Quote:
Over a lifetime, identical twins become less and less identical. At the gene level, they're still identical, but at the epigenetic level they begin to diverge at birth.
|
They can also diverge in utero. Just like one limb can grow longer than another, so can twins develop differently in the womb.
Pottenger's cats is a good example of epigenetics. Although at the time, they didn't understand that yet. From a natural selection point of view, epigenetics makes sense. If one generation is exposed to a certain hostile environment, it makes sense to develop defenses against this environment and develop the ability to transmit those defenses to the offspring so that the offspring is able to defend themselves against this environment from birth, thereby increasing the chance of survival of that offspring, and also the chance of reproduction of that same offspring in the same hostile environment.
However, what we mostly see with epigenetics is the bad sides of it, rarely the good sides. The most obvious reason for this is that we've never been exposed to the current hostile environment until very recently from an evolutionary point of view, thus we don't currently have any defense against it. For such defenses to be developed, it would probably take many more generations yet. The problem with this idea is that we do not die from this environment before we reproduce, therefore we reproduce our defenseless genes, and continue to suffer from the same hostile environment for generations. Instead of natural selection, we now have artificial selection. Man-made selection. This artificial selection comes mostly in the form of medicine.
Remember, natural selection works both by eliminating the unable, and reproducing the able. The unable are those who can't currently cope with the environment or who can't produce offspring, and the able are those who can cope or who can produce offspring who can cope by way of mutation. With medicine and other man-made artificial selection factors, we reproduce a whole lot more of unable than able.
In other words, epigenetics is a mutation which is a survival advantage within natural selection, but not within artificial selection. Logically, this means if we could temporarily disable epigenetics in the parents for the purpose of reproduction, we could produce offspring that could deal with our current hostile environment better than the parents. However, one implication of the above is that we could just ignore the hostile environment, and allow it to worsen to such a point that it would literally become lethal to us without having to disable epigenetics in future offspring.
That's the quick and dirty solution. Is there a less drastic solution? Of course. We revert to a previous non-hostile environment, or a less hostile environment. But where do we start? Easy. With the things we are most often exposed to, and have the most direct and significant effect on our physiology therefore on our epigenetics. Air, water, food. In descending order of collective-to-individual responsibility. There's more environmental factors like noise and light, but those are much less significant factors in my opinion. The problem with this less drastic solution is that it takes time. Generations. Maybe two or three. Just for the effect of those changes to be seen at the physiological and anatomical level. At the genetic and epigenetic level, the effects are almost immediate, if not at most a few years down the line. But when you're already grown up, that's it for that. You won't change how your nose looks. For your kids tho, they might just grow a more beautiful and more functional nose. Deviated septum ring a bell? Still, if we just think of obesity, that could be changed right off the bat in a year or less. If not collectively, at least individually.