- Marcus Mata
What is the process of aging? In terms of science aging may be seen as the process by which our bodies processes of upkeep slow down, and the body accumulate damage from normal process. Many people think of old age as an integral part of life, a natural occurrence. However, what if I told you it wasn’t as inevitable as we thought?
In the beginning of the 20th century the average human life expectancy was 40 years old, compare that to now where the expected human life span is 78.7 years, it has almost doubled, this has been in thanks to numerous medical breakthroughs and improvements in treatment as well as overall an improvement in our general quality of life, furthermore we can infer that this number is only going to increase as our understanding of medicine and aging increase. There will come a point when we as a collective should ask ourselves the biggest question in all human history- Should we age? Of course, many people shudder at the thought of this- without the urgency of old age in our youth, why would we do anything at all? Without the knowledge that one day we would be old and unable to do certain activities or experience certain things, would we even find purpose or meaning in the trivial tasks of living? These arguments may all be valid to some, but to me I feel that to truly know what you want to do, you must look at it as something that you would want to do without the thought or feelings of urgency.
While old age may seem like something that all organisms must experience you may be surprised to know that there are organisms that already have surpassed the process of aging and attained a point of perpetual youth. Animals like lobsters with their self-repairing DNA, Jellyfish with their infinitely repeating life cycles as they go through the process of infancy, adulthood, old age and then right back to infancy. In this blog post I shall be exploring the mechanisms by which these organisms “infinitely” sustain themselves and how potentially it could be applied to humans.
Lobsters and their super supply of telomeres:
Whenever a normal cell divides there is the chance that errors in genetic replication occur- these can be due to any number of reasons and are not really preventable, as such cells developed a certain mechanism by which to protect themselves from genetic mistakes and general oxidative damage to the DNA. Instead of the DNA essential to you being damaged and invertedly causing more problems in the replicated cell, the damage accumulates over time in the end of your chromosome – a part known as the telomere. Over the course of one’s life these telomeres continually get shorter and shorter, eventually reaching a point where they are too short or even non-existent, at this point typically the cell reaches a point of senescence- a state where they can no longer replicate, or a point where the cell continues to damage its genetic material more and more, and eventually ceases to function in a normal manor. This does not happen in the case of lobsters. Lobsters have a gene that codes for a particularly important enzyme- telomerase, which regenerates telomeres and allows the lobster to be functionally “immortal” and impervious to the process of old age. While I wish this was the end of the story, in the case of the lobster there is a very big “IF”. It is true that they are impervious to old age, however as a lobster ages it continues to get bigger and bigger, requiring it to molt at every stage in which it no longer can use its shell.
For the lobster, the process of molting is very exhausting and during this process, it is most susceptible to pathogens or even predators from external conditions. As such a lobster does have an “age limit” when the process of the lobster dies as the process of molting becomes too energy consuming and it simply dies of exhaustion during the process. If we are to genetically engineer the gene that codes for telomerase in lobsters into humans, it is likely that we would actually be able to live without a regard for age and without a point in which our bodies start to degrade on us.
The infinite Jellyfish; Turritopsis dohrnii
While it may be a much simpler form of life, this jellyfish is the only known biologically immortal specifies that there is. These jellyfish’s impressive life cycle begins with a fertilized egg, these grow and into a planula larva, from here they float around and once given the correct opportunity attach to a solid surface such as a rock or even ship hull where it continues to grow and develop. After some time, it breaks away from the surface it was attached to and becomes a fully formed adult capable of sexual reproduction. From this stage it no longer ages or experiences any process of degradation, however in the case that it is subject to environmental stress- it breaks down most of its cells and converts to a stage similar to the planula larvae. And from that point its life continues leaving it as “biologically immortal”.
While I do find it important to mention that it is extremely unlikely that we would be able to take this process and modify it to be applicable to humans (Imagine your grandparents suddenly reverting to babies and you would have to take care of them), it is still extremely interesting and important to look at and give perspective of the numerous and wonderous ways in which life goes on.
Interesting read!