[math-fun] Immortality and mortality
As previously discussed, humans exhibit an exponential(time) death-rate curve, Gompertz law, which is really bad news for those who'd like to live. Furthermore, it looks like there are no remarkably long-lived mammals. The longest lived besides humans are (?) elephants, the oldest known elephant lived to age 86 in Taipei zoo. If we ask for animals that lived longer than the human record of 122 years, the only known advanced animals that clearly do that are several varieties of tortoises, which can live at least 250 years in some cases. And there are a few other birds and reptiles which might be able to exceed 122 years although it has never been observed to happen. Humans might be able to live longer via genetic engineering, more precisely genetic "theft," from a few of those long-lived animals. DNA sequencing could shed light. E.g. elephants were just sequenced and found to have about 50 copies of the p53 tumor-suppressor gene (humans have only 1 copy) which perhaps explains why elephants get cancer much less than humans do. Some primitive lifeforms can, however, entirely avoid Gompertz law -- which could be regarded as immortality, at least by comparison to us -- at least as far as anybody has been able to tell, their DeathRate(age) curves are asymptotically constant. These include "hydra." So perhaps Gompertz law only happens to "complex" animals, not to "simple" ones. Biochemically speaking, of course even hydra is a extremely complex object, but, e.g. it has few or no "organs" so perhaps the problem is the cell differentiation and macroscopic-development processes that happen in advanced animals, which perhaps are entirely absent in hydra. The mathematical question is: what really is the underlying cause of Gompertz law? Which as far as I know, was never really understood. -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)
http://www.mnn.com/earth-matters/animals/stories/10-animals-that-live-the-lo... On Thu, Oct 15, 2015 at 9:22 AM, Warren D Smith <warren.wds@gmail.com> wrote:
As previously discussed, humans exhibit an exponential(time) death-rate curve, Gompertz law, which is really bad news for those who'd like to live.
Furthermore, it looks like there are no remarkably long-lived mammals. The longest lived besides humans are (?) elephants, the oldest known elephant lived to age 86 in Taipei zoo.
If we ask for animals that lived longer than the human record of 122 years, the only known advanced animals that clearly do that are several varieties of tortoises, which can live at least 250 years in some cases. And there are a few other birds and reptiles which might be able to exceed 122 years although it has never been observed to happen.
Humans might be able to live longer via genetic engineering, more precisely genetic "theft," from a few of those long-lived animals. DNA sequencing could shed light. E.g. elephants were just sequenced and found to have about 50 copies of the p53 tumor-suppressor gene (humans have only 1 copy) which perhaps explains why elephants get cancer much less than humans do.
Some primitive lifeforms can, however, entirely avoid Gompertz law -- which could be regarded as immortality, at least by comparison to us -- at least as far as anybody has been able to tell, their DeathRate(age) curves are asymptotically constant. These include "hydra."
So perhaps Gompertz law only happens to "complex" animals, not to "simple" ones. Biochemically speaking, of course even hydra is a extremely complex object, but, e.g. it has few or no "organs" so perhaps the problem is the cell differentiation and macroscopic-development processes that happen in advanced animals, which perhaps are entirely absent in hydra. The mathematical question is: what really is the underlying cause of Gompertz law?
Which as far as I know, was never really understood.
-- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)
_______________________________________________ math-fun mailing list math-fun@mailman.xmission.com https://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
-- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com
http://www.mnn.com/earth-matters/animals/stories/10-animals-that-live-the-lo... about long-lived animals was interesting but I warn you its author appears to have been careless and should not be trusted without independent checking. Still, I'd forgot about whales as mammals, and it does appear bowhead whales can have long lifespans, at least 115 years and perhaps as long as 250. The largest animals (whales, elephants) have more darwinian motivation to develop better anti-cancer genes, so it makes sense too. "The bowhead had unique mutations in two genes linked to lifespan in animals... the ERCC1 gene, which is believed to repair DNA, increase cancer resistance and slow aging, and the PCNA gene, which is also linked to DNA repair... Magalhaes is now seeking funding for a project that will insert the whales’ genes into mice to see if that improves..." -- Warren D. Smith http://RangeVoting.org <-- add your endorsement (by clicking "endorse" as 1st step)
participants (2)
-
Mike Stay -
Warren D Smith