It is a scientific fact that the most significant set of genetic instructions human beings receive comes from DNA which has been passed down for generations. However, it has also been scientifically proven that a human being’s environment—especially in youth—can make genetic changes. Researchers have recently learned that these types of genetic changes can have significant impacts 14 generations after they first appear; roundworms were the species that just set the record. The European Molecular Biology Organisation (EMBO) in Spain scrutinized genetically engineered nematode worms that utilize transgene as a fluorescent protein. If activated, the gene causes the worms to glow in UV light.
It was found that the gene glowed faintly at average temperatures and brightly at tropical temperatures, but it was also discovered that the gene continues to glow brightly when it was moved back to normal or cooler temperature. Remarkably, this indicates that the gene retained an “environmental memory” of the tropical climate. Even more shockingly, this memory was passed onto descendants for seven generations. More specifically, it was revealed that baby worms inherit epigenetic change by way of eggs and sperm. According to Adam Klosin of EBMO and Pompeu Fabra University, “We don’t know exactly why this happens, but it might be a form of biological forward-planning.”
Tanya Vavouri of the Joseph Carreras Leukaemia Research Institute in Spain argues that, “Worms are very short-lived, so perhaps they are transmitting memories of past conditions to help their descendants predict what their environment might be like in the future.” Indeed, this is a major reason why these worms were chosen for this particular experiment; 14 generations only took approximately 50 days to evolve. Fortunately, this species and this period of time are more than capable of providing key insights pertaining to environmental genetic change in humans.
However, even though there are significant similarities regarding these changes in worms, mice, and people, human research involving environmental epigenetic inheritance has been hindered by obvious issues: “Inherited effects in humans are difficult to measure due to the long generation times and difficulty with accurate record keeping.” Yet, studies have shown that the children and grandchildren of women survivors of the Dutch famine of 1944-45 suffer from increased glucose intolerance as adults, and other studies have demonstrated that the descendants of Holocaust survivors possess low levels cortisol (cortisol is helpful for recovery after trauma). In particular, recent research regarding nematodes will likely end up being essential to fully understanding our epigenetic inheritance.
The long-lasting nature of these inter-generational effects is fascinating, but it is also somewhat alarming. These findings reveal that human beings may be born with specific genetic traits that were initially triggered hundreds of years ago, and these traits would likely stay with us regardless of the environment we were born in, regardless of the environment we lived in as a child, and regardless of the environment we live the rest our lives in. Hopefully we never find out that much of our freewill was “given” to us by some random family member in the 1800s!
*This content was inspired by an amazing article that can be found here.