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Is Immortality Possible or Is Aging Inevitable?

Some animals don't age; we may do likewise.

Old tortoiseOld tortoise

“Could humans become immortal?” is something we get asked quite often, and the answer depends on what exactly you mean.

When it comes to immortality, what you mean is important

Whether human immortality is possible greatly depends on how you define it. If you define it as living forever and being unkillable like in a comic book or movie, then, no, it is highly unlikely.

However, if you define it in terms of showing no decline in survival characteristics, no increase in disease incidence, and no increase in mortality with advancing age, then yes.ย 

To some people this may seem to be a matter of semantics, but it is not. The first is a science-fiction fantasy; the second is based on real-world biology that evolution has already selected for in certain species. This is known as negligible senescence. And in fact, some animals are already doing exactly this!ย 

And the good news is that there is no reason why humans could not enjoy considerably increased healthy longevity if the appropriate technologies are developed. It isn’t even beyond the realms of possibility that humans might achieve negligible senescence thanks to the march of medical science and technology.

Senescence and negligible senescence

Senescence refers to the gradual deterioration of aging and is typically very obvious in almost every species. More accurately, senescence refers to a decline of survival characteristics, such as strength, mobility, and senses, and age-related increases in mortality along with a decrease in reproductive capability. Mortality rates for humans and most animals increase dramatically with age beyond reaching reproductive maturity.

A few species are more unusual and exhibit negligible senescence. An organism is considered negligibly senescent (NS) if it does not show any loss of survival characteristics, such as strength, mobility, and senses, an increased mortality rate with advancing age, or a loss of reproductive capability with age.


Recorded lifespan

Rougheye rockfish205 years[1-2]
Aldabra Giant Tortoise255 years
Lobsters100+ years (Presumed NS)
Naked mole rat (Heterocephalus glaberis)28 years
Sea anemones60โ€“80 years
Freshwater pearl mussel210โ€“250 years[3]
Ocean Quahog clam507 years[4]
Greenland Shark400 years
Lake sturgeon (Acipenser fulvescens)152 years (Presumed NS)
Clams such as Panopea generosa160 years (Presumed NS)

Negligible senescence does not mean they cannot die

It is worth noting that even though these species enjoy negligible senescence and do not age or age immeasurably slowly, they are still vulnerable to predation, accidents, starvation, environmental dangers, changes to their environmental niches, and diseases. This means that extremely old examples of these species with negligible senescence are very rare, especially in the wild.

Some tortoises age very slowly, if at all

To further complicate matters, we often need to sacrifice the animal in order to measure its age by examining the deep tissues and marks inside bones, much like measuring rings in a tree trunk.

This means that we cannot know the maximum age that might be achieved by these species, so the above numbers are based on what information we have; there could well be considerably older examples out there. The point here is that negligible species with senescence do not deteriorate with age and may live considerably longer than has been recorded.

Possibly even more intriguing is the hydra, a species that is observed to have no lifespan limit, as it regenerates very quickly. Barring predation and changes to its environment, it is one of the few species for which the phrase โ€œbiological immortalityโ€ would be appropriate [5]. The hydra is quite unique in how its cells work, and it is quite unlike the majority of other organisms on the planet; it is a true oddball but fascinating all the same.

Strategies for engineered negligible senescence

Some Lobsters do not age like other species.

Well, this is great news if you happen to be a lobster and avoid the fishermanโ€™s pot long enough to reach a ripe old age, but what about us; how can we benefit from the same advantages that negligibly senescent species do?

It is clear that we would have to wait a long time, perhaps forever, before evolution selected the same traits in humans, so something a little more direct is needed.

Some scientists, such as Dr. Aubrey de Grey, propose that we can engineer negligible senescence by using a repair-based approach to the damage that aging causes. This is the basis of SENS, the strategies for engineered negligible senescence, and is being pursued by the SENS Research Foundation.

Other researchers have built on the original concept of SENS, and in 2013, the Hallmarks of aging was published. This landmark paper broke the aging process down into nine distinct processes known as hallmarks and essentially gave researchers a way to classify aging and an insight into what processes they might target to slow down or even reverse aging.

While there are quite a number of aging theories, the Hallmarks of aging appears to be the most popular, judging by how many times it has been cited and how often it is used in academia. Essentially, the Hallmarks of aging has given researchers a list of targets to develop therapies for and now the race is on to create them.

Should negligible senescence be achieved in humans through SENS or other approaches such as partial cellular reprogramming, it would potentially mean the end of age-related diseases and ill health, a most worthy goal indeed.

The inevitability of multicellular aging

Back in 2017, a great deal of fuss was made about humans achieving negligible senescence, with a number of articles suggesting that it is impossible. The reason is that the mainstream media has interpreted this paper very badly, assuming that the authors imply that because aging is inevitable, we cannot do anything about it [6].

The media was been filled with articles almost smugly proclaiming in some cases that aging is unstoppable and mathematically impossible to defeat. The problem with this interpretation is that it is just plain wrong. The original paper is, strictly speaking, correct in that aging damage is indeed inevitable, but it makes no assumptions about interventions. The publication says a great deal about what evolution has done and is likely to do based on observation, but that says absolutely nothing about what medicine may achieve in the future.

One cannot apply such thinking when it comes to engineering negligible senescence in humans through the periodic repair of age-related damage. So, quite simply, publications like this make little difference to work in this field, and they change the plausibility of us achieving negligible senescence in no way whatsoever.

No, aging is not inevitable

A more recent example in 2021, which was again met with almost gleeful declaration by the press that aging cannot be stopped, was the โ€˜invariant rate of ageingโ€™ paper [7].ย  Unfortunately, once again the reporting was based on the a similar misunderstanding of what the study actually said.

The study was actually not a study about longevity or that aging was inevitable. It was trying to understand what influences the rate of aging across species and how much results from evolved biological processes versus the effects of the environment. While the research itself has obvious merit scientifically speaking, the popular press chose to represent it in a different light.

The irony is that instead of showing that aging is indeed inevitable, the research instead shows that eventually humanity will run out of ways in which environmental improvements will increase our lifespans. At that point further gains will only be achieved through medical interventions that address the aging processes directly and either repair the damage aging does, or slow aging down by make us more resilient.

What if humans were immortal?

Imagine the possibilities that would come with living forever! You could spend more time with loved ones, master a variety of careers, and travel the entire world! If everyone on Earth were immortal, we’d all have a chance to recover from our mistakes, and our society could save a ton of money on healthcare


There is a clear difference between Hollywood-style immortality and negligible senescence, with the latter being a plausible goal in the next few decades. Evolution has already demonstrated that negligible senescence is indeed possible; now, the next big challenge is to use an engineering approach to aging to see if we can emulate in people what nature has done in a few lucky species. The good news is, we have a list of targets and a far better understanding of what aging is than we did even 10 years ago, and there is a lot more interest in tackling aging from both the academic and investment communities.ย 

If you enjoyed this, you may also like our video about the Marvel film. the Eternals. We explore if humans could live as long and age slowly as the Eternals for real.


[1] Munk, K. M. (2001). Maximum ages of groundfishes in waters off Alaska and British Columbia and considerations of age determination. Alaska Fish. Res. Bull, 8(1), 12-21. [2] Cailliet, G. M., Andrews, A. H., Burton, E. J., Watters, D. L., Kline, D. E., & Ferry-Graham, L. A. (2001). Age determination and validation studies of marine fishes: do deep-dwellers live longer?. Experimental gerontology, 36(4), 739-764. [3] Ziuganov, V., Miguel, E. S., Neves, R. J., Longa, A., Fernรกndez, C., Amaro, R., … & Johnson, T. (2000). Life span variation of the freshwater pearl shell: a model species for testing longevity mechanisms in animals. AMBIO: A Journal of the Human Environment, 29(2), 102-105. [4] Munro, D., & Blier, P. U. (2012). The extreme longevity of Arctica islandica is associated with increased peroxidation resistance in mitochondrial membranes. Aging cell, 11(5), 845-855. [5] Martฤฑฬnez, D. E. (1998). Mortality patterns suggest lack of senescence in hydra. Experimental gerontology, 33(3), 217-225. [6] Nelson, P., & Masel, J. (2017). Intercellular competition and the inevitability of multicellular aging. Proceedings of the National Academy of Sciences, 201618854. [7] Colchero, F. et al. The long lives of primates and the โ€˜invariant rate of ageingโ€™ hypothesis. Nature Communications (2021), doi: 10.1038/s41467-021-23894-3
About the author

Steve Hill

Steve serves on the LEAF Board of Directors and is the Editor in Chief, coordinating the daily news articles and social media content of the organization. He is an active journalist in the aging research and biotechnology field and has to date written over 600 articles on the topic, interviewed over 100 of the leading researchers in the field, hosted livestream events focused on aging, as well as attending various medical industry conferences. His work has been featured in H+ magazine, Psychology Today, Singularity Weblog, Standpoint Magazine, Swiss Monthly, Keep me Prime, and New Economy Magazine. Steve is one of three recipients of the 2020 H+ Innovator Award and shares this honour with Mirko Ranieri โ€“ Google AR and Dinorah Delfin โ€“ Immortalists Magazine. The H+ Innovator Award looks into our community and acknowledges ideas and projects that encourage social change, achieve scientific accomplishments, technological advances, philosophical and intellectual visions, author unique narratives, build fascinating artistic ventures, and develop products that bridge gaps and help us to achieve transhumanist goals. Steve has a background in project management and administration which has helped him to build a united team for effective fundraising and content creation, while his additional knowledge of biology and statistical data analysis allows him to carefully assess and coordinate the scientific groups involved in the project.
  1. November 7, 2017

    What a great article. Immorality is possible!

    • November 8, 2017

      Immorality is always possible ;)

  2. November 8, 2017

    The claim that there must be a trend to either sluggish cells or cancer assumes that cell activity is driven only by internal processes in the cells and competition between cells. That ignores the possibility of extracellular forced reprogramming of cells. This can account for the age reversal in Turritopsis, which uses transdifferentiation of cells en masse.

  3. November 8, 2017

    I suspect that I might volunteer as an NS study subject. Travis

    Note : I tried to answer a “captcha” question (correctly) as 101 but she no work.

  4. Ariel Feinerman
    November 10, 2017

    Good article, although SENS is not about translating nature NS examples to human since it will involve much change of biochemistry (because NS species already NS, and need no repair medicine). SENS uses NS species merely as a proof. Also it is interesting how authors of the original paper deal with NS in their model. :3

  5. July 30, 2019

    “If you define it as living forever and being indestructible as in a comic book, then, no, it is highly unlikely.”

    Wait, hold on a second. Are you sure that indestructible (or almost indestructible) bionic bodies, designed to safely secure human brains forever, will always be highly unlikely? I’m not sure that that’s the case at all.

    • July 31, 2019

      Tom, even if this was true, and the odds are very much stacked against you, given the highly dangerous nature of the universe, the article is clearly talking about the near future and what is realistic for science to achieve in the next decade or so. Comic book, sci-fi, fantasy immortality is not a realistic proposition in the immediate future. Of course, do give me a call once the mecha crisis suits are available, I will take one in black please.

  6. August 1, 2019

    โ€œOne cannot apply such thinking when it comes to engineering negligible senescence in humans through the periodic repair of age-related damage.โ€

    Can you explain please in simple terms.

  7. sumitgautam0101
    May 28, 2020

    Great content, you just gained a new reader.

  8. alfred
    June 1, 2020

    This is a quot from a forum that was on the internet, starting in 1996. It expresses some of my ideas:

    Extra Terrestrial Migration – Gene Engineering
    Eternal Life Society
    Migrating to Infinite Space-Time.
    “We Can Become the Engineers of Our Own Body Chemistry.
    – In the Right Environment We Can Live Forever”

    Once we get off the finite surface of the planet earth and are capable of living in potentially infinite orbital space, there is no reason to have a finite lifespan.

    As engineers of our own body chemistry we can disable the genes that dictate the termination of our lifespan, as scientists have already demonstrated with plants and animals. There is no inherent limit to the “Lebensraum” (living space) in orbital space as there is on our planetary surface.

    The life span of each organism is determined by the environment to which it has adapted.

    The new environment will be our imagination which we can only fill if we live forever. We have to be immortal. There is no inherent limit to our imagination as long as there is time and space.

    The incentive to be a member in good standing in society is the pursuit of immortality. Humankind’s social activity, ultimately its urge to mate, is an instinct, just like the instinct to live. If the purpose of society is to protect and enhance the well being of its members, then providing the means to achieve immortality should be one of its highest priorities. The “New World” must provide individuals with access to the experts, the education and the means to achieve immortality.

    The difference between our present world based on the formation and protection of family, tribe, nation and the “New World” is that the latter must have as its goal the pursuit of individual immortality.

  9. Thom Kok
    April 2, 2021

    I would love to be alive as long as I want. Please make it happen!

  10. Neil
    April 2, 2021

    This was a really excellent article, Steve. I will be sure to share it. Thanks!

  11. Olatunji balogun Olatunji
    August 25, 2021

    I want to know more about this

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