It is hard not to notice that children often look and act like their parents. For centuries, people have been aware, for example, that a man and woman with blue eyes generally produce offspring with blue eyes. Let that same couple produce an heir with brown eyes and rumors swirl.
Only in the last 150 years or so has science dared, or been able, to ask why. One person to thank for that is Hugo de Vries. He was a botanist and one of the first geneticists. In 1889, he postulated that different characters have different hereditary carriers. He specifically postulated that inheritance of specific traits in organisms comes in certain particles….
Botanist to Geneticist to Gene
Born in the Netherlands in 1848, de Vries studied botany at the University of Leiden in the Hague. While there, he discovered Darwin‘s “Origin of a Species” and became curious about variations in species and the role those variations play in evolution. After graduating with a doctorate in plant physiology in 1870, de Vries continued his studies in Germany. His experimental work shifted to heredity and in 1889 he published “Intracellular Pangenisis”, a work that used Darwin’s term “pangene” and defined it as a particle of heredity that produced the individual traits of an organism. Today, we know the term simply as “gene.”
Genes, Heredity and Genetic Mutation Theory
De Vries, as a pioneer geneticist, was widely-known in his time for the introduction of genetic mutation theory. Noticing that individual plants of the evening primrose, Oenothera lamarckiana, growing in his garden were different enough to be a separate species, de Vries began to cross-pollinate them. The resulting variants of the plant he called “mutants.” In his 1901 work, “The Mutation Theory”, de Vries proposed that his mutational jumps better explained evolution than Darwin’s natural selection theory.
De Vries Got it Wrong
There are no fancy monuments to de Vries and, with little mention in literature and no standard biography, he has largely faded into oblivion. Partly, that is because de Vries got it wrong. He thought that the mutations he saw in the evening primrose represented a large genetic mutation rift and thus could explain evolution differently from Darwinian theory. It turns out that is not true. The evening primrose differences that de Vries noticed are now known polymorphisms, a genetic mutation that occurs in more than one percent of a population. Polymorphisms are responsible for normal individual differences like eye and hair color.
The Foundation of Modern Genetics
Although de Vries’ theory was wrong from an evolutionary standpoint, his work, along with others, laid the foundation for modern genetics. He is partially responsible for the term “gene” and the recognition that such a particle determines the characteristics of an individual. His studies also showed that a genetic mutation can be inherited from a parent and that same genetic mutation can be passed to future generations.
Genetic Mutation Theory Today
Today, genetic mutation is defined slightly differently. According to the National Library of Medicine, Genetics Home Reference, genetic mutation is a
“permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.”
Thanks to de Vries, much is now known about the human genome and the specific role of genetic mutation in disease and birth defects. Genetic mutations are now known to be either inherited (hereditary mutations) or acquired (somatic mutations). Both can cause disease or genetic disorders and both are off course of concern to motherhood.
Genetic Mutation and Motherhood
Knowledge is power. Potential mothers need to consider the risk of both inherited and acquired genetic mutation. Testing is available for many inherited diseases. Often a quick blood test can determine if the mother carries a certain gene and its risk of passing to future offspring. Once pregnant, other tests can determine if the fetus is healthy allowing the mother to be proactive in healthcare.
But inherited genetic mutation is not the only concern to mothers. Environmental factors play a role in acquired genetic mutation. For that reason, mothers are cautioned about smoking and drinking during pregnancy as both alcohol and tobacco can cause acquired mutations. Nutrition also plays a role in acquired genetic mutation. New mothers are urged to take folic acid, for instance, to avoid known birth defects.
Recent studies have also shown nutrition in motherhood is even more important than previously thought—and not just during pregnancy. The London School of Hygiene & Tropical Medicine published a study in “Nature Communications” that revealed, for the first time, mother’s diet has a permanent effect on her offspring’s genetics. In the words of Dr. Branwen Hening, Senior Investigator Scientist involved in the study,
“Our results represent the first demonstration in humans that a mother’s nutritional well-being at the time of conception can change how her child’s genes will be interpreted, with a life-long impact.”
Thank you, Hugo de Vries, for starting the marvelous trip into genetic mutation.