Slashdot Mirror
Acquired Characteristics May Be Inheritable
A story from a week or so back in Technology Review describes research coming to the surprising conclusion that Jean-Baptiste Lamarck may have been right — that acquired characteristics can be passed on to offspring, at least in rodents. Lamarck's ideas have been controversial for 200 years, and dismissed in mainstream scientific thinking for nearly that long. "In Feig's study, mice genetically engineered to have memory problems were raised in an enriched environment — given toys, exercise, and social interaction — for two weeks during adolescence. The animals' memory improved... The mice were then returned to normal conditions, where they grew up and had offspring. This next generation of mice also had better memory, despite having the genetic defect and never having been exposed to the enriched environment."
Article doesn't say what interactions the adult mice had with their offspring. The benefit may have just been passed to the next generation through regular learning, modeling, etc.
I don't know about lab mice, but rat packs have a pretty complicated social structure (for example nominating food tasters to try new sources of food) so I'd bet that mice can teach their young a lot more than researchers might suppose.
Here's my personal suggested mechanism.
Enriched environments have long been known to make mice 'happier' in addition to being better at solving various tests, and having larger brains, etc. This stress-reducing effect has been known to be maintained long after the rats are removed from the enriched environment.
The change in the mother rats should fully be expected to be partially shared with the pups. The womb is not a completely separate environment that just happens to exist inside the mother, her experiences shape what sort of chemicals(beneficial or detrimental) are delivered to the baby.
A healthier, less stressed out mother is likely to nurture her babies properly while they're in utero, and uterine environment that's not bathed in stress hormones is generally a preferable one for the baby's neurological development.
TFA also mentions that an opposite effect occurs, where highly stressed mothers had babies that then also abused their pups tend to have pups that themselves are poorer mothers. They don't mention if problem solving tests were given to these rats, but I'd fully expect that they'd show deficits in tests of memory and intelligence.
The researchers in the article say that this is a completely shocking discovery, I'd be shocked if it didn't happen. The stress response affects not only the mother, but also the baby, and those changes can be noticed in their later lives. Quel surprise.
This is an unfortunate shortcoming of science at the moment. A tested result is rejected until there is a suggested mechanism; as soon as a mechanism is suggested, it is all too often treated as "true" even if the mechanism itself has never been experimentally tested at all but was just plucked out of the air. The one that instantly springs to mind is the 2005 result that being cold can after all make you susceptible to catching a cold. The paper is reasonable and itself admits that its "suggested mechanism" (that capillaries in the nose constrict, reducing access by the immune system) was not itself tested by the authors, but was just an idea they came up with when their actual experiment -- do people sitting around with their feet in bowls of icy water catch colds more often -- gave a positive result. Nonetheless, that mechanism very quickly started getting bandied around as if it were gospel.
Females have all the eggs made before they're born, so how could the genetic material in them be affect by the conditions that the mother grew up in? Sperm DNA seems like it could be modified by the father according to living conditions, but it seems odd to think that environmental information in the brain would be passed down to the testes and such... It seems more plausible to think it's just the mice had a better mother.
How is that a shortcoming of science?
1) The researches found a result.
2) Proposed a possible mechanism.
3) Stated the mechanism was untested and might just be bullshit they cooked up at the pub.
4) People misreport guess of researchers as "Fact!" ...
6) "Shortcoming of science!" (and profit?)
It's sort of like saying that the urban legand "People think we only use 10% of our brain even though research has shown this to be almost certainly false." is a shortcoming of science.
People talk. People like to have "all the answers". The problem is with gossip not science. 'Science' hasn't ruled on the subject yet. The official stance of 'science' is that the mechanism is unknown.
Just as 'science' has only found that mouse mothers subjected to certain conditions can pass along the effects to their children even after the conditions have ceased. The mechanism should be discovered before any other conclusions can be reached. The summary is attempting to assign far more consequence to the study than study can provide. The shortcoming is with vague and speculative reporting not science. /rant
"This is an unfortunate shortcoming of science at the moment."
I agree with most of your post but disagree with your conclusion.
Contrary to the GP's claim there is no requirement in science for a "suggested mechanisim", the results of the experiment are far more important than the explaination. For example, nobody has yet explained gravity but few doubt it exists and that we can acurately predict it's behaviour via models.
However it is common practice for papers to offer (clearly labelled) speculation in the hope that "someone else" will look for evidence and cite your paper if they find it. A failure to understand the difference between clearly labeled speculation and repeatable experimental results is definitely a "shortcoming" but it is not a "shortcoming of science". Worse still the "shortcoming" of which you speak is often indistingushable from willfull ignorance.
"A tested result is rejected until there is a suggested mechanism" - This is simply false.
IMHO the "unfortunate shortcoming of science" is the apparent inability of it's philosophy to rate a mention in high school science classes. This is not due to a lack of trying, see: Sagan, Dawkins and Randi. My own SPECULATION as to why is it so, is that most people ( including the majority of educators ) simply want certainty and cannot accept a philosophy that shuns it, so the philosophy part is ignored and science becomes a library of factiods that are discovered via inspiration, rather than found via critical thinking.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.