Negligible senescence - Revision history

Andrea: /* Naked mole rat (Heterocephalus glaber) */

2023-02-24T20:57:33Z

Naked mole rat (Heterocephalus glaber)

← Older revision		Revision as of 20:57, 24 February 2023
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	Body composition is maintained from age 2 to age 24.		Body composition is maintained from age 2 to age 24.

			However, recent studies suggest that naked mole rats do age physiologically, and shown signs of decreased mobility or skin parchment, as well as epigenetic markers of aging.<ref>Kerepesi, C., Meer, M.V., Ablaeva, J. ''et al.'' Epigenetic aging of the demographically non-aging naked mole-rat. ''Nat Commun'' 13, 355 (2022). <nowiki>https://doi.org/10.1038/s41467-022-27959-9</nowiki></ref>

	Naked mole rats have low susceptibility to disease. Notably, neoplasm has not yet been observed in this species.		Naked mole rats have low susceptibility to disease. Notably, neoplasm has not yet been observed in this species.

Andrea: category change

2022-12-27T12:59:39Z

category change

← Older revision		Revision as of 12:59, 27 December 2022
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	Studies of negligibly senescent sea urchins, of various species and with a range of maximum life spans, have shown maintenance of:		Studies of negligibly senescent sea urchins, of various species and with a range of maximum life spans, have shown maintenance of:

	* telomeres;		* [[telomeres]];
	* antioxidant and proteasome enzyme activities;		* antioxidant and proteasome enzyme activities;
	* cellular pathways involved in energy metabolism, protein homeostasis and tissue regeneration		* cellular pathways involved in [[Metabolic flexibility\|energy metabolism]], [[Proteostasis\|protein homeostasis]] and tissue regeneration

	They have also shown a lack of major age-related accumulation of oxidative cellular damage.		They have also shown a lack of major age-related accumulation of oxidative cellular damage.
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	# '''Damage:''' As the toxins accumulate, they cause damage.		# '''Damage:''' As the toxins accumulate, they cause damage.
	# '''Pathology:''' The damage caused by the toxins drives age-related pathologies		# '''Pathology:''' The damage caused by the toxins drives age-related pathologies



	Negligible senescence could be engineered by interrupting one of these stages.		Negligible senescence could be engineered by interrupting one of these stages.

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	# Extracellular junk		# Extracellular junk
	# Tissue stiffening		# Tissue stiffening
	# Mitochondrial defects		# [[Mitochondrial dysfunction\|Mitochondrial defects]]

	Efforts to develop strategies for engineered negligible senescence therefore focus on methods for mitigating each of the above types of damage, using either existing biotechnology or plausible extensions of it.		Efforts to develop strategies for engineered negligible senescence therefore focus on methods for mitigating each of the above types of damage, using either existing biotechnology or plausible extensions of it.
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	* It might be necessary to eliminate retirement.		* It might be necessary to eliminate retirement.
	* There would be much greater pressure on the environment.		* There would be much greater pressure on the environment.



	<references />		<references />
	[[Category:Longevity]]		[[Category:Main list]]
			[[Category:Longevity concepts]]

Geroscientist: /* Strategies for engineered negligible senescence (SENS)[5] */

2021-12-14T10:38:54Z

Strategies for engineered negligible senescence (SENS)[5]

← Older revision		Revision as of 10:38, 14 December 2021
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	==== Naked mole rat (Heterocephalus glaber) ====<!-- Max Schulz: Negligible senescence is disputed in naked molde rats -->		==== Naked mole rat (Heterocephalus glaber) ====<!-- Max Schulz: Negligible senescence is disputed in naked molde rats -->

	The naked mole rat<ref>Buffenstein, R. (2008). Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species. ''Journal of Comparative Physiology B'', ''178''(4), 439-445.		The naked mole rat is the only mammal known to meet all three criteria of negligible senescence, thought it must be noted that some controversy still exists:<ref>Buffenstein, R. (2008). Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species. ''Journal of Comparative Physiology B'', ''178''(4), 439-445.
			</ref><ref>Ruby, J. G., Smith, M., & Buffenstein, R. (2018). Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age. ''elife'', ''7'', e31157.</ref><ref>Ruby, J. G., Smith, M., & Buffenstein, R. (2018). Naked mole-rat mortality rates defy Gompertzian laws by not increasing with age. ''elife'', ''7'', e31157.</ref>
	</ref> ~~is the only mammal known to meet all three criteria of negligible senescence:~~

	''1. No age-related increases in disease incidence and associated death rate:''		''1. No age-related increases in disease incidence and associated death rate:''
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	Body composition is maintained from age 2 to age 24.		Body composition is maintained from age 2 to age 24.

	Naked mole rats have low susceptibility to disease. Notably, neoplasm has ~~never~~ been observed in this species.		Naked mole rats have low susceptibility to disease. Notably, neoplasm has not yet been observed in this species.

	=== Aldabra giant tortoise ===		=== Aldabra giant tortoise ===

Schulzm: Added comment about naked mole rats

2021-10-19T09:49:18Z

Added comment about naked mole rats

← Older revision		Revision as of 09:49, 19 October 2021
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	== Examples of animals considered negligibly senescent ==		== Examples of animals considered negligibly senescent ==

	==== Naked mole rat (Heterocephalus glaber) ====		==== Naked mole rat (Heterocephalus glaber) ====<!-- Max Schulz: Negligible senescence is disputed in naked molde rats -->

	The naked mole rat<ref>Buffenstein, R. (2008). Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species. ''Journal of Comparative Physiology B'', ''178''(4), 439-445.		The naked mole rat<ref>Buffenstein, R. (2008). Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species. ''Journal of Comparative Physiology B'', ''178''(4), 439-445.

LM at 21:45, 12 August 2021

2021-08-12T21:45:16Z

← Older revision		Revision as of 21:45, 12 August 2021
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	==== Naked mole rat (Heterocephalus glaber) ====		==== Naked mole rat (Heterocephalus glaber) ====
	The naked mole rat is the only mammal known to meet all three criteria of negligible senescence:		The naked mole rat<ref>Buffenstein, R. (2008). Negligible senescence in the longest living rodent, the naked mole-rat: insights from a successfully aging species. ''Journal of Comparative Physiology B'', ''178''(4), 439-445.

			</ref> is the only mammal known to meet all three criteria of negligible senescence:

	''1. No age-related increases in disease incidence and associated death rate:''		''1. No age-related increases in disease incidence and associated death rate:''
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	=== Ocean quahog (Arctica islandica) ===		=== Ocean quahog (Arctica islandica) ===
	Bivalve molluscs provide the widest range of lifespans available for interspecies comparisons. The maximal lifespan in different populations of bivalve molluscs ranges from 36 for the Atlantic surfclam (Spisula solidissima) to >500 years for the ocean quahog (Arctica islandica), despite the similar size and living conditions. (Age is counted by growth rings on the shell). ~~<ref>Stenvinkel, P., & Shiels, P. G. (2019). Long-lived animals with negligible senescence: clues for ageing research. ''Biochemical Society Transactions'', ''47''(4), 1157-1164.</ref>~~		Bivalve molluscs <ref>Stenvinkel, P., & Shiels, P. G. (2019). Long-lived animals with negligible senescence: clues for ageing research. ''Biochemical Society Transactions'', ''47''(4), 1157-1164.</ref>provide the widest range of lifespans available for interspecies comparisons. The maximal lifespan in different populations of bivalve molluscs ranges from 36 for the Atlantic surfclam (Spisula solidissima) to >500 years for the ocean quahog (Arctica islandica), despite the similar size and living conditions. (Age is counted by growth rings on the shell).

	=== Sea urchin ===		=== Sea urchin ===
	Sea urchins<ref>Bodnar, A. G. (2015). Cellular and molecular mechanisms of negligible senescence: insight from the sea urchin. Invertebrate reproduction & development, 59(sup1), 23-27. </ref> are widely used as model organisms for scientific research~~. Part~~ of their value is their close phylogenetic relationship to humans.		Sea urchins<ref>Bodnar, A. G. (2015). Cellular and molecular mechanisms of negligible senescence: insight from the sea urchin. Invertebrate reproduction & development, 59(sup1), 23-27. </ref> are widely used as model organisms for scientific research, part of their value being their close phylogenetic relationship to humans.

			Sea urchins grow throughout their lives and can regenerate damaged appendages. Neoplasm is rare in these animals.

			Some species of sea urchins show negligible senescence, and among these species there is a wide variation in maximum life span, ranging from 4 years (Lytechinus variegatus) to 100 years (Strongylocentrotus franciscanus).

	~~Some~~ species ~~of sea urchins~~ show negligible senescence~~. Different species have considerably differing maximum life spans, ranging from 4 to 100 years. Comparison~~ between species with different maximum life spans provides a useful opportunity to investigate factors affecting both life span ~~and negligible senescence~~.		Comparison between sea urchin species that show negligible senescence and those that do not and between species with different maximum life spans provides a useful opportunity to investigate factors affecting both aging and life span.

	Studies of negligibly senescent sea urchins have shown maintenance of:		Studies of negligibly senescent sea urchins, of various species and with a range of maximum life spans, have shown maintenance of:

	* telomeres;		* telomeres;
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	They have also shown a lack of major age-related accumulation of oxidative cellular damage.		They have also shown a lack of major age-related accumulation of oxidative cellular damage.

	~~These findings were true of various sea urchin species with a range of maximum life spans.~~

	The findings suggest that negligible senescence relies on the maintenance of mechanisms that sustain tissue homeostasis and regenerative capacity.		The findings suggest that negligible senescence relies on the maintenance of mechanisms that sustain tissue homeostasis and regenerative capacity.

LM: Added section on sea urchins

2021-08-11T18:18:00Z

Added section on sea urchins

@@ Line 42: / Line 42: @@
 === Ocean quahog (Arctica islandica) ===
 Bivalve molluscs provide the widest range of lifespans available for interspecies comparisons. The maximal lifespan in different populations of bivalve molluscs ranges from 36 for the Atlantic surfclam (Spisula solidissima) to >500 years for the ocean quahog (Arctica islandica), despite the similar size and living conditions. (Age is counted by growth rings on the shell). <ref>Stenvinkel, P., & Shiels, P. G. (2019). Long-lived animals with negligible senescence: clues for ageing research. ''Biochemical Society Transactions'', ''47''(4), 1157-1164.</ref>
 == Strategies for engineered negligible senescence (SENS)<ref>Zealley, B., & De Grey, A. D. (2013). Strategies for engineered negligible senescence. Gerontology, 59(2), 183-189. </ref> ==
@@ Line 53: / Line 70: @@
 # '''Damage:''' As the toxins accumulate, they cause damage.
 # '''Pathology:''' The damage caused by the toxins drives age-related pathologies

LM at 20:35, 18 July 2021

2021-07-18T20:35:30Z

← Older revision		Revision as of 20:35, 18 July 2021
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	Negligible senescence refers to an absence of gradual deterioration with age, specifically an absence of:		Negligible senescence refers to an absence of gradual deterioration with age, specifically an absence of:

	~~(1)~~ age-related increases in disease incidence and associated death rate;		# age-related increases in disease incidence and associated death rate;
			# decrease in reproductive capability; and
	~~(2)~~ decrease in reproductive capability; and		# deterioration in physiological capacity, such as strength, mobility and sensory acuity.

	~~(3)~~ deterioration in physiological capacity, such as strength, mobility and sensory acuity.

	It should be noted that negligible senescence is not synonymous with immortality. An organism that displays negligible senescence - i.e. no gradual deterioration - can still die of a sudden process, whether internal or external, such as predator attack, accident, starvation, exposure to adverse environmental conditions, disease or semelparity.		It should be noted that negligible senescence is not synonymous with immortality. An organism that displays negligible senescence - i.e. no gradual deterioration - can still die of a sudden process, whether internal or external, such as predator attack, accident, starvation, exposure to adverse environmental conditions, disease or semelparity.
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	The naked mole rat is the only mammal known to meet all three criteria of negligible senescence:		The naked mole rat is the only mammal known to meet all three criteria of negligible senescence:

	''(1~~) no~~ age-related increases in disease incidence and associated death rate:''		''1. No age-related increases in disease incidence and associated death rate:''

	In the first two months of life babies are at increased risk of death from inadequate maternal care, cannibalism by siblings and poor inoculation of gastrointestinal flora and fauna. However, after this initial period the rate of death by natural causes is distributed randomly among all age groups rather than showing any age-related increase, except towards the end of the maximum species life span (i.e. the longest a member of the species has been observed to live), when there is believed to be a sudden increase in death rate.		In the first two months of life babies are at increased risk of death from inadequate maternal care, cannibalism by siblings and poor inoculation of gastrointestinal flora and fauna. However, after this initial period the rate of death by natural causes is distributed randomly among all age groups rather than showing any age-related increase, except towards the end of the maximum species life span (i.e. the longest a member of the species has been observed to live), when there is believed to be a sudden increase in death rate.

	''(2~~) no~~ decrease in reproductive capability:''		''2. No decrease in reproductive capability:''

	Breeding females show no menopause or decline in fertility, even after age 30. In fact, litter size tends to increase with age, although the pups born to older breeders are at greater risk of dying before weaning, possibly because of inadequate milk supply or because of greater disturbance to the larger colonies where these older breeders tend to be found.		Breeding females show no menopause or decline in fertility, even after age 30. In fact, litter size tends to increase with age, although the pups born to older breeders are at greater risk of dying before weaning, possibly because of inadequate milk supply or because of greater disturbance to the larger colonies where these older breeders tend to be found.
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	The long lifespan of breeding females casts doubt on most evolutionary theories of aging, which generally propose that there is a trade-off between fecundity and lifespan, as energy invested in reproduction is not invested in repairing and maintaining the body.		The long lifespan of breeding females casts doubt on most evolutionary theories of aging, which generally propose that there is a trade-off between fecundity and lifespan, as energy invested in reproduction is not invested in repairing and maintaining the body.

	(3) ''no deterioration in physiological capacity, such as strength, mobility and sensory acuity:''		3. ''No deterioration in physiological capacity, such as strength, mobility and sensory acuity:''

	Body composition is maintained from age 2 to age 24.		Body composition is maintained from age 2 to age 24.
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	# Tissue stiffening		# Tissue stiffening
	# Mitochondrial defects		# Mitochondrial defects


	Efforts to develop strategies for engineered negligible senescence therefore focus on methods for mitigating each of the above types of damage, using either existing biotechnology or plausible extensions of it.		Efforts to develop strategies for engineered negligible senescence therefore focus on methods for mitigating each of the above types of damage, using either existing biotechnology or plausible extensions of it.
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	# Compassionate motives: age-related deterioration has a negative impact on quality of life.		# Compassionate motives: age-related deterioration has a negative impact on quality of life.
			# Economic motives: resources have to be dedicated to supporting those suffering from age-related deterioration. The deterioration also compromises their ability to carry out productive work.
	# Economic motives: resources have to be dedicated to supporting those suffering from age-related deterioration. The deterioration also compromises their ability to carry out productive work.

	== Implications of deploying anti-senescence technologies widely ==		== Implications of deploying anti-senescence technologies widely ==

78.147.212.48: Added section "Strategies for engineered negligible senescence"

2021-07-18T18:18:42Z

Added section "Strategies for engineered negligible senescence"

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 Maximum observed lifespan: 205 years
-=== Lobsters ===
+=== Lobster ===
 Scientists do not currently have a way of establishing the age of lobsters with certainty, but it has been estimated<ref>https://cdnsciencepub.com/doi/abs/10.1139/f99-116</ref> that male European lobsters in the wild have an average life span of 31 years and a maximum  of 42 ± 5, while females have an average life span of 54 years and a maximum of 72 ± 9.
 === Lake sturgeon (Acipenser fulvescens) ===
 Maximum observed life span: 152 years
 == Implications of deploying anti-senescence technologies widely ==
@@ Line 56: / Line 97: @@
 * It might be necessary to eliminate retirement.
 * There would be much greater pressure on the environment.
 <references />
 [[Category:Longevity]]

Bogdan at 15:14, 5 July 2021

2021-07-05T15:14:31Z

← Older revision		Revision as of 15:14, 5 July 2021
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	* It might be necessary to eliminate retirement.		* It might be necessary to eliminate retirement.
	* There would be much greater pressure on the environment.		* There would be much greater pressure on the environment.
			<references />
			[[Category:Longevity]]

78.147.212.48: Posted first version of article

2021-07-04T21:08:54Z

Posted first version of article

New page

== Definition ==
Negligible senescence refers to an absence of gradual deterioration with age, specifically an absence of:

(1) age-related increases in disease incidence and associated death rate;

(2) decrease in reproductive capability; and

(3) deterioration in physiological capacity, such as strength, mobility and sensory acuity.

It should be noted that negligible senescence is not synonymous with immortality. An organism that displays negligible senescence - i.e. no gradual deterioration - can still die of a sudden process, whether internal or external, such as predator attack, accident, starvation, exposure to adverse environmental conditions, disease or semelparity.

== Examples of animals considered negligibly senescent ==

==== Naked mole rat (Heterocephalus glaber) ====
The naked mole rat is the only mammal known to meet all three criteria of negligible senescence:

''(1) no age-related increases in disease incidence and associated death rate:''

In the first two months of life babies are at increased risk of death from inadequate maternal care, cannibalism by siblings and poor inoculation of gastrointestinal flora and fauna. However, after this initial period the rate of death by natural causes is distributed randomly among all age groups rather than showing any age-related increase, except towards the end of the maximum species life span (i.e. the longest a member of the species has been observed to live), when there is believed to be a sudden increase in death rate.

''(2) no decrease in reproductive capability:''

Breeding females show no menopause or decline in fertility, even after age 30. In fact, litter size tends to increase with age, although the pups born to older breeders are at greater risk of dying before weaning, possibly because of inadequate milk supply or because of greater disturbance to the larger colonies where these older breeders tend to be found.

The long lifespan of breeding females casts doubt on most evolutionary theories of aging, which generally propose that there is a trade-off between fecundity and lifespan, as energy invested in reproduction is not invested in repairing and maintaining the body.

(3) ''no deterioration in physiological capacity, such as strength, mobility and sensory acuity:''

Body composition is maintained from age 2 to age 24.

Naked mole rats have low susceptibility to disease. Notably, neoplasm has never been observed in this species.

=== Aldabra giant tortoise ===
Maximum observed life span: 255 years

=== Rougheye rockfish (Sebastes aleutianus) ===
Maximum observed lifespan: 205 years

=== Lobsters ===
Scientists do not currently have a way of establishing the age of lobsters with certainty, but it has been estimated<ref>https://cdnsciencepub.com/doi/abs/10.1139/f99-116</ref> that male European lobsters in the wild have an average life span of 31 years and a maximum of 42 ± 5, while females have an average life span of 54 years and a maximum of 72 ± 9.

=== Lake sturgeon (Acipenser fulvescens) ===
Maximum observed life span: 152 years

== Implications of deploying anti-senescence technologies widely ==
Widespread deployment of anti-senescence technologies would cause populations to surge. <ref><nowiki>https://www.sciencedirect.com/science/article/pii/S0040162515001985</nowiki> </ref>

==== Advantages ====

* The labor force would be larger and, on average, healthier, which would boost economic growth.

==== Disadvantages ====

* The cost of implementing the anti-senescence technologies could still outweigh the resulting economic growth in some countries.
* In order to finance citizens’ longer lives, governments would have to restructure their financing.
* It might be necessary to eliminate retirement.
* There would be much greater pressure on the environment.