Approximately thirty years ago JD Birchall OBE FRS, Carole Perry and I were asked by Oxford University Press to write the bible on Silicon and Life. Silicon had been the pet subject of Derek Birchall for many years and was the coincidence that brought Derek and I together in 1985 when I began my PhD. Derek knew what there was to be known about silicon’s role in biochemistry but was perplexed by a lack of mechanism. Under his direction my research on aluminium toxicity in fish solved the conundrum and provided the mechanism of silicon’s essentiality. You can read about this research in my previous musing A Contribution to Science.
The bible on Silicon and Life was never written due to Derek’s untimely death in 1995 in a road traffic ‘accident’.
Prior to my research demonstrating that silicon protected against acute aluminium toxicity in fish there was no biochemistry to explain the apparent essentiality of silicon. The latter had been demonstrated by Edith Carlisle in chicks, the classic image taken from her seminal paper is copied below. The chick on the right being deprived of silicon in its diet.
Silicon essentiality was also demonstrated by Klaus Schwarz in rats but neither Carlisle nor Schwarz took any account of aluminium, indeed Carlisle added aluminium to the diet of her chicks mistakenly believing at that time that aluminium was also an essential element.
The difficulty in ascribing essentiality to silicon was and remains the very real fact that there is no recognised silicon biochemistry. To attribute essentiality to an element one must be able to demonstrate that the element forms a chemical bond with the architecture of life. For example, that silicon is found in a protein and that it is bound through some form of direct chemical bond such as Si-O-C or Si-N or any other possible combination. No such bonds have ever been identified for silicon in life and this is why we have to conclude that there is no silicon biochemistry and by conventional nomenclature silicon cannot be described as an essential element of life. Some of the background to this story that would certainly have been covered in detail in the aforementioned and cancelled Silicon Bible can be found in a number of my papers, for example, here, here and here so do feel free to email me to obtain the pdfs of these papers.
But what about Carlisle’s chicks and Schwarz’s rats and the myriad publications and observations that purport to show that silicon is good for Man, beast and plant. The answer is, of course, aluminium poisoning. Carlisle’s chicks and Schwarz’s rats show all the classic signs of aluminium toxicity. The antidote to aluminium poisoning is silicon though more accurately silicic acid, see my previous musing All Heal, Silicic Acid.
To my mind silicon has always been an essential element in life in that from life’s beginning to this day it has acted to keep aluminium out of life. Silicon is THE essential element of life, think about this as you sip your silicon-rich mineral water!
Once again… You are asking sensible questions and then providing sensible answers.
And once again… Thank you for providing ME the key to reversing MY Alzheimer’s! MDs tell me that my cognition has improved from BEGINNING (and supposedly irreversible) Alzheimer’s TO HIGH NORMAL!
It is interesting to learn that the essentiality of silicon to life has been obscured by its “out of the box” location where it was placed by the structured scientific world due to its unrecognized indirect role as a protector of life by preventing aluminum from destroying life. This illustrates a difficulty in discerning cause and effect by limiting one’s view by a reductionist process of elimination which casts out a relevant step in the process. Sometimes it takes more than one cause to construct an effect.