes may have originated by evolution in completely different environments (parts of the world or times in history).
What are the thermodynamic rules for the attraction of compounds with significantly different chemical and other potentials? A strong bond may form to enable the two potentials to coexist and provide new function. If a bond between two genes is extremely strong, it may lead to the recession (condensation) of other genes. Thirdly, foreign compounds in the environment may be involved in the chemical reactions. For example, a virus in the egg may become part of the product DNA (could this lead to immunity?). Fourthly, environmental temperature and other factors would directly impact on the products of the gene reactions by Le Chatelier's principle - a Lamarckian notion of evolution. Fifth, and not last, and not least, the emotional and physical condition of the mother when the egg is fertilised would affect the baby's DNA.
Notes
(1) I am not suggesting that evolution is limited to the genetics of natural design. Whereas the first mechanism of evolution may well have been natural selection based on (imperfect) single cell division in the earliest forms of life, the advent of sexual reproduction in animals based on the combination of two sets of parent genes may have heralded a new mechanism of evolution. Furthermore, there are other mechanisms of evolution documented elsewhere, such as genetic drift. Others have speculated that evolution is by no means limited to genetic processes.
(2) It is assumed in the new theory is that the kinetics of gene merging in the egg is sufficiently fast, so as to allow us to apply the laws of thermodynamics. We should also consider the repercussions if the process is kinetically limited in any way.
Mortaza Sahibzada graduated in chemical and bio-process engineering from the University of Bath, carried out doctoral and postdoctoral research at Imperial College London, was a lecturer at the University of Edinburgh, and a postdoctoral research fellow of the Royal Academy of Engineering at Edinburgh and London. He can be contacted by email (mozsahib@yahoo.co.uk).
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