The Longevity of Tyrannosaurs
Sometimes I point out research not because it is relevant to the immediate cause of building therapies to control aging, but because it is interesting. That is definitely the case here: I doubt you can find a practical use for a paper on the modeling of aging and longevity in tyrannosaurs. That doesn't stop it from being a fascinating topic, of course.
Researchers follow their interests, and that is worth celebrating. If no-one was interested in deciphering and more importantly treating aging, we would still be in exactly the same position as all of our ancestors: doomed to short lives terminated by a period of pain, suffering, and debility. As things stand we are only maybe doomed, with the odds strongly depending on date of birth and progress in raising funding for research, but even that is an enormous improvement. Whether or not you and I personally make it into the age of radical life extension, by bootstrapping the use of one therapy at a time to incrementally repair our biochemistry and extend healthy life, it remains the case that by supporting this cause we help to create the means to save countless lives in the near future.
Aging is near universal trait among species, and has been for a very long time, all the way back to the murky origins of cellular life. You might look on the universality of aging as the result of an evolutionary race to the bottom, similar in a way to the human relationship with organized violence. War hurts the individual and diverts efforts from productive use, but the only way to survive as a collective when your competitors are proficient at violence is to follow the same path - and so everyone diverts resources into mutual destruction rather than growth. Aging may be such an effective evolutionary strategy because it enables better survival of a species in the face of environmental change. We age because the world changes, and ancestral species with aging replaced near all species without aging, right from the outset. Only in a few scattered niches do we find a tiny number of species where evolution has led to a move away from aging as a strategy. Thus when we look into the deep past and model the lives of species such as dinosaurs, those for which enough bones exist for decent models of life span, we should not be at all surprised to find the same patterns of aging as we see today.
Tyrannosaurs as long-lived species
Tyrannosaurs including Tyrannosaurus rex (shortly T. rex meaning tyrant lizard king) are very popular to the public as well as among paleontologists although they became extinct 66 million years ago. Many mysteries about population ecology and actual behavior of tyrannosaurs have been resolved thanks to modern technologies and collective data in paleobiology. In particular, rigorous anatomic methods have been developed and eventually reliable life tables for tyrannosaurs were estimated. Using their demographic data, tyrannosaur aging dynamics was carefully interpreted. Gompertz function or Weibull function was utilized to quantify tyrannosaur survival curves, but both might be insufficient to appropriately describe complicated biological survival curves. Suitable mathematical descriptions and statistical methods are still required to quantify survival and mortality curves of tyrannosaurs.Here we address a methodology that enables us to appropriately quantify tyrannosaur survival and mortality curves by utilizing modified stretched exponential survival functions, which we have developed to precisely quantify human demographics. We find a demographic analogy between tyrannosaurs and 18th-century humans despite scale and ecological differences. Interestingly, mortality patterns for tyrannosaurs resemble those for 18th-century humans: probably tyrannosaurs would be able to live so long to undergo aging before maximum lifespans, while their longevity strategy would be more alike to big birds rather than 18th-century humans. We attribute longevity of tyrannosaurs to late sexual maturity, large body size, and rapid growth rate, which would be favorable for longevity.
Analyzing the stretched exponents helps evaluation of longevity strategy across species. Although survival and mortality curves look very similar between tyrannosaurs and 18th-century humans, their stretched exponent patterns are significantly different. The stretched exponents with respect to the normalized age show a clear difference in longevity strategy between 18th-century humans and tyrannosaurs. For 18th-century humans, the curves are similar to those of apes or crocodilians, whereas those of Albertosaurus sarcophagus show similar patterns with deer, cassoway, or raptors. This analysis suggests that tyrannosaurs would live longer than other species in terms of the normalized age. Tyrannosaurs would exhibit late sexual maturity, large body size, and rapid growth rate, which would be favorable for longevity. There would be benefits from predation relief by rapid growth for longevity of tyrannosaurs. Probably becoming giants through rapid growth or becoming apex predators would be favorable to acquire exceptional benefits for releases from predation in early life, which would be good for longevity, regardless of uncertainty on whether they were primarily predators or scavengers.
I think the most interesting aspect of this species' life cycle (if I interpreted the article's analysis correctly) is that its members aged fairly rapidly vis-a-vis many other species. In other words, these creatures' life cycles exhibited a very compressed period between sexual maturity and old age. I wonder why...
@Anthony Hopper
Hi Anthony ! Just my 2 cents, I believe
it could be explained by factors affecting the evolutionary specie's survival strategies.
It grows to this large (reptile-evolving-to-feathered-flying-bird/turkey/chicken-in-the-making) animal
because, like humans, it is has neotenous (neoteny) features of late puberty and retains juvenility until adulthood.
In the article, T-rex reach adulthood puberty very late at 18 years old and die before/at MLSP 28 years old.
This super short compressed 10 years of post-reproduction lifespan can be explained by neuroendocrinology, neuroplasticity,
brain size/mass (T-rex brain not so big proportionnaly) affecting important elements like the IGF-1 axis, which
controls longevity, lifespan, reproduction, growth, size, mass, morphology and predation. Neuroendrocrinal signals, via production
of sexual hormones, control the survival strategy and careful balance between resource allocation towards increased sexual reproduction
to improve specie survival vs longevity gene resource allocation/expenditure transfer. Brain IGF-1Rs (Insuline Growth Factor-1 Receptor) catalyze this whole growth vs longevity vs mass vs metabolism vs reproduction vs oxidative stress, by the neuroendocrine signals that created by GH (Growth Hormones) and sexual hormones (pituitary, pineal, testosterone and estrogen, LH, FSH, SHBG, etc) acting on brain neuron IGF-1 receptors.
Being an apex carnivorous predator, with little to no competition and a muscular body/huge pointy teeth/huge size, meant that slow
growth/late puberty allowed the animal to reach the gigantic size it was as an adult (and that size at adolescence was already 'big' enough to push competitors away and so T-rex could defend itself quick enough without needing mother T-rex to help out); once adult, reproduction was tantamount, female adult T-rex layed up to 21 eggs in one pregnancy; this would have been highly costly sexual resources wise, reducing the allocated amount of resources
for post-reproduction specie longevity. Plus, Testosterone levels were high, testosterones increases muscle mass, total mass, size and predatorial competitive behavior.
Being predators, they predated on the prey (since they were 'Big'/being Big is a (very big, no pun) predatorial advantage), hormones were in play for that effect. Males show higher testosterone *at the cost of a reduced lifespan/longevity* (testosterone increases ROS production and oxidative stress 'by Fight or Flight mechanism (Cannon)' in concert with increased adreno-corticoid/somatotrophic/adrenal gland axis production of adrenaline/cortisol levels) during highly stressful situations such as conflict and predation gives.
Testosterone increases the males reproduction capacity in his testis and spermatogenesis (a cost of increased sexual resources for fertility/offspring output by multiple females); and also, by combative predatorial violent behavior to competitors (Alpha-Male), female obtention for reproduction.
This mosty likely altered their antioxidative mechanisms (brain IGF-1R alters redox chemistry) and thus, would make them age faster -post-reproduction.
Evolution chose them (for extinction) for a good enough life (30 years) but that once they reproduced, it was game over; they aged triply faster after reproduction (a state of diabetes/accelerated aging in a sense); yielding
post-reproduction lifespan compression. Anyway, that's how I see it : ), I could be totally off; but it really is a body growth thing.
1. http://www.impactaging.com/papers/v5/n4/full/100552.html
2. https://www.theguardian.com/science/blog/2014/mar/04/long-healthy-life-fertility-igf-longevity
3. http://www.ncbi.nlm.nih.gov/pubmed/20736031
4. http://www.ncbi.nlm.nih.gov/pubmed/23873963
5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2439518/
6. http://www.ncbi.nlm.nih.gov/pubmed/22729283
7. http://www.ncbi.nlm.nih.gov/pubmed/7486812
8. http://www.ncbi.nlm.nih.gov/pubmed/7690364
9. https://www.researchgate.net/publication/40660993_Body_Mass_Estimates_in_Extinct_Mammals_from_Limb_Bone_Dimensions_the_Case_of_North_American_Hyaenodontids
Mostly off-topic, and without looking, may I request a detailed post of the most inexpensive senescence fighting strategies, supplements, and tips - including calorie restriction? There's probably many crowd-sourced pages with a wealth of excellent information. I apologize in advance for any frustration this post may cause.
Corwin, you are a newcomer to this site, it isn't? ;)
https://www.fightaging.org/archives/2006/12/magical-thinking-abounds-in-the-antiaging-marketplace.php
@Corwin: Calorie restriction and regular moderate exercise are the best of the cheap options for improving health and extending healthy longevity by some small amount in humans. I'm sure that you can find resources on recommended exercise programs. For calorie restriction, you might start here:
https://www.fightaging.org/archives/2002/11/calorie-restriction-explained.php
Or take a look at the resources provided by the Calorie Restriction Society.
http://www.crsociety.org/
Supplements are a great way to waste money and time. There is no proven benefit by going beyond meeting RDAs, such as by taking a simple multivitamin, and the consensus in the scientific community is that some supplements are probably marginally harmful. See:
https://encrypted.google.com/search?q=site%3Afightaging.org+myth%20supplements
Of course the people that sell supplements are happy to tell you otherwise.
You must realize that exercise and calorie restriction are simply taking good care of health. They don't significantly change the outcome in humans, which is that you die on the same schedule as your grandparents. To change that we need to support research and development. You should read the introduction and the FAQ:
https://www.fightaging.org/introduction/
https://www.fightaging.org/faq/
In reference to Corwin's comment
It would be really nice if there was a website or section of this site that had a list of types of aging damage or list of the top ten diseases which cause death and the top 3 currently available ways (medicines, supplements, nutrients, or anti-aging therapies) that attenuate the increase of it (aging damage) or decrease the mortality rate from it (disease). Of course with links to the studies which support the ones chosen. Personally this is how I organize longevity information mentally.
I was shocked that on reddit in r/longevity there were multiple people who had been reading and commenting on r/longevity for some time and then when someone new asked for information on what they should do to extend their lifespan they basically said there wasn't anything except eat healthy, exercise, and donate to SENS. It's almost heartbreakingly sad that the information and studies are available to them on how to increase the probability of them living longer and they don't read it or don't seem to understand it.
Santi, the reply is simple: there are currently no therapies that eliminate or decrease the main damages that cause aging. The best you can do to extend your life is to donate to SENS research and sign a cryonics contract.
@Antonio
Putting aside the discussion on which theory of aging is correct, there are a multitude of ways you can increase the probability that you will live longer. Current scientific studies use mortality risk reduction instead of expected lifespan extention. However if you want to you can learn how to take a mortality risk reduction at a certain age and calculate the expected lifespan extention.
The leading causes of death in the US are heart disease & stroke, cancer, diabetes, influenza & pneumonia, chronic respiratory disease, Alzheimer's, diabetes, and accidents.
I will start with the most obvious case and continue from there to show my point. Can you reduce your risk of dieing by accidents? Yes obviously. If you always wear your seat belt while in the front seat it reduces the risk of death by vehicle accident by 45%. There are of course a many ways to reduce risk of death by vehicle accident, going to he most extreme if you live in a small city outside the US that doesn't have or allow vehicles your risk goes to zero. If someone doesn't die of a vehicle accident they will die at a later age which increases the average life expectancy.
Cancer is the second leading cause of death in the US and in many parts of the US the leading cause. Can you reduce your risk of dieing by cancer. Yes obviously. Are 70%+ cases of cancer cancer due to modifiable lifestyle factors like a recent study said or something less, I don't know. However I do know there are many ways to reduce risk of death by cancer. The most obvious being skin cancer. Everyone knows how to reduce their risk of skin cancer. Using SPF 50 decreases the rate of melanoma by around 50% for the same amount of time in the sun. Did you know the sun continues to damage your dna hours after you stop being in the sun due to a chemical reaction/energy transfer but you can decrease that skin/dna damage by stopping the chemical reaction. What about lung cancer. Yes obviously lifestyle choices are a very large part of the risk of lung cancer. How about colon cancer, yes we know how to reduce the risk of colon cancer by food choices and medical screening, prostate cancer yep we know how to reduce risk of prostate cancer, breast cancer yes, throat cancer, yes cervical cancer, yes, you get the idea.
Risk of death by cardiovascular disease. Yes of course we know how to reduce risk of death by cardiovascular disease. Due to AGEs and other reasons blood pressure rises normally with age. The difference between an average blood pressure of 120/80 and 130/90 is a 25% increase in having a cardiovascular event within the next 10 years. Can you lower blood pressure yes can you lower bad cholesterol yes can you decrease the rate of AGEs yes.
Diabetes - can you take a medicine and decrease your risk of developing diabetes without changing food choices yes. From he studies I have read it looks like you can cut the risk in half from medicine alone. Can you reduce the damage done to your body if you already have diabetes? Yes obviously, the whole discussion on metformin stems from this as normally diabetics die 8 years earlier but with metformin they live longer than non-diabetics.
Alzheimer's - in a recent study 2/3rds of cases were estimated to be preventable by altering 6 modifiable factors.
What about influenza & pneumonia? Can we improve the immune system or decrease the rate of aging in the thymus. Yes it seems like recent news shows we can.
I could go on and on but you get the idea. Any decrease in mortality risk increases the average lifespan by some amount. You may not think it is worth the time but what if you add up all these decreases in mortality risk and on average decrease your risk of all the top causes of death by 40%? Will you make it to 100? Will you make it to the LEV? You have just now increased your chances
@Santi: You were asking for something that reduces aging damage. Nothing of your last post reduces aging damage.
See this graph: http://s8.postimg.org/chq66z1yb/esperanza.png
See how the lines become horizontal for older people. We haven't developed any treatment for aging yet.
@Antonio
I said "attenuate (reduce) the rate aging damage" or "decrease mortality rate" and my shock to people in the longevity movement saying there currently wasn't any way to "extend lifespan."
I only use the words "aging damage" to try and be inclusive to the SENS followers. If that is confusing I will stop using it and only say "ways to extend lifespan." Really it doesn't matter what you call it the only thing that matters is lifespan extention be that from reducing AGEs or telomerase extention or slowing epigenetic drift. From my post it is obvious that we can decrease mortality risk with current technology which means that we can extend a person's lifespan who does those things. However, I understand very few people will utilize all the knowledge found on fightaging.org to extend their lifespan and die in similar patterns to your chart. I try and do my part by continually trying to smash that idea that lifespan can't be extended with current technology so more people can live longer. You can tell me if you changed your mind after the discussion.
Your link is average lifespan which is good for discussion on history but isn't very relevant to a discussion on lifespan extention with current technology since it is on the average person. As I said the average person doesn't use the latest in lifespan extention knowledge. In addition even if everyone did, lifespan extention strategies have changed dramatically in the last 50 years, so much so that it isn't even comparable. This means as lifespan is such a long time the only way that we can compare lifespan extention strategies is looking at reductions in 5 to 10 year mortality rates. For example the death rate among American centenarians has dropped 14% percent for women and 20% for men from 2008 to 2014. 20% drop in a 6 year period, I bet someone who follows lifespan extention strategies would be even higher with the new information on how to stop Alzheimer's and remove misfolded proteins. Centenarians will keep dieing rapidly though until senile systemic amyloidosis is dealt with as that is what kills the majority of the extremely old.
BTW we have known for many years how to attenuate the rate of AGEs. Meaning yes we know how to reduce the rate of a type of aging damage that SENS has listed. Also we now know of a way to decrease senescent cells another type of aging damage listed by SENS.
Correct me if I am wrong about senescent cells and AGEs being considered aging damage by SENS as I don't follow them closely.
@Santi
@Santi
Hi Santi !
I believe what is being infered is that average people (but who are not careless of their aging and try to do something about it) can do some of the preventative actions you mentioned. It's just many of these actions are extrinsic in effect and intrinsic aging continues its course despite taking these actions. It can be slowed modestly by them (such as CR, nutrient changes, antioxidants, senolytics, stem cell injection, hTERT activation, vitamins, not smoking, nor drinking, doing exercise, learning, having positive social interactions, sleeping monotonic same 7 hours to keep monotonic circadian clock rhythms and doing destressing relaxing meditation/yoga), it's just they make for an increase in average lifespan and healthspan. Not much for Maximum lifespan increase.
Meaning you could do all those things and die at 99 - but no that later than ~122.
SENS therapies, the combined 7 could makes us go above MLSP, possibly up to 350 or 4-digits like De Grey said, because their repair the major damages to a level no therapy can right now.
But, I will give it to you, I have faith but I feel that, like other companies tried, may end up therapeutic in goal, by force. On paper, 'it works', these biorejuvenation therapies I mean; in practice, it may end up failing initial goal of extreme lifespan extension and become health therapies improving chances to be centenarian, no more.
@Santi: Well, you can "extend your lifespan" by non smoking, but that has nothing to do with aging. Again, there is no current therapy that has proven to do something to the aging process in humans.