Tiny tots these days are fascinated by gadgets and if you ever observe young infants handling your phone, they seem to have an intuitive sense of how to operate them. Could it possibly be that what parents have learnt through their life can be passed down to further generations? If you don’t believe it’s possible, then how can you explain evolution? However, for a long time, there was only indirect support for the idea, but newer research has found that some types of knowledge can be transferred genetically.
In a study conducted by a team of researchers at Emory University School of Medicine and published in the journal Nature Neuroscience, they tried to transfer a fear memory from one generation to the next.
Experiment: Cross-species fear memory transfer
They first conditioned mice to fear the smell of a chemical Acetophenone by repeatedly pairing it with electric foot shocks. Acetophenone has a citrus orange-like smell. The reason the researchers used this particular chemical was that the receptors for this chemical in the sperm are the same as those in the nose. The mice learnt to fear the smell and avoid it. Then, sperm from the mice was artificially inseminated from father to pup. When the pups were tested later by exposing them to different smells and observing their startle response, pups with traumatized/fear-learned dads showed a greater response to the smell of acetophenone as compared to other pups who had not undergone artificial insemination.
There is no other viable explanation except for the transfer of learning from mice fathers to pups through inheritance, since that was the only difference between the pups in the study. Additionally, the area of the brain responsible for processing smell, specifically those regions that respond to acetophenone, were larger in pups that had received mice sperm than normal pups. This modification of anatomical structure only in genetically engineered pups further supports the idea of genetic transfer of learning.
The missing links
However, the mechanisms through which learning in the brain is coded in the sperm is not known. There are nerves that are connected to gonads and various chemicals that are released in the bloodstream that may possibly play a role. Further studies need to be carried out to understand the exact mechanisms, as these ideas are a long way from being tested on humans!
These studies are an important breakthrough for improving our understanding of anxiety and phobias. Isn’t it strange that most of us are scared of insects? When you think about it, this fear makes perfect evolutionary sense.
Perhaps a few hundred years in the future, we will fully unravel this genetic mystery and crack the code to make super smart babies by transferring all the knowledge that previous generations have gained!
- Discover Magazine
- Study Shows How Epigenetic Memory Is Passed Across Generations – University of California, Santa Cruz
- Inherited Memory – Embry-Riddle Aeronautical University