Do the Experiences of the Ancestors Leave Epigenetic Markers on your Genes?
From the early days of Systemic Family Constellations, facilitators have asked their clients, “What if the pain you’re carrying is not your own?”
The Constellations community accepts Hellinger’s axiom that an individual can become entangled with the fate of an ancestor. A child does this out of love—bringing happiness, or more often despair!
Bert Hellinger suggests that very early in life, the child makes a decision—consciously or unconsciously—to carry the fate of an ancestor. The science of epigenetics shows that the “fate” of an ancestor is epigenetically heritable—a biological process!
Research in epigenetics shows that trauma, experiences, and behaviors of the ancestors can be inherited by their offspring for as many as four generations, and perhaps even longer, by changing the expression of various genes. These epigenetic changes are stored in the epigenome and can be transmitted transgenerationally to subsequent generations.
Historically scientists believed that an individual’s destiny was determined by his or her genes—hence the term “DNA is Destiny!” Epigenetics is a sub-discipline of biology that studies changes in genomic expression that do not involve changes in the underlying DNA. The word epigenetics comes from the Greek epi and genetics because epigenetic changes occur outside or above the genome, and it is above the DNA sequence that the Epigenome rests. Permanent epigenetic changes are stored in the epigenome and can be passed to subsequent generations.
Until recently students were taught only that a new embryo is created by the joining of the mother’s ovum and a sperm from the male with 50% of the new embryo coming from the mother and 50% from the father. It was understood that each individual has unique DNA that remains fixed for life, with the exception of monozygotic or identical twins, who share the same DNA.
Genes and how they Work
Genes are the instruction book for the human body and although every cell contains the same DNA, each gene receives specific instructions in the form of chemical markers, or switches, that lie along the length of the double helix and forms the epigenome. Every cell in the body contains the same DNA, containing the master code within each cell—the instructions for the creation of a human. The master code directs the developing organism which genes to express and when. This binary process controls a series of switches that are turned ON or OFF, directing each cell to become—a heart, a tooth, skin cells, or a brain, etc.
In the traditional view in biology, it was believed that the DNA of each individual remains fixed throughout for life. Whereas DNA does remain fixed for the life, DNA no longer tells the whole story—epigenetics changed everything!
The epigenome is flexible and adjusts the expression of specific genes required to create various parts of the body—in responsible to environmental factors that influence the expression of the genome. The position of each switch instructs the genes—with the ON or OFF switches instructing the gene to express or not to express. This is the method by which development takes place—thereby creating various organs and ultimately a unique individual is created—except monozygotic
The Human Genome Project (HGP)
The Human Genome Project (HGP) identified approximately 24,000 genes—the instructions for creating a human body. Scientists expected to find humans have around 100,000 genes, and were shocked to discover that each individual has only 24,000 genes—just a few more than a chimpanzee or even a rat!
Epigenetics is a sub-discipline of biology that studies the heritable changes in genome expression that do not involve changes in the underlying DNA sequence. The name comes from the Greek epi, meaning over, or above, the genome.
Epigenetic changes occur as the result of interaction with the environment, the changes the expression of the genome. The expression of the genes can change, while the underlying DNA remains the same. Epigenetic changes take place outside, or above the code contained in the DNA, and then are stored in the epigenome. In the early days of epigenetic research, it was believed that epigenetic changes could only take place in the developing organism prior to birth. However, as research progressed, it became apparent that epigenetic changes can occur throughout the lifetime of an individual.
Research shows that traumas, certain experiences, and many behaviors can result in changes in the expression of certain genes, and that these epigenetic changes are stored in the epigenome, and these stored epigenetic changes can be transmitted transgenerationally. However, not all epigenetic changes are permanent, therefore are not heritable.
Sometimes these epigenetic changes produce unwanted or unpleasant results, but as investigation in epigenetics continues, it becomes increasingly more apparent that epigenetic changes are often very positive. And, since epigenetic changes are reversible, by changing the environment to a more positive one—by eating different foods, listening to soothing music, exercising, meditating, or enjoying other positive activities—negative, or unwanted epigenetic changes can be reversed. Positive epigenetic changes occur when an individual leads a positive lifestyle, and these positive epigenetic changes can be passed to future generations.
Epigenetics vs Lamarckism
Lamarck suggested the theory of the inheritance of acquired characteristics, known as Larmarckism. He claimed that giraffes stretched their necks to eat off the top of trees, so it became an inherited quality. Many scientists believe that epigenetics also suggests that acquired characteristics are heritable.
Epigenetics and Identical Twins
The link below is to a short video describing how environmental factors create epigenetic changes in genome expression. These epigenetic changes often result in identical twins maturing very differently from each another.
Identical twins develop from a single fertilized egg, and as a result have the same genome or DNA. Differences between identical twins are due to environmental experiences, not genetics. These environmentally-caused differences are stored in the epigenome.
As is often the case in science, studying identical twins provides insights into otherwise unknowable issues. Researchers compare various characteristics in identical twins in an effort to determine which traits are inherited and which develop in response to environmental influences. Particular attention has been paid to the development of certain traits, especially complex behaviors and certain diseases. The environment is studied to determine what factors may have influenced one twin and not the other.
About 50% of identical twins both develop schizophrenia, whereas only 10-15% of fraternal twins do—suggesting a strong genetic component. However, if the development of this extreme disorder were only genetic the concordance would be 100%, so the environment is a very large contributing factor.
Peak Experiences or Traumas
People often comment that they are forever changed as the result of a particular event or experience. A traumatic event such as 9/11, wars or forced migrations from the homeland, such as that which is happening today in the Middle East and parts of Africa, tends to result in epigenetic changes with unwanted results, including mental and/or physical stress, disease or other disorders. The good news is that negative effects can be reversed by making positive changes in diet, exercise, and by adding meditation, positive thinking and other changes in surroundings through the use of colors, textures, lighting, music, and so on.
On the other hand, positive experiences, sometimes known as peak experiences, can result in the growth of new neuronal pathways in the brain. This enhances the brain’s ability to learn and to experience life more fully and in a more positive way.
With no more than a change in diet, laboratory Agouti mice (left) gave birth to young (right) that differed markedly in appearance and susceptibility to diseases.
One of the earliest researchers in epigenetics, Dr Randy Jirtle, Professor of Radiation Oncology at Duke University, was interested in discovering if the Agouti gene—responsible, responsible for producing laboratory mice with ravenous appetites, and prone to obesity, diabetes and cancer, could be silenced. Jirtle and a group of his post-doctoral students at Duke University took pairs of fat yellow lab mice that carried the Agouti gene. Beginning with conception, the mother mice were given methyl-rich diets.
Methyl factors are small chemical markers that act as switches, turning genes ON or OFF, silencing the expression of the Agouti gene. Methyl-rich diets are found in common foods, including onions, garlic, beets, and food supplements rich in folic acid. Folic acid is often given to pregnant women, or women who are planning to get pregnant. Agouti mice generally produce offspring that are identical to the parent mice—fat, obese mice that are susceptible to numerous life-shortening diseases, including diabetes and cancer. However, the addition of the methyl-rich diet fed to these mice, produced offspring that were slim, brown, and virtually immune to the life-shortening diseases that resulted in a radically shortened lives of the parent mice.
Dutch Hunger Winter
One of the most studied periods in history is the Dutch Hunger winter of 1944-1945. A rail strike, a Nazi food embargo, and the coldest winter in history resulted in an extreme food shortage in the still German-occupied territories of Holland’s northwest. By November 1944, rations plummeted to 1000 calories a day per person, and by spring food supplies allowed only 500 calories a day. Over 20,000 people died and those who lived suffered terribly.
The Dutch are impeccable record keepers, leaving an already established cohort for future researchers with an abundance of historical data. Research using data from the Hunger Winter and the health histories of individuals who were still in utero in various phases of development during the famine, shows show that prenatal famine is associated with various unpleasant or sometimes life-threatening consequences later in life, including increased risks for heart disease and higher incidences of schizophrenia. A greater prevalence of schizophrenia was also found in the offspring of women who were pregnant during the Chinese famine of the Great Leap Forward in 1959-1960.
In the mid-1930s, Hans Selye, MD, PhD, of McGill University in Montreal, Canada was a pioneer and one of the earliest researchers to isolate the existence of the stress response. It was Selye who coined the term stress, long before other physicians considered stress to be an important factor in diagnosing disease in their patient. According to Selye, stress can be anything from prolonged food deprivation, swallowing a foreign substance, a good workout, or a great evening out. Selye suggested stress could be positive or negative, and still impact the individual. Although he was unable to isolate the numerous functions of glucocorticoids, Selye was the first to consider the importance of the environment in the apparent genetic variations he observed. He isolated individual stress responses and also noticed that some responses to stress are culturally-specific—entire communities often respond to a traumatic event in similar ways.
Fifty years later, also at McGill University, Drs Moshe Szyf and Michael Meaney first discovered postnatal inheritance and introduced the new discipline of behavioral epigenetics. They discovered the environment continues to influence genomic expression throughout the lifetime by exploring the influence of behavior of rat pups and their mothers, and that positive life experiences can change the expression of the genes as significantly as trauma can. Rat pups with high-nurturing mothers were better able to handle environmental stressors later in life. Pups with non-nurturing mothers experienced epigenetic changes that resulted in pups that struggled with stressful situations, they startled easily, exhibited high stress behaviors—they grew up to be nervous wrecks!
In later research with human subjects Szyf and Meaney found that timing is an important factor. If a child’s parents experience a major life change like winning the lottery, the effect on genomic expression is greater on a child who is around two years old, than it would be if the child had grown to adulthood when the parents had the same windfall.
With advances in epigenetic research it was found that the separation of an infant from its biological parent, in particular the mother, causes extreme stress that is accompanied by significant unwanted epigenetic changes that can persist for a lifetime, resulting in increased vulnerability to disorders of mental and/or physical health. The stress is generally so severe that parenting adopted children requires significantly more nurturing to reverse these unwanted epigenetic effects. Although such early stress is not a simple fix, it is possible for individuals who did lose their biological parents at birth can by implementing the positive lifestyle changing mentioned earlier can have a definitively positive effect as well.
Epigenetic Responses to Trauma
Today scientists emphasize the biological basis for trauma, and suggest that humans share innate responses to perceived threats that are common amongst animals and birds—fight or flight. Trauma specialists Drs. Peter Levine, and Anngwyn St Just, suggest there is a third response to threat—to freeze. Animals and birds easily shake off this frozen state, but humans appear to have forgotten how to re-set, resulting in the frozen trauma being stored in the body. Frozen trauma results in epigenetic changes that can continue to impact the individual for his or her entire life, and can also be passed to offspring for several generations.
Dr. Rachel Yehuda, Professor of Psychiatry and Neuroscience at Mount Sinai Hospital in New York City. She is a recognized leader in the field of traumatic stress and Posttraumatic Stress Disorder (PTSD). Her research on cortisol and brain functions has revolutionized the understanding and treatment of PTSD, including the transgenerational transmission of both. In her research with Holocaust survivors, Yehuda discovered that children and grandchildren of Holocaust survivors are impacted as much as their parents, as a result of epigenetic inheritance of the traumas experienced by their parents.
This is made possible because heritable epigenetic markers are stored in the epigenome, creating a biological memory of the experiences suffered by their parents who survived the horrors of the Holocaust. These inherited epigenetic changes as the result of their parents’ traumas, result in increased susceptibility to PTSD, depression, and other mental disorders in the offspring of survivors. Historically it was assumed that this increased vulnerability to stressors, found in the children of Holocaust survivors, was due to environmental factors such as poor child-rearing practices of traumatized parents. Whereas there could be some truth to the idea that parents who experienced extreme traumas, today science can demonstrate that much of their increased vulnerability to trauma is inherited biologically.
In addition, children of Holocaust survivors often have nightmares in which they are being chased, persecuted, or tortured—they’re convinced that they’re going to be annihilated. These offspring of survivors of extreme traumas are reliving the horrific experiences of their parents or grandparents from WWII, experiences that were passed epigenetically across generations. Offspring of Holocaust survivors have inherited the unresolved unconscious minds of their parents or grandparents.
Epigenetic Inheritance of the Effects of War
Since WWII, it has become increasingly more apparent that veterans tend to exhibit increased vulnerability to PTSD and other mental disorders. Not much has been written about the effects of war on returning soldiers from WWII, except the occasional reference to a phenomenon known as shell shock. WWII veterans were encouraged to remain quiet about their experiences from the war, and although many were able to tough it out, unfortunately not all veterans could. However, by the time veterans of the Vietnam War and the Gulf War, it was an acknowledged fact that many suffered from PTSD, resulting in epigenetic changes that were transmitted to their children and grandchildren, resulting in significantly altered vulnerability to PTSD and other pathologies.
World Trade Center Disaster
Survivors of the collapsed or damaged buildings as a result of the attacks on the World Trade Center on September 11, 2001, were among those exposed to the majority of the reported injuries, air pollution, and traumatic events. Health outcomes were evaluated from interviews conducted from September 5, 2003, through November 20, 2004, by the World Trade Center Health Registry. It was intended that the Health Registry would continue to monitor the mental and physical health of the more than 70,000 individuals who were impacted by the disaster and enrolled in the Registry for a minimum of 20 years. However, recent reports indicate that funding is about to expire after years, or 2016. The enrolled subjects were limited to adult survivors of the collapsed buildings, excluding those who were involved in rescue and recovery operations.
More than half of the survivors of the collapsed buildings were caught in dust and debris clouds resulting from the collapse of the twin towers, while the majority experienced traumatizing psychological events. Physical Injuries were also common, but few reported injuries requiring extensive medical treatment. However, many experienced serious respiratory problems, serious heartburn and/or acid reflex, or severe headaches. These serious effects resulted in major epigenetic changes that are likely to be transmitted to subsequent generations.
The theory of Historical Trauma was developed by Dr. Maria Yellow Horse Brave Heart. According to Brave Heart, Historical Trauma is the result of the cumulative, emotional and psychological wounds that appear as depression, substance abuse, diabetes, dysfunctional parenting, and unemployment amongst Native American people. These disorders, Brave Heart maintains, are the result of the traumatic experiences of their ancestors perpetrated by the dominant European culture for more than 500 years.
Unfortunately, despite the comprehensive body of research on the transgenerational effects of the Holocaust, many so-called experts in the mental health field continue to challenge the validity of the claims that the horrors experienced by Native American ancestors continues to be passed transgenerationally to the people today, resulting in serious medical, psychological, and cultural difficulties.
Post Traumatic Slave Syndrome (PTSS)
Dr. Joy DeGruy coined the name and description of the phenomenon that is known Post Traumatic Slave Syndrome (PTSS). PTSS is a set of behaviors and beliefs associated with, or related to, the multi-generational trauma experienced by many African Americans—in particular descendants of slaves. DeGruy suggests that PTSS is similar to PTSD, but she believes the treatment for PTSS is very different.
However, although DeGruy claims that PTSS is not a true psychiatric disorder that can be treated clinically, and insists that rather than being the result of epigenetic changes, PTSS persists because parents continue to teach children the same behaviors they learned. DeGruy’s ideas are very similar to social scientists who view the disease process as a function of society, rather than a biologic phenomenon.
Research is needed to explore the epigenetic effects of slavery for generations here in the US, the Caribbean, and South America. Additional epigenetic research could potentially trace epigenetic changes back for generations—all the way to Africa—where slaves were captured and sold by other Black Africans, possibly resulting in the black on black violence seen in many major US cities today.
Epigenetics of Same-Sex Orientation
Research to investigate the cause or causes of same sex orientation has produced a variety of explanations, including: genetics epigenetics, hormones, in utero stress or stressors, as well as early environment and developmental experiences. Findings indicate that same-sex orientation tends to run in families, but to date, no single gene appears to be responsible. However, same-sex orientation tends to run in families, suggesting a genetic or heritable component. There is a higher incidence of lesbianism in families than the incidence of gays, leading researchers to consider the likelihood that different mechanisms must be different in females than in males. Although it is very clear that same-sex orientation runs in families, only 20% of monozygotic twins are both gay or lesbian
The Androgen Cycle
Research shows that sexual dimorphisms of the genitalia and brains of humans are strongly influenced by exposure to androgens in utero. Sexual dimorphism is a variation in phenotype between males and females in organisms that reproduce sexually—the main differentiation being in the appearance and function of the reproductive organisms. Other differences can be body size, strength, behaviors and other characteristics or traits. In studies with laboratory rats, XY fetuses exposed to androgen antagonists during gestation develop feminized genitalia, brains, and behaviors, whereas XX fetuses exposed to elevated androgens developed masculinized phenotypes.
The classical view is that higher androgen levels in XY fetuses masculinize sexually dimorphic traits, while lower androgen levels, together with higher estrogen levels, can feminize trait development in males. In the period immediately following conception, both male (XY) and female (XX) fetuses are fairly identical. Androgens act on fetuses of both sexes, facilitating the development of sex-specific organs. But when the XX fetus gets too much androgen, congental adrenal hyperplasia (CAH) can occur, resulting in physical genital confusion. A female can develop male genitalia, and a higher incidence of same-sex attraction. Somewhat later in development, the XX fetus generally develops a uterus and ovaries, but not always.
Although most male fetuses have higher levels of testosterone than females, there can be a significant overlap—resulting in some XX fetuses having higher testosterone levels usually found in XY fetuses. The transient overlap of an unambiguous fetal gender could be genuine, but could possibly something that requires further study and may possibly be a factor in same-sex orientation.
Historically, so-called females with ambiguous sex organs were referred to as hermaphrodites. When gender-confused organs were visible at birth, doctors in the United States arbitrarily decided that the infant was to be raised female—and the underdeveloped male genitalia were removed, and the child was raised as a girl. Unfortunately, many infants with ambiguous genitalia are male, and their gender identification remains in confusion throughout their lifetime.
In addition to the effects of the androgen cycle on the development of ambiguous genitalia, and on same-sex orientation in some females, there is a strong suspicion—as yet unproven—that transgender identity may also be the result of the androgen cycle. The visible sex organs of the transgender individual are generally fully developed and gender-specific, but the internal experience of the individual is the sense that he or she was born the wrong gender. Unfortunately, there is no test that can accurately determine a child’s true gender—even when a child insists he or she is not the gender assigned to him or her at birth. This is true even when the child’s genitalia are visible and fully developed at birth. However, most transgender individuals report that they knew they were the opposite gender at a very early age
The commonly held view that there are only two genders and that gender and anatomy are synonymous, has resulted in a lack of acceptance of transgender individuals in many Western cultures, but this narrow viewpoint is no longer considered to be correct. However, in Native American cultures and with First Nations Peoples of Canada, Two-Spirit Peoples are widely accepted, and many tribes identify four different genders.
Same-Sex Orientation and Child Sexual Abuse
Research suggests same-sex orientation is likely the result of a combination of genetic, hormonal, environmental, and social factors that begin in utero and continue throughout childhood. However, there is a strong association between early childhood sexual or physical abuse, inter-parental violence, and same-sex orientation in adulthood. After decades of research, it remains challenging to disentangle the causal relationship between child abuse and sexual orientation in adulthood—even if the biological, or genetic, factors could be isolated.
Although it is not widely accepted, some researchers maintain that early childhood mistreatment causes same-sex orientation in adulthood. Other research found that gender non-conforming behavior in children increases the likelihood of sexual and/or physical abuse, or mistreatment. Although no causal relationship has been established, research shows that children who experienced early childhood sexual abuse have an increase in the prevalence of same-sex orientation in adulthood.
Swedish Grandfathers’ Food Supply
The transgenerational effect of nutrition on pregnant women was obvious in the data collected during the Dutch Hunger Winter. However, the effects of exposure to feast or famine had not been looked at until Lars Bygren, of Sweden’s Karolinska Institute decided take his research to his birthplace of Överkalix in the far north of Sweden. The Swedes are meticulous record-keepers, much like their Dutch neighbors. They record data on births, deaths, family lineages, as well as the details of the harvests dating back hundreds of years. Because Överkalix was so isolated, it formed another natural cohort—much like the cohort of the Dutch Hunger Winter.
Överkalix is a group of tiny villages in the northernmost county of Sweden, with a population of approximately 3,700. Inhabitants descend from the early settlers who migrated to Överkalix in the 15th century. Bygren was born in Överkalix, a descendant of his many-times great-great-grandfather, who settled there in 1475. Överkalix residents keep livestock and catch fish in the summers, but for the most part, they depend upon the harvest for survival during the six-month long Swedish winter. A failed harvest results in a winter without sustenance, while residents indulged in gross overeating following an abundant harvest.
Bygren chose 100 males, born in Överkalix in 1905, and their grandsons, born many years later. He explored years of feast or famine, but excluded year of normal harvest. He wished only to explore the effects of too much or too little food during the grandfather’s “slow growth period” (SGP)—the period immediately preceding puberty, when sperm cells are formed. The results were a great surprise.
Males whose grandfathers experienced abundance during their SGP, died approximately six years earlier than those whose grandfathers were exposed to famine during the same period. Diabetes was the highest cause of death of the cohort whose grandfathers experienced abundance. However, when controlled for socioeconomic status (SES), the life expectancy was 32 years lower for those in the lower SES group, for grandsons whose grandfathers experienced “feast” years during their SGP. Abundance of food for grandfathers, resulted in grandsons’ statistically significant earlier deaths—32 years in lower SES.
Nature vs Nurture
Nature vs nurture has been argued by philosophers and psychologists for hundreds of years—that changes the zeitgeist of the times. These great thinkers disagree on how behaviors develop and are passed to future generations. But epigenetics dispels the argument and shows that everything that is passed across generations is the result of epigenetic changes from genetics and the environment.