(This article was adapted from our new book Emotional Frustration-the hushed plague.)
After the Darwinian revolutionary writings[i] enshrined the concept that natural selection and evolution were the major mechanisms to modify our bodies, some alternative hypotheses were summarily discarded for the sake of clarity. Jean Baptiste Lamarck, a French naturalist, proposed that all the species have strived to attain the perfect state, for which there are multiple variations; the living organisms not only evolved but they did it slowly, little by little and successively.[ii]
In 1800 Lamarck gave his first lecture in the prestigious Musée National d’ Histoire Naturelle where he discussed the mutability of species—later developed in a book.[iii] According to Lamarck, life becomes diversified due to these factors:
- The Power of Life: tends to make organizations increasingly complex.
- Effects of the Environment: modifying influence of circumstances.
When the molecular structure of the human DNA was discovered by Watson and Crick in 1953[iv], scientists determined that its coded information could not be altered in any significant way by the environment or the person’s lifestyle choices. In 1975 Robin Holliday and John Pugh, English biologists, and Arthur Riggs, an American, found that methylation—an inherited chemical change of the DNA strand—can be modified by the environmental factors.[v] Epigenetics.[vi]
Studying laboratory animals, they discovered that severe environmental stress can have long-term effects in the information provided by the genes, i.e. epigenesis. The genetic material stays untouched but its “expression” or “reading” is greatly altered; this biological alteration can be transmitted in some instances to future generations that have not experienced the initial triggering factor in their lifetimes. Rat or mouse pups are subjected to maternal separation and then their behavior is studied for signs of depression; their genetic material is analyzed for alterations.
Rudolph and Adrian Bird published a seminal paper in 2003 where they said: “stable alterations of this kind are ‘epigenetic’ because they are heritable in the short term but do not involve mutations of the DNA itself. Research over the past few years have focused on two molecular mechanisms that mediate epigenetic phenomena: DNA methylation and histones modifications.”[vii] As part of our reaction to stress, we secrete a hormone called glucocorticoid that mediates certain immune mechanisms like inflammation; when the offending agent disappears, the glucocorticoids bind to some brain receptors and its production in the adrenal cortex stops in a feedback loop. [viii]In 2106 Gustavo Turecki and Michael Meaney published a paper where they show that the gene that codifies this glucocorticoid receptor is inactive in animals that had experienced great stress in their early days, thereby limiting their ability to shut off its production.[ix] Even after the cause for stress has disappeared, they keep producing the stress hormone.
The epigenetic mechanism consists of a physical barrier of methyl markers in the DNA, which prevents the proper reading of the stored information in genes. Can this epigenetic trait be transmitted from a mother to her children? Scientists are still debating this issue but there are indications that when the DNA replicates during the cell mitosis, the methyl markings can be introduced in the new genetic material.
Scientific studies have shown that when women are subjected to undue stress during pregnancy, they give birth to children with impaired responses to stress. After the Allied landing in Normandy in August 1944, there was a prolonged stand-off between the opposing armies in the Lower countries, Belgium and Holland.[x] In order to force the population into not helping the Resistance and the advancing armies of Montgomery and Patton, the German Army rationed food supplies.[xi] The women who were pregnant at the time of the tragic Dutch Hunger winter, eventually gave birth to children with a higher rate of obesity and schizophrenia. Nadine Burke Harris says that the origin of many of our societal problems may arise from the exposure to undue stress in childhood that leave a genetic marking.[xii]
Did our mothers and grandmothers possess the right intuition before science confirmed it?
What do you think? Please tell us.
Don’t leave me alone.
[i] Charles Darwin, “On the origin of species”, Mass Market Paperback, New York, 2003.
[ii] Encyclopedia Britannica, “Jean-Baptiste Lamarck”, https://www.britannica.com/biography/Jean-Baptiste-Lamarck
[iii] Jean Baptiste de Monet de Lamarck, « Recherche sur l’organisation des corps vivants : précédé du discours d’ouverture du cours de zoologie donne dans le Musée d’Histoire Naturelle » Fayard, Paris, 1986.
[iv] Leslie A. Pray, “Discovery of DNA structure and function: Watson and Crick” Nature Education, 1(1):100, 2008.
[v] Nelson Cabej, “Building the most complex structure on Earth: an epigenetic narrative of Development and Evolution of animals”, Elsevier, February 2013.
[vi] Israel Rosenfield, Edward Ziff. “Epigenetics: The Evolution Revolution”, The New York Review of Books, June 7, 2018. https://www.nybooks.com/articles/2018/06/07/epigenetics-the-evolution-revolution/
[vii] Jaenisch R., Bird A., “Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals” Natural Genetics, 2003 March, Supplement 245-54.1
[viii] Robert M. Sapolsky, L. Michael Romero, Allan U. Munck, “How do Glucocorticoids Influence Stress responses? Integrating Permissive, Suppressive, Stimulatory, and Preparative Actions” Endocrine Reviews, Volume 21, Issue 1, February 2000, pages 55-89. https://doi.org/10.1210/edrv.21.1.0389
[x] William Shirer, “The rise and fall of the Third Reich, Fiftieth Anniversary edition”, Barnes and Noble, 2018.
[xi] Ibidem as above.
[xii] Nadine Burke Harris, “The deepest well: healing the long-term effects of childhood adversity” January 2018.