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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."
Lamarck is one of those guys who's name is generally synonymous with bad science (he's about as villified as Darwin is deified). I'm actually a bit (pleasantly) surprised that someone would invest the time into this sort of study.
That being said, the article is rather short in one important area: a suggested mechanism for this sort of inheritance. Without that, it's bound to be mired in controversy for some time.
Here's the actual article.
We're just learning that Histone/DNA modifications can be inherited.
Histones (the spools around which DNA is stored) tell when the DNA source code should be 'active' vs 'inactive'. And these histones have a huge data space in the form of possible modifications (methylation, acetylation, etc.).
When DNA is replicated, these histones too are replicated at the same time. And they seem to be replicated in a semiconserved manner similar to DNA (half go to 'old' strand, half go to 'new' strand). And that there is a whole series of touring-like proteins that can 'read' 'write' or 'erase' these modifications.
If these modifications are made during an organism's life, they can be inherited by offspring.
Not only is the code being copied, but the 'marks' that tell which/when/where to read the code at any given time/condition too can be passed down. And that these marks can be written in real time rather than waiting for mutations in the code itself.
There was a recent study that XO females who inherited the X from their father had markedly different dispositions than those who inherited the X from their mother. DNA modification that is unique to how the male or female deal with their own X chromosome could be being passed down to offspring.
How about books? I know that parents barely try that anymore, but reading does that.
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.
Really, this is hardly a surprising result. There are many possible mechanisms that suggest themselves, operating either on the embryo or on the newborn - parents who are more intelligent are likely to be able to pass on more of what they've learned and/or provide a "richer" environment for their offspring, even if we're only talking about mice. The mammalian brain is remarkably plastic.
The real problem for the Lamarckian paradigm is that once you've optimized the environment, socialization, and gene expression for the animals in question, it's hard to propose a mechanism for making more radical changes through "acquired characteristics" - and in fact no such changes have been observed. This study does not change that fact.
The original article sounds to me to be altogether too credulous and sensationalistic.
Interesting eh? So how did it explained religion?
/.ers, it might not even matter if there's an abundance in the supply anyway.)
Is it where the first ones get all the good stuff and the offsprings only get to dream/think about it? Well I could understand that if the scenario was giving dozens of virgins to one guy, the rest would only dream about it. In that case it would be a supply and demand problem, not an inherited one. (or in our case as
In Soviet Russia, Lamarckism as interpreted by Lysenko in agriculture, was the state mandated approach and genetics was essentially outlawed until the 1960s. Geneticists were fired from jobs, sent to work camps, prison or just executed.
Learning HOW to think is more important than learning WHAT to think.
It could be one day possible to create a kind of device that harmonizes human beings early on in childhood development, increasing their awareness and understandings.
Beer.
I really hope it's not the case that results can be rejected due to the lack of a mechanism to explain them.
Darwin had no mechanism to back his theory of 'origin of species by natural selection'. The mechanisms people had theorized at the time were not really compatible with Darwin's ideas. It wasn't till Mendel's work was appreciated that people had a viable mechanism for the inheritance that fit with Darwin's evolutionary theory.
This was a common misconception until recently. You can read about it here.