Inheritance of acquired characteristics:
I liked both the movie “Young Frankenstein” and the published screenplay. Since I read the screenplay first I rather like it more. And there are a very few scenes in the book I felt were underplayed in the movie. Principally there is a scene in which professor Frankenstein is giving a clinic (that’s a lecture in which a patient is presented) for a number of Johns Hopkins students. I know that because Frankenstein was professor of neurosurgery at Baltimore General Hospital; I was head of neuroradiology at Baltimore City Hospital at the time. Of course I felt a sort of kindred spirit. And the Hopkins students and house staff were, how can I say this, not exactly rude, but brilliant and rather inclined to give you opportunities to make an idiot of yourself. The years there did nothing to improve my sweet temperament.
The good professor was interrupted by a question referring to his grandfather’s work, which was the reanimation of dead tissue of course. Young Frankenstein was having none of it, but the students persisted. Finally one mentioned an experiment in which someone had dropped pieces of vermicelli into water whereupon they began so stir with a life of their own. For an instant an insane light came into the professor’s eyes; then he pulled himself together and asked whether that was vermicelli the worm or vermicelli the noodle. I sometimes feel like that light gets into me as well.
Recently I was chatting with an unusually alert friend describing what is being done with epigenetics. He brightened and acted slightly scandalized and said, “Inheritance of acquired characteristics.” And so it is. Epigenetics is the study of the control systems of genes. They are changeable from generation to generation and are to a degree inherited.
The idea is not new. Around Darwin’s time there was the belief, and I believe Darwin entertained the notion, that when you use an ability you improve in that ability and are able to pass it on. Thus a blacksmith builds strong muscles and his children tend to be more muscular than if he had been a couch potato. The phenomenon was mediated by something called “pangenes” that resided throughout the body and at the moment or orgasm rushed to the gonads to be included in the new life. The intensity of orgasm, it was suggested, was the sensation of this rapid migration.
Alas the pangene is gone with the Dodo. There are few new ideas, and almost all of them prove wrong in the end.
Fairly recently it was discovered that some small animal or microorganism – I do not have the reference – could be exposed to heat and its progeny would have an altered sensitivity to a certain chemical. That is inheritance of an acquired characteristic sure enough, but unlike the pangenes of yore that which is inherited has little to do with what induced the change.
There is now something just a trifle closer to the mark. (The Seductive Allure of Behavioral Epigenetics, Greg Miller SCIENCE vol. 329 no.5987 July 2, 2010 page 24) It is a review article, and the title, more than the article itself it seems to me, suggests I am not the only one who has lit up at the notion of passing memories to subsequent generations. No, they don’t suggest that, but who can read another’s eyes? It’s easy in the book, but the movie did not attempt to portray it.
The experiment in question was that some female rats were stressed in a fashion that caused them to take less scrupulous care of their offspring, and it was found that the female offspring themselves were rather neglectful in the same way. When I mentioned this to another friend (I have few friends and I impose on them this way all the time), she said, “Well that has nothing to do with people. When did a rat ever have to meet a mortgage payment?” I responded that the stress was in fact depriving the mice of suitable nesting material and we had a good laugh.
The response to stress appears to be mediated by methylation of DNA, so it is epigenetic. What is missing is any mechanism to transfer that alteration of DNA to the gonads. The pangenes are still missing. The offspring rates are neglectful because of their own experience, not that of the mothers.
So I am still not buying into the inheritance of memories although if anything were to be transmitted thus, it would most likely be some impression of the parents’ own parents.
Still the dramatic tone of the title of the article suggests that somebody else has that wild look in the eyes.
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