Since the 19th century, the era of Mendel and Darwin to the fast developing generation in 20th century, scientists had very limited knowledge about the chromosomes nature and behavior. According to them the genetic design of development takes form when a pair of chromosomes passes from parent to child. But later, these assumptions and theories took a drastic change. A scientific revolution started, where researchers discovered a new trait of genes. They realized that gene is much different from a simple predetermined program passing from parent to children. In fact, the quality of experiences and environment influence the nature of genes.
Things like the eating habits, quantity of undergoing stress and exposure to type of toxin can bring changes to the genetic legacy. The emerging science of epigenetics has added new definition to gene theory.
Researchers are putting their diligent effort to find out the combination of nature and nurture leads to considerable changes in behavior, illness and traits. Genes alone are not responsible for various conditions that may range from autism to cancer to sexual orientation. Molecular biologist from Rockefeller University, C.David says, “We were all brought up to think the genome was it. It’s really been a watershed in understanding that there is something beyond the genome.”
What it Epigenetics?
The word Epigenetics stands for “on top of genetics.” Epigenetics is the study of human genes and how they get influenced by life experiences. It further explains how genes can be turned off and on. Each cell of the body along with neuron and skin cells has a unique DNA blueprint, yet they are witnessed performing a variety of different functions. The main reason behind it is that epigenetic “tags” blocks the development of fetal cells and prevents it from following genetic instructions that are useless to intended roles or operations. Scientists discovered that biochemical process takes place during early development, gestation and even throughout adulthood. The impact on genes also alters the physical and mental health of the individual.
How Can Epigenetics Affect Your Personality?
As an example, stress can impact fetal epigenetic tags. On examining expectant women who were suffering from the trauma of 9/11 World Trade Center incident, they were found more likely to epigenetic alteration, in comparison to other women. Infants of the traumatic women were diagnosed with high levels of stress and fear while interacting with unfamiliar people, new foods or loud noises.
Diet is thought to be a factor in determining your future personality. Most prenatal diets are low in vitamin B-12, folic acid, and various other nutrients including “methyl groups” (group of molecules), which can cause epigenetic changes by tagging genes. These diets open heightens the risk of spinal and brain defects and asthma in children. Furthermore, it is believed that certain peptides in our foods, such as the peptide lunasin which is found in soy and some grains may turn on and off the switches hinted at by epigenetics.
Can Changes Stay Hidden and Take Place Later in Life?
Yes! Absolutely. In most of the abuse cases, young children show more clear possibility of epigenetic changes, which reduces their ability to cope with stress. While in some cases where twins are born, the gene predisposes both the infants to cancer, however only one of them develops the disease. The reason behind the alteration are toxins, diet, or smoking that turns on the gene in one, while the other lives a cancer free life due to different habits. Alice G. Walton, a health journalist, believes that human personality do not solely depends on genes. She believes that in some or many ways, genes can get influenced by the habits, lifestyle and health decisions of an individual.
Are Changes Hereditary?
According to the theory of Darwinists, there is a possibility that change is hereditary. Researchers thought that on combination of an egg and sperm, all the epigenetic tags gets erased, thus leaving the embryo like a clean slate. But, later it was found that nearly 1% of the epigenetic tags successfully escape the erasure. They pass to the offspring directly and potentially in future generation of the offspring. Soon, many evidences supporting this theory became evident. For example, women of Netherlands, who conceived during the 1944–45 desperate wartime famine, gave birth to smaller-than-usual babies. That shows that impact of their diet, toxins intake and traumas/stress they were exposed to, which affected their children and could influence the health of grandchildren as well. Zoologist David Crews from University of Texas did multigenerational studies and experiment with rats, which explained that obesity, soaring and autism could be something that transferred from grandparents, who were exposed to “1940s chemical revolution.” The exposure also includes the introduction of fertilizers, new plastics, detergents and pesticides.
Are There Any Medical Therapies Available?
A biologist of Whitehead Institute in Cambridge, Robert A. Weinberg, says that the evidences collected for over past five years, explains that epigenetics is the key cause behind cancer. While director of Johns Hopkins University’s Epigenetics Center, Mass. Andrew Feinberg, believes it to be an active factor in diabetes and autism as well.
Drugs are being introducing intending to undo the cancerous epigenetic alterations. Moreover, eating foods featuring rich gene-altering methyl groups (like soybeans, green tea and red grapes) may defend you from diseases by blocking the detrimental genes. In a research, a pregnant female mouse was fed methyl-rich diet, which carried a gene. The gene made them prone to diabetes and cancer along with making them grow fat and yellow. Even though, after carrying the same gene, their offspring were born disease-free, slim and brown. Researchers are putting all their effort to find out an effective way to employ this powerful tool in serving humanity by addressing specific health problems. Moshe Szyf, a McGill University pharmacologist asks, “Did the diet alteration helped reduce the cancer risk? Did it elevate the level of depression? Did it lead to increase in Alzheimer or dementia?” These questions are not clear yet and it will take time to become evident.
Lamarck vs. Darwin
Darwin proposed his theory and the natural selection principles in “On the Origin of Species”. But before him, Jean-Baptiste Lamarck, a French naturalist of 18th-century, gave a different theory on evolution. According to him, organisms have the ability to pass on traits that they’d acquired in their life. Lamarckism, further supported the theory using a (false) idea that giraffe posses long neck because it constantly stretches it out to reach higher branches for leaves. Later, at the beginning of 20th century, another researcher, August Weismann questioned the theory. He chopped off the mice tails in support of his idea that born pups do not inherit this loss. Renato Paro, a Swiss bioengineer suggests that though the theories of “Darwin were 100% right” about evolution, epigenetics denies some of it major ideas. “Passing on the gained traits,” he added, “fits more aptly to Lamarck’s evolution theory.”
It is believed that certain peptides in our foods, such as lunasin which is found in soy and some grains may turn on and off the switches hinted at by epigenetics.
Epigenetics: Are Our Genetics Hardwired?
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