Identical twins: Most of the time, identical twins become very different as they age, this happens because of the environmental factors as they grow up, change the epigenetic tags that they were born with, until they are two very different people, with very different epigenomes.
Some of the many environmental factors that could come into play are the twins diet, the activities they take part in, stress levels, and the introducing of toxins to the body. say one twin eats turkey sandwiches, rides a bike everyday, is very laid back and works at a bookstore or herbal shop, and has taken a few puffs of a cigarette in its lifetime, has a twin that eats only hamburgers from Mc.Donald's, stays at home watching T.V. on its time off, has very high stress levels from work, and drinks, smokes, and does drugs constantly, the twins are going to be very different people as they mature, and as their epigenomes take shape of their daily lifestyles.
Some people are born with certain epigenomic tags, passed down from mother or father, these tags have escaped being wiped from the epigenome, and are called "imprinted" genes. This specific kind of gene is passed down through the generations, whether it hinder or help the parties involved, when genes are passed down from parents to offspring, all of the epigenomic tags are removed, and erased, imprinted tags aren't erased, and passed down.
Depending on whether or not you get the nutrition you need, or if you get a few imprinted genes thrown in here and there, even if your raised in the himalayas or in downtown new york city, the environmental factors around you will change you, and others around you, differently, and by the end of your lives, if you had an identical twin then you would definitely be able to see the differences.
Lick Your Rats
Studies done show that rats with high nurtured childhoods,( were the mother licks them a lot) are shown to take high stress better, be more laid back, and recover from stress very easily, while low nurtured rats, are highly susceptible to depression, diseases, and don't recover from stress as easy as their low stress counterparts. The mothers licking actually activates the rat pups GR gene more, from the stronger signals sent to the epigenomic tags to activate the gene. In a rat, when stressed out or in a dangerous situation, its brain sends signals to its pituitary gland, and from there to its adrenal gland, when the signal is taken at the adrenal gland, the gland starts to produce adrenaline and cortisol, when the cortisol reaches the brain, the brain stop sending signals to the different glands, and stops the production of cortisol and adrenaline. Inside the brain there is a structure called a hippocampus, its job is to manage the stress of the rat, in this structure however, the cells produce varying levels of the GR gene, depending of how the rat was nurtured, the better nurtured, the more GR genes. when the cortisol is released into the blood stream, it binds with the GR genes sending a signal through the body saying "Calm down", as you can guess, the less GR and cortisol combos there are, the weaker the signal, and the longer it takes to recover from stress.
This can also work for human mothers and their newborn children, the more contact that is made with mother and child, the more of a chemical called Oxitocin is produced, and that allows for a happier mother child relationship, as well as reducing stress levels in both mother and child. The same way for humans and their dogs, scientists in different countries had a few experiments were they took blood samples from dogs and their owners during a petting session, and measured them for oxitocin, the results were about the same for a mother and her breastfeeding child, a sudden boost in oxitocin levels was discovered, the reaction i would imagine is the same for social interaction between good friends, boyfriend and girlfriend, and parents with their children, (sometimes)
Nutrition and the Genome
the food we eat, and possibly the food our parents eat can affect our epigenomes in different, and very unique ways. For example, say you eat three apples, a healthy serving of yogurt and cheese, and generally have a very healthy diet, your epigenome will be much different from that of an unhealthy slob who lives with five other people in one apartment on the top floor, who has to wade through the dirty clothes and messes made by the people they live with, like all of the top ramen® bags that seems to be the only thing they ever eat, some epigenomic tags however, are passed down as imprinted genes, that may carry diseases or other nasty ailments, but may also carry some benefits, say your parents had diabetes, it may not matter if you lived the lifestyle of the healthiest person in the world, you still have a good chance of having diabetes from the passed on epigenomic tags your parents gave you. This is how both your diet, and your parents can affect your genome and nutrition levels.
Epigenetics and the human brain
there is a substance out there that can actually change you GR gene at a young age however, so don't worry if your rat is a bit agro, this chemical is called methyl, and depending on whether or not your GR gene is activated or not, this substance can reverse it, if it is taken out, or put into a rats brain, it can reverse the GR gene, or find the healthy medium between the two. Depending on what toxin it is, and how much is administered, it can change the methyl groups that hold your GR gene together, or keep it apart(activated or deactivated) or it can end up screwing up your brain so badly, that you could completely misinterpret a situation, and your body could be sending all the wrong signals, at all the wrong times, so remember kiddies, Be Smart! Don't Start!
