The Foresighted Paradigm Shift
|July 26, 2009||Posted by Patrick under Evolution, Biology, Intelligent Design, Genomics|
I’ve heard geneticists say we’re in the middle of a paradigm shift, and that no one really understands what’s going on. I even read an article the other day showing how at least one creature DELETES portions of its own DNA during certain stages of development. Basically, the long-held ideas from even a couple years ago are being modified. Until scientists can look at an arbitrary line of code and say “this does this or that” I would not say any idea is “certain”.
Lamarck’s specific hypothesis had been rejected once Mendel found a mechanism for inheritance. Lamarckism was so obviously wrong. Darwin came up with something that was just the opposite. It was obviously true and easily understandable. It is easy and true within a certain scope, although it’s inadequate to explain certain biological features. Hence the modern synthesis and the current attempt to formulate a new synthesis of ideas, which may or may not succeed.
Engineers will often design functionality that goes unused unless particular stimuli causes a triggered event (a function that is generally unexpressed except under certain conditions triggered by other functions or changes in input/system). I believe that such observations could be an avenue for research: looking for foresighted mechanisms. And we know some do exist. E. Coli don’t just react to changes in their surroundings — they anticipate and prepare for them — when switching from aerobic (oxygen) to anaerobic (oxygen-less) respiration. There have been other discoveries discussed on UD, but they’ve mainly been pertinent to single-celled organisms.
But based upon epigenetics studies a new version–which is smaller in scale/effect–of Lamarck’s basic idea is making a comeback. I looked up what’s been reported more recently and I can’t say I’m too surprised:
The effects of an animal’s environment during adolescence can be passed down to future offspring, according to two new studies. If applicable to humans, the research, done on rodents, suggests that the impact of both childhood education and early abuse could span generations. The findings provide support for a 200-year-old theory of evolution that has been largely dismissed: Lamarckian evolution, which states that acquired characteristics can be passed on to offspring.
Silencing DNA: Adding methyl groups to specific spots in the genome can alter the expression of marked genes. The process, known as DNA methylation, is one mechanism of epigenetic change, heritable change that does not alter the sequence of DNA itself.
“The results are extremely surprising and unexpected,” says Li-Huei Tsai, a neuroscientist at MIT who was not involved in the research. Indeed, one of the studies found that a boost in the brain’s ability to rewire itself and a corresponding improvement in memory could be passed on. “This study is probably the first study to show there are transgenerational effects not only on behavior but on brain plasticity.”
Cabbage looper caterpillars (Trichoplusia ni) are able to alter the expression of genes associated with metabolism, homeostasis and immunity in response to feeding on plants carrying bacteria. New research has shown that, as well as tailoring gene expression within their own digestive systems, the insects are able to pass this information along to their offspring.
I’m sure there are other examples, but I did not search any further. Please post links to other research along similar lines.