If you have read the post on “ Why do we age and what can we do to stop it?” , you might like this Q/A post based on it.
This is a series of questions from one of my friend Leah who blogs at “The Modern Idiot “. I attempt to answer the same from my understanding of the subject:
So as we evolve, and adapt, and mutate through each subsequent generation’s environment with new diets, new toxins, new atmospheres, etc., are we aging faster or slower as a whole?
First off, we don’t not evolve fast enough to exhibit the stable, sustainable mutations in the immediate generations that follow as we have a relatively large lifespan. These mutations are generally easily evident in populations of bacteria because they have very short life cycles. For us, it would take 1000s of years to make any marked evolutionary difference in our population.
But if you take the Ecuadorian community I wrote about in the post as an example, there is was seen that the entire population with that specific gene mutation came from a common progenitor who had that mutation AND THE MUTATION WAS STABLE enough to be passed on to subsequent generations.
Further more, it can also mean that a defect in one copy of the gene was enough to cause a deviation from the norm. Here the other gene (the copy received from the other parent) was suppressed or masked.
Another point to be mentioned is there are two types of mutations that can affect your body. One that can affect your somatic cells (general cells of the body like skin cells, liver cells etc.,). This type of mutation can affect you only during your lifetime and is not passed onto the progeny.
The mutation has to reach the germ cells (sperm or egg cells) to alter the genetic data and if it is a stable one, be passed off in to the subsequent generations. (Mutation is nothing but the altering of the nitrogenous base sequences present in the DNA. These bases are of 4 types and are denoted by A, T, G, C and have specific base paining capabilities. This coding mechanism thereby codes specific proteins that are needed for our survival and proliferation. So if any of these bases are changed at any part of the DNA , the protein code is altered and this might lead to bad products or protein misfolding and a general impediment of normal functions. Sometimes, mutations can be reversed. For example a mutation caused by UV can be reversed by near-UV light and so on. There fore, I mentioned the fact that the mutation has to be stable enough have any observable changes.)
Are we aging faster or slower as a whole? Can this be determined with accuracy?
Human lifespan has increased because we can now cure many diseases that were the main cause of death earlier. WE have also become more conscious and aware of what’s good and what’s harmful.
Since the current biomarker to calculate the aging process is the telomere, we can have statistical data concerning the recent times but since these are fairly recent developments, I don’t think we can statistically determine whether the rate is faster or slower as compared to maybe even 200 years ago. This is my opinion as far as the biomarker strategy is concerned.
I guess we can calculate the data obtained from a group of individuals living in different geographical locations and having different lifestyles and get an estimate. This kind of studies is sometimes done with twins who have the same genes but exhibit different traits due to different environments. How our genes will express themselves is determined by external environments to a great degree.
Are we also passing on damaged DNA to create increased susceptibility to mental disorders, disease, etc.?
If there is a germ-line mutation (in some egg/ sperm cells) and is stable enough, there are high chances of it being transferred to the next generation. Now the fact remains, the mutation has to be stable enough and also whether the disease you are dealing with is caused by the alteration of a single gene/ product. Sometimes, its a complex interplay and interaction between a variety of genes/cells/organ systems in order for the disease to develop.
If we are passing a defective gene that is stable and is detrimental for the child, in future we might be able to screen and alter the damaging effects by gene therapy in the unborn kids (this is currently happening but theres a lot of problems and ethical issues attached with it). There are also many gene therapy practices for cancer and other diseases but the outcome is not always desirable. Its still under works.
Cheers! PART 2 OF THE Q/A LIST TO FOLLOW SOON..
©2013-2015, The Idea Bucket. Written By ANANYA. For more background info, please refer to this post: “Why do we age and what can we do to stop it?”