Epigenetics – The Return of Lamarck

203 years ago a scientific theory was released that took the evolutionary world by storm. Darwin was less than a year old when Jean-Baptiste Lamarck released his book Philosophie Zoologique in 1809. Data collected from his time as Professor at the Natural History Museum in Paris had thrown up a revolutionary new idea in the scientific world – inheritance and evolution were truly born. Later, Darwin started his confused life literally probing and testing evolutionary theory. Since its publication on 24th November 1859, The Origin of Species has been at the forefront of scientific research, helping explain the complexities seen in the natural world. Now the world of epigenetics is turning the tables, taking Lamarck and placing his ideas back in the limelight.

The epigenome is a relatively new field of research. An epigenome is a small chemical compound that sits atop of genes. Methyl marks add themselves to the DNA bases and proteins called histones wrap around the protein bases. Combinations of molecules can attach to so-called “tails” on the histones and affect the DNA that the histone is wrapped around. These two types of epigenomes are both environmental. They are not affected by inherited chromosomes; instead they are changed and developed during a person’s lifetime. The best example of this is a study by Dr. Lars Olov Bygren in the 1980s. He took a random sample of 99 people from a remote Swedish village of Overkalix and used historical records to track their parents and grandparents, and then cross referenced this with how much food had been available to each generation. They went back from the 1980s to 1905. Their results conclusively showed that parents who were gluttonous and had ample food had children whose life spans were shorter by roughly 6 years.

As such we arrive at an issue. Epigenetics suggests environmental changes affect inherited genes, and thus the age old debate can be rekindled with a new twist; are we in charge of our own decisions? Centuries ago we were told by religious priests, rabbis, imams and vicars that gods are in charge of our fate. Lamarckian theory that what we eat or what we do may affect our genetics also suggests that we are not in control of our fate; science has brought back the idea of predetermination. If the theory is correct then predetermination has already decided important events in our lives such as our intelligence, physical capabilities and when we eventually die – possibly even by what cause.

Predetermination itself raises a moral issue in our secular society. The fact that someone can blame their genes for any action that they take means that they can claim to not be responsible. Ethically this is not morally acceptable for the rest of society to take the burden and to have to let people off without charge. As such this cannot be allowed to happen.

However what is more important is the scientific problem that arises as a result of epigenetics. Our secular society is built upon a set of moral and scientific principles that are in themselves absolute and cannot be broken under any circumstances. Epigenetics brings Lamarckism back into question. Darwinism and Lamarckism are opposite sides to the evolutionary argument. Current scientific principles are such that only one theory can be correct, however clear evidence for both Lamarckism and Darwinism exists. Neither can be disproven without using the other as an explanation; and with the rise of epigenetics the evidence is as strong for both sides. Darwin’s greatest theory is often downplayed in science lessons, and Lamarck is mentioned only as the theory that Darwin disproved.

183 years after his death Lamarck is yet again causing an upset, but against science this time not religion. Although not with us today, Lamarck is still wise beyond the grave. In arguably man’s greatest time: “the great age of the earth will appear greater to man when he understands the origin of living organisms” – from ‘Hydrogéologie’ by Lamarck (1802). We all know where we stand scientifically and ethically in the natural world. Hopefully one day we will understand how we got here, the true science of evolution.

Contributed by Andrew Wood

One thought on “Epigenetics – The Return of Lamarck

  1. “Current scientific principles are such that only one theory can be correct”

    Can be untrue as you can both have normal Neodarwinian mutation and natural selection as well as epigenetic effects working at the same time. There is no reason one should exclude the other. The question is how big of a role epigenetics play.

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