I’m wondering if the same is true in humans? If so, some dogmas in science would have to be turned upside down. Please read about the test mice:
Certain fears can be inherited through the generations, a provocative study of mice reported recently. Researchers studied the epigenetic inheritance in laboratory mice trained to fear the smell of acetophenone, a chemical the scent of which has been compared to those of cherries and almonds. The researcher wafted the scent around a small chamber, while giving small electric shocks to male mice. The animals eventually learned to associate the scent with pain, shuddering in the presence of acetophenone even without a shock.
This reaction was passed on to their pups. Despite never having encountered acetophenone in their lives, the offspring exhibited increased sensitivity when introduced to its smell, shuddering more markedly in its presence compared with the descendants of mice that had been conditioned to be startled by a different smell or that had gone through no such conditioning. A third generation of mice — the ‘grandchildren’ — also inherited this reaction, as did mice conceived through in vitro fertilization with sperm from males sensitized to acetophenone. Similar experiments showed that the response can also be transmitted down from the mother.
Even assuming these findings are real and sound (a cite would be nice), inherited behavioral tendencies are not memories. We all have inherited behavioral tendencies. If someone touches a red hot stove they will quickly do their level best to stop touching it. That is an inherited behavioral propensity, coded into our genes. It does not involve a memory in any of the normal senses of the word: in the sense in which I remember my mother, or my telephone number, or how to ride a bike, or what I did last week. Neither does an aversion to acetophenone that is passed on epigenetically (even if such a thing really happens) amount to memory in any of those normal senses.
ETA: OK, ninjaed on the cite. I am still skeptical. I remember the Worm Runners Digest.
There was a finding once many years ago that Planaria could be taught Pavlovian responses, then ground up and fed to other Planaria who would acquire the knowledge.
I read this paper recently - or one very similar to it - and it’s not quite as mystical as it sounds. It’s more about regulating the level of the smell receptor, and in that light, it makes sense. If the parent finds a particular smell receptor useful during its lifetime (as measured by the fact that it was used a lot*), then it’s likely that the next generation or two will find it useful too. This is what epigenetics does - it transfers regulatory information from generation to generation.
The most surprising, and still puzzling, bit is that there appears to be a mechanism for measuring how often a particular receptor is activated and somehow communicating that to the gene activation and epigenetic mechanisms. We don’t know yet how that works.
In light of the above I find the following disturbing:
“using…23 types of subjects including, in addition to the flatworm and standard lab rat, octopuses, praying mantes, baby chicks, kittens and honey bees.”
But there was a recent experiment showing that the worms retained info after having head cutoff and regrown, so there is something interesting going on there.