I have always been fascinated with the concept of time travel. Maybe because I like history or perhaps because of the inevitable paradoxes that can arise with traveling back to the past.
If you killed your parents or grandparents in the past, how could you have been born and traveled back in time? A ball thrown into a wormhole emerges in the past and knock its incoming self away from entering the wormhole in the first place.
As much as I like the concept of time travel, the science that supports it is speculative. Albert Einstein told us that time is relative, and depends on how fast you are moving relative to something else. If you could travel at 99.99% of the speed of light for a year and return to earth, you would have barely aged, while everyone you knew before you left would be dead. For them, you would have been gone for 141 years.
The only wrinkle is that it is impossible to travel at the speed of light. There are theories about creating wormholes between points in space-time, but that only applies to very small particles, not people.
But what if the past actually lives in you? Inside your DNA? A strand of DNA after all is a just a data file. storing information in a base 4 code.
A journey of humans through time
If you have gone through a testing service like 23andMe you have seen first hand how your DNA tells a story about you. Some have called the human genome, which was finally mapped in 2003, a narrative of the journey of our species has made through time.
Your genome, which you can download onto your laptop as a big text file from one of the DNA testing companies, is the book of you - where your ancestors lived and their nationalities, along with a slew of traits you have inherited. Do prefer salty or sweet tastes? Can you smell asparagus? Do you get more or less mosquito bites than others? Other genetic markers can indicate your risks of serious medical conditions, or even whether you are more or less likely to have wet earwax and a pleasant body odour.
Yeah, it gets a little weird reading these reports.
As the study of genetics advance rapidly, research into epigenetic memory has revealed some fascinating possibilities. It seems that the memory of a particularly traumatic event can be passed on from generation to generation. With an epigenetic memory, your DNA sequence is not altered, but rather the expression of a gene (humans have about 20,500 of them) is changed.
As a writer, with a bent towards history and time travel, the possibility of inheriting memories is mind blowing (literally). Assassin’s Creed, the action/fantasy movie and video game franchise of the same name, used a machine called the ‘Animus’ which allowed the protagonist, Cal, to access and re-live the genetic memories of his distant ancestor Aguilar.
But, what if the past actually lives in you? A strand of DNA is just a data file storing a few megabytes of information using a base 4 code.
In my novel series, Song for a Lost Kingdom, Adeena Stuart connects with Katharine Carnegie, a woman born almost 300 years earlier. The time travel is made through their shared composition of musical score. While this is only a flight of fancy from my imagination, if genetic memories are real, could this take it out the realm of pure fantasy?
Crows don’t forget
The evidence for the genetic transmission of memories comes primarily through experiments with animals. I find the most interesting of these comes from observing crows. A comprehensive study from the University of Washington demonstrated that crows remember the faces of people who have harassed them. And researchers believe crows can pass that knowledge on to their offspring.
They don't just pass on a general fear of people, but a grudge against the faces of specific people the crows regard as a threat. While the proof is inconclusive, studies do show crows seem to have the ability to pass information about threats to their safety down to their descendants.
Passing fear down to mouse descendants
Another study, this one involving mice, showed how specific fears can be inherited.
A study at the Emory University School of Medicine found that mice can pass on learned information about traumatic events, such as the smell of the acetophenone. Adult mice were exposed to the scent of this chemical, while getting small electric shocks. The mice eventually associated the scent with pain, even without a shock.
“How the hell is this happening?
This fear was passed down to their offspring, even though they had never encountered the acetophnone. Grandchildren, also had the same fear, as did offspring fertilized in-vitro.
The study was hailed as a groundbreaking demonstration of ‘acquired transgenerational epigenetic effects’. This was followed by the somewhat less elegant statement in one peer review: “How the hell is this happening?”
Starving worms glow in the dark
Researchers at Tel Aviv University wanted to study how it could be that changes in gene expressions, but not the DNA itself, are getting passed on. Basically the ‘how the hell' question, wrapped in the parlance of scientific discovery.
Their experiments with worms showed the process involved passing down small RNAs, the molecule that unpacks the information stored in DNA. A similar study from the Columbia University Medical Centre showed that starvation of roundworms induced changes in their RNA. These changes were inherited through at least three generations.
And finally, a team from Barcelona’s Centre for Genomic Regulation, showed that nematode worms that were exposed to cold and warm environments passed along memories of the warm environment for at least 14 generations. They demonstrated these memories through a glowing gene that fluoresced under UV light.
What about people?
A study that looked at “transgenerational transmission of environmental information” in humans, found that the descendants of WWII Dutch Holocaust survivors had lower levels of the stress hormone cortisol in their blood, making them more vulnerable to stress and fear.
With this same cohort, unique in modern times as they suffered a deliberate starvation at the hands of the Nazis in 1944-45, found their children were smaller than average. The data suggested that the famine experienced by the mothers caused epigenetic changes that were even passed down to the next generation.
Bottom line
We are a long way off from understanding the possibilities of epigenetic memory.
Human memories themselves are elusive - dependent on context and experience. DNA is a blueprint for building a person, but while we carry instincts, and likely some ancient fears implanted from our ancestors, detailed memories are not included, and with our current understanding of the mind, never can be.
However, the transmission of epigenetic memories, that modify the expression of genes has been conclusively documented. Given the ongoing research in this area, primarily in the fight against cancer and other diseases, my guess is we will find genetic switches that pass on detailed and very specific information about our experiences to our descendants.
I would love to write a sci-fi novel using the premise of DNA epigenesis. Some freedom in extrapolations of technology & methodology would have to occur in order to create an easily readable story. The world of hard sci-fi could use a biologically-based time travel odyssey, surely. A sci-fi opera that could be worthy of PF Hamilton!
It makes you wonder how the epigenetic memory transmission might be at work in migrational insects/ animals.
Thanks. "You are what your grandpa eats" - great title. I'll give it a listen!
Great article and very thought provoking. The human epigenetic examples remind me of a study I heard about on Radio lab: https://www.wnycstudios.org/story/251885-you-are-what-your-grandpa-eats/ - the results of that study were somewhat more cheerful. Grandchildren of starved ancestors had better health.