Cost Versus Benefit When It Comes To Evolution

How does the body know what to turn on where? In the liver, only the parts of the molecule relevant to the liver turn on, while the rest of the molecule sits dormant. These molecules can come from the environment, and they can be inherited. They have a profound impact on the expression of genes, for good and for bad. Remember how I just said these compounds can come from the environment? It’s about our environment too! Epigenetics would be as if someone used a marker to cover parts of the letters or words so they couldn’t be read, or highlighted certain parts to emphasize their importance. Again, epigenetic influencers don’t alter the genes themselves, but they do change the way those genes are expressed. Lamarck has been ridiculed in biology circles for nearly two centuries, but in a way, he was correct! Acquired traits can be passed on. And it’s because of epigenetics. Eventually, the mice would shake from fear when exposed to the scent, even in the absence of a shock. The researchers even identified the actual brain changes responsible for the scent response. Your father’s gym habits could have affected your intelligence. Your mother’s smoking habit could be affecting your lungs. Your grandfather’s lifestyle choices could be impacting your life expectancy.

Prisoner Of Life

Your parents’ fear of dentistry could be making you fearful too. If the environment is affecting how genes are expressed, what in the environment is having the greatest impact? There are so many environmental factors to consider, like exercise, smoking, and stress, but another big one, maybe the biggest of all, is diet. We put food in our bodies every day. Our digestive systems break that food down into the building blocks of our bodies. Put simply, our diet and lifestyle choices matter a lot more than we may have imagined. Once again, let’s continue with our house analogy. If you use subpar materials, or cut corners during construction, you’re going to have problems. The roof might leak, the windows will be drafty, the drywall will crack, and the pipes will burst. Your house will deteriorate quickly, and if you planned to live there, you’ll be in trouble. Your body is just like that house. If you eat subpar foods without enough vitamins, minerals, and other essential nutrients, you’re going to have problems. Your mouth might not develop correctly, your body will be weaker, and you will be more likely to succumb to illness and the ravages of age.

The Center of Attention

If you planned to live a long, happy life in that body, you’ll be in trouble. The fact is, we have a long way to go to understand exactly how most epigenetic changes affect our health and our children’s health, but we are learning more every day. The most important takeaway is that our habits and lifestyle choices really matter when it comes to the health of our babies. Eating healthy, exercising, and yes, taking care of your mouth, can positively influence your epigenome. There are birds in the area, but most don’t have beaks sharp enough to break the beetles’ shells, so they can’t digest them. Many of those birds die of starvation before they reach reproductive age. Those babies grow up, and most of them also have sharp beaks, because their parents did. Sharp beaks get reproductively selected for, and, over generations, all the birds in that area have sharper beaks than their ancestors. This is how Darwinian evolution works. The environment puts pressure on the animals that live there, and that pressure influences the evolution of those species of animals. The creatures that can survive the challenges have babies. The creatures that can’t, don’t.

Moving On

There is often a cost versus benefit when it comes to evolution. Changes present their own challenges! For example, the first hominins in Africa, a variety of species that later evolved into humans, started walking on two legs around four million years ago. This led to an increased learning capacity and enhanced motor skills. But, as our brains grew, our faces became more vertical, and our mouths became smaller. Then, about a million years ago, there was another big shift. The larynx in the throat descended relative to the soft palate. This vastly improved speech, something that has allowed us to advance far beyond all other animals. But it also resulted in a rearrangement of parts of the throat and airways, making breathing and swallowing less safe and more challenging than it is for other animals. That’s why it’s relatively easy for humans to choke, why a drink can shoot out of your nose when you laugh, and why many of us have airway problems like sleep apnea. But, in the scheme of things, those are reasonable prices to pay for the ability to talk. And without optimal nutrition and lifestyle habits, these problems have been compounding. Our mouths have continued to get smaller and smaller, and it’s not all because of genetics. The advent of stone tools to cut food and cooking to soften it reduced our ancestors’ need for larger jaws. The transition from foraging to farming followed by the Industrial Revolution further expedited the miniaturization of our mouths. When it comes to muscles, you use them or lose them. And our bones respond to mechanical loading during growth. When we eat soft foods, it weakens our jaw muscles and bones, and results in smaller mouths.23 Before the Industrial Revolution around 200 years ago, impacted wisdom teeth were almost unknown. Today, over 70 percent of us suffer from them. Once upon a time, our larger jaws provided plenty of room for our teeth. Today’s children have such crowded teeth that more than four million Americans now wear braces at any given time. I see this in my own practice. I’m frequently asked by parents why they have straighter teeth than their children. Simple sugars, and empty calories don’t support our cells and microbiomes the way they should, and this impedes the healthy growth and development of our mouths and facial structures.