Newsweek
Michael Skinner has just uttered an astounding sentence, but by now he is so used to slaying scientific dogma that his listener has to interrupt and ask if he realizes what he just said. Which was this: “We just published a paper last month confirming epigenetic changes in sperm which are carried forward transgenerationally. This confirms that these changes can become permanently programmed.”
OK, so it’s not bumper-sticker-ready. But if Skinner, a molecular biologist at Washington State University, were as proficient with soundbites as he is with mass spectrometry, he might have explained it this way: the life experiences of grandparents and even great-grandparents alter their eggs and sperm so indelibly that the change is passed on to their children, grandchildren, and beyond. It’s called transgenerational epigenetic inheritance: the phenomenon in which something in the environment alters the health not only of the individual exposed to it, but also of that individual’s descendants. [...]
Michael Skinner has just uttered an astounding sentence, but by now he is so used to slaying scientific dogma that his listener has to interrupt and ask if he realizes what he just said. Which was this: “We just published a paper last month confirming epigenetic changes in sperm which are carried forward transgenerationally. This confirms that these changes can become permanently programmed.”
OK, so it’s not bumper-sticker-ready. But if Skinner, a molecular biologist at Washington State University, were as proficient with soundbites as he is with mass spectrometry, he might have explained it this way: the life experiences of grandparents and even great-grandparents alter their eggs and sperm so indelibly that the change is passed on to their children, grandchildren, and beyond. It’s called transgenerational epigenetic inheritance: the phenomenon in which something in the environment alters the health not only of the individual exposed to it, but also of that individual’s descendants. [...]
Chemical life experiences. The notion that this says much about passing on acquired middos genetically, not just through chinukh, is quite a stretch. Newsweek is playing language games.
ReplyDelete-micha
Micha, what makes you so sure that only chemicals cause epigenetic changes? It would seem to me that that is actually untrue, scientifically.
ReplyDeleteOxidative stress is a major component of many neurological diseases occurring in old age. This is well-established. And that is not necessarily chemically-induced. It is one of many things that can lead to epigenetic changes which contribute to these disease pathologies. This is an area of research which needs more study, but I wouldn't rule out emotional states and the like having effects in this avenue. In fact, the article itself points out that non-chemical stressors (such as an instance of overeating) similarly produced a genetic 'imprint.'
One has to suspect that highly traumatic experiences will also leave their mark in this sense. I only wonder, if it does leave an imprint, if the resulting evolutionary mechanism is one that benefits the offspring (ie as a protective mechanism), and if so, how does it do so. (It is certainly possible that it will negatively influence offspring - wouldn't that be interesting).
I bet Skinner had a heck of a time getting his theories taken seriously.
ReplyDeleteI don't know what is true and what isn't. I only am commenting on the article.
ReplyDeleteSkinner's study was of "exposing rats to a fungicide called vinclozolin". And the article adds "Other labs, too, are finding that experiences—everything from a lab animal being exposed to a toxic chemical to a person smoking, being malnourished in childhood, or overeating—leaves an imprint on eggs or sperm, an imprint so tenacious that it affects not only those individuals’ children but their grandchildren as well."
Just speaking about what the article says (since I don't know anything else about the topic), that does not establish that behaviors leaves an imprint. It establishes that chemical and biological changes do.
As the article itself defines the limits of the phenomenon, "something in the environment alters the health not only of the individual exposed to it, but also of that individual’s descendants."
The whole thing sounds very Lamarckian to me.
-micha
The next step would be to:
ReplyDelete1) show similar epigenetic effects in more purely "psychological" life changes. For example, stress can be induced in rodents quite easily.
2) show what genes, in particular, are affected.
3) show that the offspring have measurable differences.
4) link the changes in gene expressing to those offsping differences (e.g., see if the particular offspring with the differences indeed have the expected epigenetic changes and the other normal offspring don't, or artifically change the expression level of the identified genes and see if the differences seen in the offspring can be recapitulated in normal subjects.)
5. some aspects can be done, to a limited capacity, in people as well.
Micha -
ReplyDeleteThere are aleady some evidence on life experience more complex than fungicide exposure having effects on offspring. The second page of the article goes into it a bit more. It's only a matter of time for genetic experiments similar to the fungicide experiment is done in, e.g., mice grown in enriched environments (where neurological effects in offspring are already documented).
One man's scientific heresy is another man's refining of an accepted model. Dr, Skinner's research looks like important work, and it is indeed very interesting to see that Lamarck, in the end, was not totally wrong (http://en.wikipedia.org/wiki/Lamarckism). But I doubt there is anyone out there predicting the complete overturning of the modern understanding of the mechanisms underlying heredity as a result of his findings.
ReplyDeleteBetzalel: You can easily check Dr. Michael Skinner's pulication record. Go to Pubmed, the NIH's main database for research articles in the biomedical sciences (http://www.ncbi.nlm.nih.gov/pubmed),
and search for "skinner M AND epigenetic AND washington". You can see that he has a perfectly respectable publication history - including a 2005 paper in Science, which is arguably the most respected (and very mainstream) American journal for the reporting of original scientific research.
I think the best confirmation of epigenetics is the Jewish people. The genes of Ashkenazim have more in common with those of Yeminite Jews than the genes of Ashkenazim have with Christian Europeans, yet Ashkenazim have physical features which look more like Christian Europeans than Yeminite Jews.
ReplyDeleteSimilarly, Iranian Jews look more like Iranian Gentiles than Askenazi Jews, yet they are genetically more similar to Ashkenazi Jews.
I always wondered about why the Jewish people didn't follow the predictions that I learned in my high school genetics class. I always thought that the reason was because of large numbers of converts changing the genetic pools of different Jewish subgroups, but then I read that the genetic pools of different subgroups of Jews were very similar. Now with this new theory of epigenetics, it all makes sense.
Betzalel,
ReplyDeleteMy cousins kids, botrn in Israel, look Israeli. This change is so fast, I don't think it's even epigenetics which would require a second generation. I think it shows the effects of environment and body language on development -- how much of a person's appearance is shaped by something other than genetics.
-micha
Micha,
ReplyDeleteMeah Achuz. I feel that Hashem has set things up this way in order to create potential for assimilation and the to therefor reward those that don't. It well answers those that want to deny our middle-eastern ansestry.
Michoel