Teloyears.com. I got my telomere length measured and found it quite interesting and useful.
Telomere shortening rate predicts species life span
31–40 of 63 posts
Re: Telomere shortening rate predicts species life span
#32this makes me think that telomeres are not the main cause of aging-related death. My mental model is: if you run out of telomere before you get old, you start to get disease - and that’s maladaptive. So there’s evolutionary pressure to slow down your shortening rate, up to a point. Once it becomes unlikely that you’ll outlive your telomeres, there’s no more pressure. So your telomere length + rate becomes a measureme…
This doesn't really make sense does it? There's only really evolutionary pressure up to the end of your child rearing years, no?
Humans are double-viviparous species, meaning average grandparent lives past its grandchild's puberty. Humans are also atricial. These traits are shared by elephants, whales and dolphins too. However, humans are the only animal species those are triple-viviparous in occasions, meaning great-grandparent lives past its great-grandchild's puberty.
Re: Telomere shortening rate predicts species life span
#33Re: Telomere shortening rate predicts species life span
#34Earlier quoted context omitted.
This doesn't really make sense does it? There's only really evolutionary pressure up to the end of your child rearing years, no?
Should be context dependent. New parents benefit a lot from their own elder family members giving them advice on the basics; in an environment with less information (i.e. no internet), the advantage vs. people with no parents or family to help would have been substantial. So unless we expand the definition of “child-rearing years”, I think it could go either way.
for any amount of food, it's better to have an adult rather than an elder, for any particular gene.
So a truly optimal age system would have no old age at all, you will just die off after your children are self-sustaining.
Re: Telomere shortening rate predicts species life span
#35Earlier quoted context omitted.
It's true, and the microscopic theory was done by the same physicist who found the macroscopic relationship, Geoffrey West (one of my personal heroes an current director of the Santa Fe Institute). The theory also explains the upper and lower bounds for the possible size of an animal. If you want to read about it he wrote an amazing book called Scale. I _highly_ recommend it.
OK, I'll add a bit to my previous comment. Is there a limit to how small a mammal can be? If so, what sets the scale? TL;DR – effective pumping of blood requires precise allowable branching network of capillaries in the circulatory system. At a certain size this network goes from AC to DC and sets the scale for metabolic rate and lifespan in all animals with a circulatory system. The scale is set by impendance matchi…
How are early capillary branches (think of liver network in mammals) and metabolic rate irregularities accounted in this scheme (e.g. average human lives thrice as long and has a metabolism which works twice as fast as in an animal of comparable size)?
Re: Telomere shortening rate predicts species life span
#36Hasn't this been known for a while now? I swear I learned about this in AP Bio a decade ago.
It was on TV about 2 years ago or so.
Re: Telomere shortening rate predicts species life span
#37this makes me think that telomeres are not the main cause of aging-related death. My mental model is: if you run out of telomere before you get old, you start to get disease - and that’s maladaptive. So there’s evolutionary pressure to slow down your shortening rate, up to a point. Once it becomes unlikely that you’ll outlive your telomeres, there’s no more pressure. So your telomere length + rate becomes a measureme…
> this makes me think that telomeres are not the main cause of aging-related death
That's an interesting argument, but couldn't you use the same reasoning to argue that telomeres are the main cause of aging-related death? The mental model I'm thinking is: As you run out of telomeres, you get diseases and you can't reproduce - and that’s maladaptive. So there’s evolutionary pressure to slow down the shortening rate, up to the point where you have children (plus grandchildren in the case of humans). When you're living long enough to have one or two generations of offspring, there’s no more pressure to correct the telomere problem.
Wouldn't your argument and mine be equally consistent with the featured article (that shortening rate predicts life span)?
Re: Telomere shortening rate predicts species life span
#38Earlier quoted context omitted.
This doesn't really make sense does it? There's only really evolutionary pressure up to the end of your child rearing years, no?
Humans are double-viviparous species, meaning average grandparent lives past its grandchild's puberty. Humans are also atricial. These traits are shared by elephants, whales and dolphins too. However, humans are the only animal species those are triple-viviparous in occasions, meaning great-grandparent lives past its great-grandchild's puberty.
Human's average lifespans have been a lot shorter throughout history.
Re: Telomere shortening rate predicts species life span
#39I had read somewhere that telomere length reduces each time a cell divides. Assuming that, telomere shortening rate is directly indicative of the number of times cells have gone through division. Could that not mean that telomere shortening rate is just estimating cell division rates and the latter relate to life span for an entirely different reason? Is this or some other study show that shortening rate is a better predictor of life span than cell division rate?
Re: Telomere shortening rate predicts species life span
#40Earlier quoted context omitted.
That's the assumption, but I have never seen or done the math either, which is ridiculous because it shouldn't take more than 5 minutes to get some estimates.
Okay, you shamed me into doing it :) So, this is really rough napkin math, but here goes: Assuming that... ... a sedentary person (Donald) has a resting BPM of 80. ... an active runner (Justin) has a resting BPM of 60, and a peak BPM of 180 (while running) If Justin runs for a solid 2 hours, five times a week, he will have 158*60*60 + 10*60*180 = 676,800 beats per week While Donald, who doesn't run, but averages 1 ho…
Thanks for doing the math. I’d say 130-140 would be better than 180 for someone in shape.
Most people can’t even hit 180 after their 20s.