Junk & the Epigenetic caterpillar
how new and not so new discoveries in biology are overturning our conventional model of evolution & health
(credit: Wikispaces educational resources)
A new synthesis is dawning…
Professor Denis Noble (eminent physiologist) states:
[…] all the central assumptions of the Modern Synthesis (often also called Neo-Darwinism) have been disproven. Moreover, they have been disproven in ways that raise the tantalising prospect of a totally new synthesis.
And the nature of this tantalizing new synthesis is described by Prof. James A. Shapiro (an expert in bacterial genetics and professor of Biochemistry and Molecular Biology) in the following:
The past […] decades of research in genetics and molecular biology have brought us revolutionary discoveries. Upsetting the oversimplified views of cellular organization and function held at mid-century, the molecular revolution has revealed an unanticipated realm of complexity and interaction more consistent with computer technology than with the mechanical viewpoint which dominated the field when the neo-Darwinian Modern Synthesis was formulated. The conceptual changes in biology are comparable in magnitude to the transition from classical physics to relativistic and quantum physics.
– (Shapiro 1997)
The Boston Review Feb/March 1997 ‘A Third Way’.
It’s all in the Junk
Most of the epigenetic factors involved in our health, inheritance and evolutionary development is found in the so-called junk region of the genome as outlined in the following science article in Medical News Today, under the heading: What is a gene? What are genes? by C. Nordqvist (2013):
Initially, after the Human Genome Project was completed, we thought that much of the instructions for making the proteins that make an organism was contained in a tiny part of the genome, while the rest was simply “junk” DNA, without any useful function.
Later on, geneticists discovered another layer of heritable genetic data that are not held in the genome, but in the “epigenome”. In this area there are instructions on how to interpret the DNA code for the production of proteins. Some of the code for manufacturing the proteins of the epigenome was found to be hiding in junk DNA.
That discovery helped us understand that the c.23,000 genes in the human genome that can be found in all the cells of the human body are expressed differently in different organs and tissues. How they are expressed depends on gene regulation instructions located in the epigenome.
(Source: Press Release from a clinical center for myelodysplastic syndromes relating to a rare blood disorder).
The Epigenetic Caterpillar
The nature of epigenetics means that we now need to re-evaluate our understanding of health as well as our current model of evolution. This is perhaps best illustrated in a clinical article below, as epigenetic processes effect, to what degree, genes are regulated/ expressed (switching on and off of genes and epigenetic inheritance) without actually changing the DNA sequence itself. This principle can be best seen within a well known species and process of development, metamorphosis of a caterpillar to a butterfly. This exemplifies the way in which epigenetic switches can alter the EXPRESSION of genes without changing the genotype (the gene/DNA sequence) which, in turn, can radically alter how an organism looks and its overall characters (phenotype). This therefore, has profound implications for our current gene-centered model of evolution.
Furthermore, this gene regulation/expression is equally applicable to our health and well-being as within even identical twins with identical genomes, their life-style, environmental exposure and stress-levels can have a rather different outcome in the end as epigenetic markers are formed on the epigenome and indeed these can be inherited (See recommended videos at the end of this article). The good news is that nothing is irreversible. In other words, Identical twins = identical genomes: but their epigenomes become increasingly distinct as they go through life.
THE Epigenetic CATERPILLAR AND THE BUTTERFLY:
ONE Genome – TWO Structures
When the caterpillar changes into a butterfly, its genome – its basic genetic sequence – does not change. The differences between its two forms result from turning on and off different genes.
These changes in GENE EXPRESSION (turning a gene on) and GENE SILENCING (turning a gene off), which do not change the underlying DNA sequence, are collectively referred to as EPIGENETICS.
In some cases – the caterpillar and butterfly, for example – these changes are normal and expected and may be required for development.
Epigenetics gives us a deep insight into health and disease and the healing mechanisms already present in the body and therefore, you are not a victim of your genes. .Judging by my research to date, the epigenetic caterpillar and all this entails for understanding how species change through time, will, I believe, profoundly change the way we think of evolution and indeed, our health. When you really think about the way genes can be changed in their expression and how amazing it is that a caterpillar looks and acts so different to a flying insect (a butterfly or moth), yet it has the same genes, does this not tell you something about how species may have changed through time and how we have been looking in the wrong place all this time (the genes) to find the changes brought about in the species, when infact it was environmentally-driven epigenetics all along. Our current model of evolution only allows for a change in genes and their mutations to cause variation: we do not yet, fully grasp that genes can be altered dramatically without even changing the DNA sequence. However, it is unfortunate, (for various historical and ideological reasons which I have gone into elsewhere in my books), that epigenetic systems and their role in evolutionary change and the developmental biology have been fiercely resisted, ridiculed and generally ignored as a viable alternative to our current model of evolution. Otherwise, I feel we would be much, much further on in our biological thinking and how epigenetics and its understanding will, when it is fully recognised, cause nothing less than a paradigm shift (a quantum leap) in our understanding of ourselves, our lives, our planet and all life on it. Nature is so much more clever than any of us could begin to imagine.
Fortunately, things are beginning to change a little and in more recent assessments of Lamarckian principles which are essentially synonymous with Epigenetics are being recognised as valid within our current science as highlighted by Professor Denis Noble’s endorsement of a scientific collection of papers on Lamarck entitled: ‘Transformations of Lamarckism From Subtle Fluids to Molecular Biology’:
This book is long overdue. Lamarck and Lamarckian ideas were not only ignored but actively ridiculed during the second half of the 20th century. As the subtitle of this book indicates, some of the most cogent reasons for reassessing those ideas come from within the citadel of molecular biology itself […]
Bearing in mind that Darwin’s original concept of natural selection allowed for Lamarckian drivers of evolution as seen particularly in Darwin’s later additions of ‘Origins’ and the modern synthesis is quite different to its original form and the fact that earlier ideas of the importance of environmental drivers of evolution (Lamarckian) came to be integrated with saltation ideas of developmental biology or its more modern term: EVO-DEVO (meaning large and rapid changes during development and applied to evolution of the species) will make more sense of the following science paper entitled: ‘Transgenerational Epigenetic Inheritance: Prevalence, Mechanisms, and Implications for the Study of Heredity and Evolution’ by Eva Jablonka and Gal Raz in the Quarterly Review of Biology (2009):
…denied by the “Modern Synthesis” version of evolutionary theory, which states that variations are blind, are genetic (nucleic acid‐based), and that saltational events do not significantly contribute to evolutionary change […]. The epigenetic perspective challenges all these assumptions, and it seems that a new extended theory, informed by developmental studies and epigenetic inheritance, and incorporating Darwinian, Lamarckian, and saltational frameworks, is going to replace the Modern Synthesis version of evolution […]. We believe, therefore, that the impact of epigenetics and epigenetic inheritance on evolutionary theory and the philosophy of biology will be profound.
For more information and historical background on this epigenetic evolutionary principle and its impications for offering a very different interpretation of nature and biological evolution see other publications by this author. An Ebook is available to download on any device for free on usual platforms: Barnes & Noble, i-tunes (Apple) etc or find the direct link on this site.