Longevity and ftness

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Longevity and ftness

Postby wolfhnd on July 29th, 2017, 6:09 pm 

Biowizard

I know you have an interest in aging. In another thread we are discussing why animals live past the age where they are fertile. My guess is that it is related to the need to slow aging in species that have extended pregnancy and infant care. If it takes a number of years to raise offspring to semi independence longer life spans may be advantageous. That would however not explain long life spans in species such as parrots. In some species longer life spans may result from low birthrates and high infant mortality. The two concepts are of course not mutually exclusive.

Your thoughts please.
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Re: Longevity and ftness

Postby doogles on July 30th, 2017, 4:00 am 

wolfhnd wrote:Biowizard

I know you have an interest in aging. In another thread we are discussing why animals live past the age where they are fertile. My guess is that it is related to the need to slow aging in species that have extended pregnancy and infant care. If it takes a number of years to raise offspring to semi independence longer life spans may be advantageous. That would however not explain long life spans in species such as parrots. In some species longer life spans may result from low birthrates and high infant mortality. The two concepts are of course not mutually exclusive.

Your thoughts please.


wolfhnd, I’m not sure whether you wished for anyone else but Biowizard to join in this thread, but following your OP, I would like to add to your list of animals that live to ripe old ages.

This reference relates to tortoises - https://www.google.com.au/#q=galapagos+ ... 1398571044“Harriet (c. 1830 – 23 June 2006) was a Galápagos tortoise (Geochelone nigra porteri) who had an estimated age of 175 years at the time of her death in Australia. Harriet is the third oldest tortoise, behind Tu'i Malila, who died in 1965 at the age of 188, and Adwaita, who died in 2006 at the estimated age of 255.”

And this relates to multiple species - https://www.sciencealert.com/is-this-bi ... -the-world - “Make some room tortoises and whales, because it looks like tubeworms have the real secret to longevity. A new study has found that these deep-sea animals from the Gulf of Mexico can live to be between 100 and 300 years old.
At more than 250 years old, Escarpia laminata achieves a lifespan that exceeds other longevity records," says lead researcher Alanna Durkin from Temple University in the US.
Here on land, the longest-living vertebrate is the Galapagos giant tortoise (Chelonoidis nigra) with one example pegged at 177 years old. When it comes to mammals, the Bowhead whale (Balaena mysticetus) takes the top place for longevity at 211 years old.
But if you really want to live a long life, the deep sea is the place to be for living at a slower pace. Here you will find black corals (Antipatharia) that are more than 4,000 years old, and rockfish that can live up to 205 years.
There's even an octopus (Graneledone boreopacifica) that holds the record for the longest ever egg-brooding time at a staggering 53 months.
And let's not forget Ming the clam, an ocean quahog (Arctica islandica) that lived until the grand old age of 507 years. … “


If we researched ALL of the known evidence relating to the longevity of species on land and sea, and in the air, we just may come up with some relevant properties associated with long-lived species.

For example from the above limited data, one just may get the impression that living in the ocean MAY be relevant. This just MAY suggest that sea animals live longer on average than land animals (perhaps a gravity effect?).

But there is not yet enough data across all species to draw conclusions. Interesting topic Wolfhnd.
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Re: Longevity and ftness

Postby wolfhnd on July 30th, 2017, 5:38 am 

doogles » Sun Jul 30, 2017 8:00 am wrote:
wolfhnd wrote:Biowizard

I know you have an interest in aging. In another thread we are discussing why animals live past the age where they are fertile. My guess is that it is related to the need to slow aging in species that have extended pregnancy and infant care. If it takes a number of years to raise offspring to semi independence longer life spans may be advantageous. That would however not explain long life spans in species such as parrots. In some species longer life spans may result from low birthrates and high infant mortality. The two concepts are of course not mutually exclusive.

Your thoughts please.


wolfhnd, I’m not sure whether you wished for anyone else but Biowizard to join in this thread, but following your OP, I would like to add to your list of animals that live to ripe old ages.

This reference relates to tortoises - https://www.google.com.au/#q=galapagos+ ... 1398571044“Harriet (c. 1830 – 23 June 2006) was a Galápagos tortoise (Geochelone nigra porteri) who had an estimated age of 175 years at the time of her death in Australia. Harriet is the third oldest tortoise, behind Tu'i Malila, who died in 1965 at the age of 188, and Adwaita, who died in 2006 at the estimated age of 255.”

And this relates to multiple species - https://www.sciencealert.com/is-this-bi ... -the-world - “Make some room tortoises and whales, because it looks like tubeworms have the real secret to longevity. A new study has found that these deep-sea animals from the Gulf of Mexico can live to be between 100 and 300 years old.
At more than 250 years old, Escarpia laminata achieves a lifespan that exceeds other longevity records," says lead researcher Alanna Durkin from Temple University in the US.
Here on land, the longest-living vertebrate is the Galapagos giant tortoise (Chelonoidis nigra) with one example pegged at 177 years old. When it comes to mammals, the Bowhead whale (Balaena mysticetus) takes the top place for longevity at 211 years old.
But if you really want to live a long life, the deep sea is the place to be for living at a slower pace. Here you will find black corals (Antipatharia) that are more than 4,000 years old, and rockfish that can live up to 205 years.
There's even an octopus (Graneledone boreopacifica) that holds the record for the longest ever egg-brooding time at a staggering 53 months.
And let's not forget Ming the clam, an ocean quahog (Arctica islandica) that lived until the grand old age of 507 years. … “


If we researched ALL of the known evidence relating to the longevity of species on land and sea, and in the air, we just may come up with some relevant properties associated with long-lived species.

For example from the above limited data, one just may get the impression that living in the ocean MAY be relevant. This just MAY suggest that sea animals live longer on average than land animals (perhaps a gravity effect?).

But there is not yet enough data across all species to draw conclusions. Interesting topic Wolfhnd.


Thanks for responding doogles. I asked Bio because I don't get much participation in my threads so I thought a request with a please might be appropriate.

The reason I asked is because I'm researching menopause and it seemed like a good idea to figure out why different species have different life expectancy before asking why some species live past fertility. I have selected elephants and killer whales to compare to humans. Female Elephants remain fertile throughout their life expectancy while killer whales do not. Elephants born to older females have a higher survival rate while older whales have a lower success rate at raising their babies. Both killer whales and elephants live in matriarchal societies. While it may not be obvious humans are also matriarchal from a genetics perspective because of mate selection. Female humans have control over paternity because the male cannot know if he is the father but the female can know. That is why cultural patriarchy has evolved to some extent. Honeymoons, imposed chastity, the isolation of females in the home and punishment of females for sexual indiscretion are all examples of paternal uncertainty expressed as cultural mores.

In the examples you provided tortoises are the most interesting as it relates to my expressed theory. Tortoises are not social animals so the reproductive dynamics are different. It would seem there is no cost to a social unit as tortoises age and continue to reproduce. Old females with young apparently pose a collective cost to a killer whale pod. Older elephants apparently do not diminish the collective reproductive success of the herd so unlike killer whales there is no selective pressure for menopause.
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Re: Longevity and ftness

Postby zetreque on July 30th, 2017, 11:42 am 

I once researched this topic trying to find a similar diet of long lived species. I specifically was looking at omega fatty acids. I'd have to check back my notes on what I found but that's getting off topic.

I think the idea of reproduction and longevity is a good one.

Also turtles lay dozens of eggs so it doesn't appear that the amount of offspring is a factor either.
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Re: Longevity and ftness

Postby Athena on July 30th, 2017, 2:06 pm 

Don't humans in general age faster than elephants and tortious?

How does age affect fertility?
Fertility in women starts to decrease at age 32 years and becomes more rapid after age 37 years. ...
Older women are more likely to have preexisting health problems than younger women. ...
High blood pressure poses risks that include problems with the placenta and the growth of the fetus.
More items...
Having a Baby After Age 35 - ACOG
https://www.acog.org/Patients/FAQs/Havi ... ter-Age-35


I remember Jane Goodall reported that Flo had a lot of trouble raising her last son, and she failed to prepare him for life but allowed him to remain dependent on her. As an old woman, I will say raising children takes a lot of energy and lack of energy in our later years becomes a child care problem.

Especially before modern medicine, few of us lived past age 45, and if our life expectancy were still 45 years, we would fertile for a life time.

I am concerned about how far we should push our child bearing years considering how much energy it takes to care for children. I think grandparents play an important role in human groups, but this is about our ability to work together. If children depended on the hunting and gathering and shelter making ability of parents, as may have been so for more primitive humans, the children of older people would have been at much higher risk. It is when humans take care of their older people, that their older people can continue to be contributing members of the group. When someone else fetches the water and does the hunting and gathering and building, an older person can care for the children. But if we are constantly on the move, us older folks will sit down and go no further. We need to be stable and have control of our water and food supply to have multi generational groups that can evolve. We need to stop having children at a young age because we have a relatively short life expectancy. We get tired and can't keep up.

One more thought. Might an early end to our child bearing years, also give us a degree of population control? I suppose if we had very short life spans, our survival as species depends on having many children. Population control is unlikely to be a cause of menopause, but looking at our numbers today, it is surely fortunate we do stop having children.
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Re: Longevity and ftness

Postby wolfhnd on July 30th, 2017, 2:28 pm 

Athena population control is the theory for killer whales. It is about competition for resources within the group. So you got that right.

http://www.npr.org/sections/health-shot ... ge-of-life
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Re: Longevity and ftness

Postby wolfhnd on August 1st, 2017, 6:28 pm 

In the following study performance IQ by age at menarche was inversely proportional.

http://bmcpediatr.biomedcentral.com/tra ... entral.com

If slower maturation is associated with higher intelligence you would expect the opposite results. There are of course unlimited possible confounding factors such as nutrition, superior overall health, family stability, or other unaccounted for factors. It does however tend to bring into question my theory that selection for later sexual maturity would also select for increased overall life expectancy.
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Re: Longevity and ftness

Postby wolfhnd on August 1st, 2017, 6:54 pm 

I'm not sure social insects are a good model for life expectancy in mammals. That said the difference in life expectancy for queens (up to 30 years) and workers (a few months) does offer some insight into selection and life expectancy.

"One possible approach is to compare physiological adaptations of closely related species: Lasius niger and L. flavus are closely related, but workers experience different levels of extrinsic mortality. L. niger is a synanthropic species with a broad food spectrum [64]. This leads to higher extrinsic mortality during foraging. L. flavus has a mainly subterranean way of life, including trophobiosis with subterranean aphids [64]. This leads to a lower extrinsic risk for foragers. Following from the model, L. niger should invest less in individual workers than L. flavus. A comparison of worker life span data reveals that L. niger workers live one to two years [65], whereas L. flavus workers may live up to 10 years [66]. A comparison of biomass reveals that L. niger workers are lighter (0.58 mg dry weight) than workers of L. flavus (0.86 mg dry weight) [67]. Following the predictions from our model, the species with the higher mortality risk reduces the initial investment/production costs for workers relative to the species with the lower risk. Thus, losing one worker to an extrinsic risk is not as costly for L. niger as for L. flavus. Additionally, metabolic costs represent a measure of daily costs for the individual, including maintenance/repair, which determine the quality of the individual. The smaller workers of L. niger show lower respiration rates per mg of biomass (1.08 mm3 O2 mg−1 h−1) than L. flavus (2.04 mm3 O2 mg−1 h−1) [67]. For an interspecies comparison, the difference in the metabolic rates of L. niger and L. flavus can be interpreted as higher maintenance costs for the species with the lower extrinsic mortality as predicted by the model.

The fire ant Solenopsis invicta has a polymorphic worker caste. The head width of large workers is twice that of small workers. Large workers live 50% longer than minors in treatments with 24°C. Indeed, their maintenance costs measured as respiration rate per mg tissue at 24°C of 0.9 µl O2 h−1 mg−1 are lower than those of smaller workers 1.55 µl O2 h−1 mg−1 [12], but the absolute economic costs per individual are, due to their greater size, equal to those of at least four small workers [12]. The large workers only forage for the last 25% of their lives, whereas small and medium-sized individuals do so for about 50% at the end of their lives [12]. This again shows that the productivity/cost ratio for the worker is under strong selection. This process keeps colony efficiency at high levels. The life histories of individuals within the colonies are adjusted to keep resources within the colony. In this case, the timing of foraging in the life cycle is more limited to later ages among the larger, more expensive workers than among smaller workers, which reduces the potential loss generated by extrinsic mortality.

In Solenopsis invicta and other species, the first workers produced at the start of colony development tend to be smaller (cheaper) and shorter lived (5%) than the individuals produced later in the colony development [68], [69]. In species with single founding queens, this leads to a higher number of workers that can be reared from the limited resources. This adaptive process at the colony level maximizes early colony productivity, while increasing individual efficiency via the parallelization of tasks, and spreading the risk of forager mortality [70]. In addition, these early workers develop faster, which is also important at the early stages of the colony [71]. These findings suggest that there is a quality-quantity trade-off within the maintenance investments at the colony level, and that it is selected for in order to increase the fitness of the colony."

http://journals.plos.org/plosone/articl ... ne.0061813
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Re: Longevity and ftness

Postby wolfhnd on August 1st, 2017, 6:59 pm 

Biowizard

I have been patient let me know if you have read any of this thread :-)
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Re: Longevity and ftness

Postby wolfhnd on August 3rd, 2017, 1:12 pm 

I think we are done here. My parting comment is that I have found no compelling evidence that suggests the question of selection for longer life spans can be answered at least in specific mammals other than size and complexity. There may be some exceptions of course I'm unaware of.
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Re: Longevity and ftness

Postby Braininvat on August 3rd, 2017, 2:02 pm 

Seems to me lifespan beyond 45 would not be selected for in the environment, but would result from cultural selection. A band of hominids with a few very old members has a stronger oral tradition that can transmit more information from past generations, especially about events (that brought environmental stressors) that were prior to most members' living memory. Like, "Here's some tips on surviving the big plague of locusts..." And offer more old folk resources, like instruction in crafting tools, childcare tips, conflict management, and such like. So selection would not be at the individual level, but rather a form of group selection.
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Re: Longevity and ftness

Postby wolfhnd on August 3rd, 2017, 3:59 pm 

Braininvat » Thu Aug 03, 2017 6:02 pm wrote:Seems to me lifespan beyond 45 would not be selected for in the environment, but would result from cultural selection. A band of hominids with a few very old members has a stronger oral tradition that can transmit more information from past generations, especially about events (that brought environmental stressors) that were prior to most members' living memory. Like, "Here's some tips on surviving the big plague of locusts..." And offer more old folk resources, like instruction in crafting tools, childcare tips, conflict management, and such like. So selection would not be at the individual level, but rather a form of group selection.


Cultural group selection is undeniable. The problem is how biological group selection is defined. Complex instinctual behavioral patterns are easy to observe in some species but not so much in humans. That doesn't mean they don't exist as a form of predisposition but that I can't find much in the way of empirical evidence. We can't simply say that being a social animal is proof of kin selection. Perhaps at the level of species competition or maybe even at the group against group level but genes are passed on by individuals. An instinct for cooperation and social structure could benefit kin and non kin equally. So yes group selection is real but not as currently defined.


Take for example the killer whale as I discussed in another thread. Menopause seems to be selected for based on intra group competition for resources not mentoring. Comparatively elephants do not go through menopause because resource distribution favors older females.


The fact that there is ample empirical evidence for frequency dependent selection and little for kin selection further muddies the water. Biologically diversity appears to trump the concentration of favorable genes within a group over the long span.

That is why I'm interested in selection that favors longer life spans. It isn't clear how to differentiate the individual from the group. In the case of elephants it seems longevity helps the individual mother at the expense of even her generically related group members as she is able to gather more resources for her offspring. The group is a buffer against other environmental factors independent of kin selection. In a way favorable mutations desolve the group identity.

This is all highly speculative and more complicated than it appears at first glance and I admit to some confusion and will reexamine it when I'm functioning at a higher level.
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Re: Longevity and ftness

Postby zetreque on August 3rd, 2017, 10:25 pm 

May I offer something new to the conversation?

I've been listening to a lot of interviews of doctors talking about gut microbes and stressors. Stress changes the menstrual cycle.

Do R-selected species or K-selected species have a higher stress environment to reproduce? Just curious about how stress changes reproduction. It seems to both hinder it and pressure for helping it depending on the situation.
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Re: Longevity and ftness

Postby wolfhnd on August 3rd, 2017, 11:30 pm 

zetreque » Fri Aug 04, 2017 2:25 am wrote:May I offer something new to the conversation?

I've been listening to a lot of interviews of doctors talking about gut microbes and stressors. Stress changes the menstrual cycle.

Do R-selected species or K-selected species have a higher stress environment to reproduce? Just curious about how stress changes reproduction. It seems to both hinder it and pressure for helping it depending on the situation.


Certainly the r/K selection paradigm is relevant. Some refinement of the original theory has taken place to make age a more important factor. Like everything else in biology however it is difficult to make strict distinctions. Birds certainly invest heavily in their offspring but are not long lived. It may be better to think of investment relative to life span than comparing life spans. The relative investment can then be normalized across species with various life spans.

It is my guess that direct selection for longer life spans may only apply to animals that mature slowly and have dependent offspring. That is unlikely a complete picture because some r selected species also have long life spans. Even if we only consider animals of similar size parental investment varies widely as does growth rates. Nor does size alone explain life expectancy even if large size increases fitness. The possibility exists that life expectancy is a byproduct of selection for some other characteristic in many species and that multiple factors have to be considered. I'm finding it difficult to concentrate sufficiently to keep the possibilities in my head at the same time.

Biowizard wrote extensively on life expectancy so I will have to read through that thread. Understanding the biochemistry may stimulate some clarity if not a hypothesis.
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Re: Longevity and ftness

Postby Athena on August 5th, 2017, 9:21 am 

So no thinks the amount of energy it takes to raise a child has anything to do with the answer to the question?
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Re: Longevity and ftness

Postby wolfhnd on August 5th, 2017, 2:32 pm 

Athena » Sat Aug 05, 2017 1:21 pm wrote:So no thinks the amount of energy it takes to raise a child has anything to do with the answer to the question?


Perhaps for humans but not for turtles.

Consider that we don't even know how social animals came to be and you can see how speculative this discussion is likely to be.
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Re: Longevity and ftness

Postby Athena on August 6th, 2017, 10:08 am 

wolfhnd » July 30th, 2017, 12:28 pm wrote:Athena population control is the theory for killer whales. It is about competition for resources within the group. So you got that right.

http://www.npr.org/sections/health-shot ... ge-of-life



Very interesting. Philosophically though, I wonder why killer males make such choices. The effect may be many healthy sons, but I doubt that the female is reasoning through this and making a conscious choice. I am reading Wittgenstein at the moment and his focus on the meaning of our words and the phenomena of thinking. Increasing the survival of sons is unlikely the cause of the behavior because that would require language and thought. I think there needs to be a biological cause for the behavior and that biological cause may also result in menopause.

Also, is she favoring her sons over her daughters? Makes me think of having more sons to have a strong army. How does the mother know the difference between her sons and daughters if she does? Is this by smell resulting from hormonal differences, or appearance, or behavior differences? Is there a communication being made that affects when the female goes into menopause? Like some organisms lite up when there are enough of them. Maybe something like that causes the female to go into menopause? Sounds picky, but I am not sure the effect of something should be considered the cause.
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Re: Longevity and ftness

Postby wolfhnd on August 6th, 2017, 12:15 pm 

It seems that where there is selection for life spans it is an economic calculation.
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Re: Longevity and ftness

Postby Athena on August 6th, 2017, 12:36 pm 

wolfhnd » August 5th, 2017, 12:32 pm wrote:
Athena » Sat Aug 05, 2017 1:21 pm wrote:So no thinks the amount of energy it takes to raise a child has anything to do with the answer to the question?


Perhaps for humans but not for turtles.

Consider that we don't even know how social animals came to be and you can see how speculative this discussion is likely to be.


Not for turtles that do not have menopause, do they? But possibly for killer whales that do have menopause. The possible explanation for the killer whale menopause was the effort put into keeping the young alive.

This observation, made in your link, appears important to me.

As a female grows older and starts having calves that stay with her, however, she develops more kinship ties to those around her. "It may be that older females are more likely to share, and younger females are less likely to share food," says Croft. That would mean younger females would have more resources to lavish on their own calves.

It's clear that in these whales, older females play an important role in the survival of not just their own calves, but all of the family members they live with. "If an old female dies, her son's risk of dying in the year following her death is over eight times higher than if his mother was still alive," says Croft, "and these are adult sons, these are not juveniles, these are 30-year-old, fully grown males."


Number of off-spring matter, because it gets harder and harder to keep everyone fed and it is so easy relate to the younger mother caring for her young and not feeling obligated to care for the ones are not her directly from her. Calling this competition may be our human prespective, but that is not how I see it. I rather see it as a struggle to care for everyone, and a need to reduce that struggle to caring for our own. The daughter not feeling obligated to care for everyone, is one way to reduce her load. Another way to reduce the struggle is menopause. However, the males may not feel obligated to take care of others and then speaking of them competing is probably accurate.

PS, your reseach is looking more and more important to me.
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Re: Longevity and ftness

Postby wolfhnd on August 6th, 2017, 4:48 pm 

Athena » Sun Aug 06, 2017 4:36 pm wrote:

Number of off-spring matter, because it gets harder and harder to keep everyone fed and it is so easy relate to the younger mother caring for her young and not feeling obligated to care for the ones are not her directly from her. Calling this competition may be our human prespective, but that is not how I see it. I rather see it as a struggle to care for everyone, and a need to reduce that struggle to caring for our own. The daughter not feeling obligated to care for everyone, is one way to reduce her load. Another way to reduce the struggle is menopause. However, the males may not feel obligated to take care of others and then speaking of them competing is probably accurate.


It will probably be months before I can wade through the relevant information.

Keep in mind that elephants and whales are matriarchal societies. The role of males is to sort themselves into a hierarchy independent of the female social structure. Since all females will reproduce the males are largely responsible for maintaining genetic vigor. In humans this may be represented by males being over represented at the high and low end of the IQ range.

Random mutations are essential to evolution and there is evidence that stressed populations tend to favor individuals with poor genetic fidelity. Compared to sharks that have a low cancer and autoimmunity disease rate humans who suffered a severe bottleneck suffer from those diseases at an unusually high rate. A good example is the strange loss of ability to process gc sialic acid.

http://ucsdnews.ucsd.edu/archive/newsre ... hDrugs.asp

You often find these kind of "errors" in stressed populations that have suffered a population collapse. You can think of it as being error prone as a good thing if you need to accelerate evolution. Thinking in human terms of good and bad can be very misleading.

Theoretically it is better to maintain genetic "diversity" in males where competition will prevent undesirable mutations being passed on than in females who all reproduce. Just a few men represent an over representation of male ancestry.

http://www.ancient-origins.net/news-evo ... rld-020821

There is a book
War! What Is It Good For?: Conflict and the Progress of Civilization from Primates to Robots by Ian Morris that I think everyone should read. There is an unfortunate tendency in intellectual circles to see sugar and spice and everything nice as "good" ignoring the importance of competition. You don't have to be in favor of war to see how systems without competition tend to collapse over time.
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Re: Longevity and ftness

Postby neuro on August 7th, 2017, 12:27 pm 

Wolf,
I am not sure that - even if longevity were a threat for a species because of competition for resources - those subjects whose DNA entails more longevity would be selected against...
I mean, if a species were threatened by longevity of its members, it might disappear. But provided that the species survives, I do not see how this could select against longevity within the species.

Am I just missing something?
Because, if I am correct, then in most cases longevity would instead turn out to be profitable, in protecting and helping your progeny, thereby preserving your DNA...
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Re: Longevity and ftness

Postby wolfhnd on August 7th, 2017, 12:59 pm 

Earlier I posted a paper suggesting that worker ants have been selected for shorter life spans while a queen has a life span many times longer. It is complicated.

If a colony dies out in competition for resources with other colonies because it has invested too many resources in older workers that genetic line will end. Does that work for you Neuro?

I'm still reviewing the aging process to see if that offers any insight.
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Re: Longevity and ftness

Postby Athena on August 8th, 2017, 1:30 pm 

especially abundant in red meat
Red flags go up! I appear to have developed an auto immune problem and now wonder if this is caused by what I eat? Would our bodies get rid of the bad sugar if we change our diet?

It is fascinating that humans have a different kind of sugar than other animals! Can you get that information for whales? Long ago I read a book about our evolution beginning in a period of extreme heat and drought when our line may have retreated into the water, causing our human features to develop, such as breast that can be sucked when we are standing water and long hair that a baby can grasp, and the fact that we can swim. This would mean a basic change in diet and change in sugar content, right? In general, we should reduce the red meat we eat and increase the fish we eat.
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Re: Longevity and ftness

Postby wolfhnd on August 8th, 2017, 3:08 pm 

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Re: Longevity and ftness

Postby Athena on August 8th, 2017, 3:15 pm 

neuro » August 7th, 2017, 10:27 am wrote:Wolf,
I am not sure that - even if longevity were a threat for a species because of competition for resources - those subjects whose DNA entails more longevity would be selected against...
I mean, if a species were threatened by longevity of its members, it might disappear. But provided that the species survives, I do not see how this could select against longevity within the species.

Am I just missing something?
Because, if I am correct, then in most cases longevity would instead turn out to be profitable, in protecting and helping your progeny, thereby preserving your DNA...


You stimulated a thought in my head. It appears we may have always had the life span we have today, but this not manifested until humans gained the skill and knowledge we have today. I think that means our number of years was not increased nor decrease by biological evolution.

Grandparents are a relatively new phenomenon, researchers said today.
Until around 30,000 years ago, mankind's ancestors had lifespans that were too short for three generations to live side-by-side, according to a study.
Simply, most people died before they were old enough to have grandchildren.
Scientists said their findings show that once life expectancy began to grow, populations expanded and societies started to thrive.


Read more: http://www.dailymail.co.uk/sciencetech/ ... z4pBzmJq8S
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Re: Longevity and ftness

Postby Athena on August 8th, 2017, 8:14 pm 



Thank you so much Wolfhnd, but this time I can not keep up with you. Not only are technical terms used, but to me, the speaker sounds like he has a mouth full of mush. My bad ears and old age.

You really got my curiosity by making me aware of the fact human sugar decoration on the cells is different from other animals. It would not be so interesting if we had not broken off from the rest of the animals and developed such active brains that consume a lot of energy but because we did, I really want to understand the details. Why a different sugar and is this related to our thinking ability? Ah, oh, oh- I just remembered!
There is a direct relationship between brain energy and life span!
If our brains continued to function at the rate of babies, we would burn up and die earlier. I will try to find a link for this when I get back. It is information I came across long ago, and speaking of the sugars and thinking finally got me to remember it.

Maybe BioWizzard can wave a magic wand and organize all this information in my head with boosted memory? I would gladly pay him $10 for an ungraded brain.
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Re: Longevity and ftness

Postby wolfhnd on August 9th, 2017, 12:47 am 

Could a mod fix the title and delete this post. Looks like it is going to continue for awhile.
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Re: Longevity and ftness

Postby Athena on August 12th, 2017, 6:09 pm 

zetreque » July 30th, 2017, 9:42 am wrote:I once researched this topic trying to find a similar diet of long lived species. I specifically was looking at omega fatty acids. I'd have to check back my notes on what I found but that's getting off topic.

I think the idea of reproduction and longevity is a good one.

Also turtles lay dozens of eggs so it doesn't appear that the amount of offspring is a factor either.


Wait a minute Zetreque, aren't fats involved with reproduction? When women lose too much weight they may become infertile. And cholesterol comes in animals fats and they are essential to brain function, and we can also make our own cholesterol. Malnutrition can lead to mental retardation. Why would the nutrition be off topic? Animals handle food differently, and this has at least something to do with how long we live. We aren't going to do so well with a diet of grass. Grass may be great for cows (18-20 years) and elephants (information coming), but a grass diet is not good for humans.

Look at this surprising information I just found while checking the life span of elephants, there is a lot here to consider when figuring the controls of life spans.

Zoo females only live 19 years—about half the life span of the Myanma timber elephants, which, on average, survive until 42. What's more, the team discovered that Asian elephants bred and born in captivity died earlier than those imported into zoos from the wild.
Wild Elephants Live Longer Than Their Zoo Counterparts
news.nationalgeographic.com/news/2008/12/081211-zoo-elephants_2.html


And here is information related to our weight, health, and longevity

Imagine a place where you can be thinner, where your risk of heart and lung disease is less, where you'd be just all-around healthier. There is such a place.

Let's call it Colorado. Or Nepal. Or Peru. Anyplace with mountains.

Recent studies have indicated that there are definite health benefits to living at altitude.

Start with obesity.
http://articles.chicagotribune.com/2011 ... ng-disease


Here is a related abstract

Beside genetic and life-style characteristics environmental factors may profoundly influence mortality and life expectancy. The high altitude climate comprises a set of conditions bearing the potential of modifying morbidity and mortality of approximately 400 million people who are permanently residing at elevations above 1500 meters. However, epidemiological data on the effects of high altitude living on mortality from major diseases are inconsistent probably due to differences in ethnicity, behavioral factors and the complex interactions with environmental conditions. The available data indicate that residency at higher altitudes are associated with lower mortality from cardiovascular diseases, stroke and certain types of cancer. In contrast mortality from COPD and probably also from lower respiratory tract infections is rather elevated. It may be argued that moderate altitudes are more protective than high or even very high altitudes. Whereas living at higher elevations may frequently protect from development of diseases, it could adversely affect mortality when diseases progress. Corroborating and expanding these findings would be helpful for optimization of medical care and disease management in the aging residents of higher altitudes.


And I know you guys are going to shot me, but body mass is also related to this equation.

Bigger animals live longer. The scaling exponent for the relationship between lifespan and body mass is between 0.15 and 0.3. Bigger animals also expend more energy, and the scaling exponent for the relationship of resting metabolic rate (RMR) to body mass lies somewhere between 0.66 and 0.8. Mass-specific RMR therefore scales with a corresponding exponent between -0.2 and -0.33. Because the exponents for mass-specific RMR are close to the exponents for lifespan, but have opposite signs, their product (the mass-specific expenditure of energy per lifespan) is independent of body mass (exponent between -0.08 and 0.08). This means that across species a gram of tissue on average expends about the same amount of energy before it dies regardless of whether that tissue is located in a shrew, a cow, an elephant or a whale. This fact led to the notion that ageing and lifespan are processes regulated by energy metabolism rates and that elevating metabolism will be associated with premature mortality--the rate of living theory. The free-radical theory of ageing provides a potential mechanism that links metabolism to ageing phenomena, since oxygen free radicals are formed as a by-product of oxidative phosphorylation. Despite this potential synergy in these theoretical approaches, the free-radical theory has grown in stature while the rate of living theory has fallen into disrepute. This is primarily because comparisons made across classes (for example, between birds and mammals) do not conform to the expectations, and even within classes there is substantial interspecific variability in the mass-specific expenditure of energy per lifespan. Using interspecific data to test the rate of living hypothesis is, however, confused by several major problems. For example, appeals that the resultant lifetime expenditure of energy per gram of tissue is 'too variable' depend on the biological significance rather than the statistical significance of the variation observed. Moreover, maximum lifespan is not a good marker of ageing and RMR is not a good measure of total energy metabolism. Analysis of residual lifespan against residual RMR reveals no significant relationship. However, this is still based on RMR. A novel comparison using daily energy expenditure (DEE), rather than BMR, suggests that lifetime expenditure of energy per gram of tissue is NOT independent of body mass, and that tissue in smaller animals expends more energy before expiring than tissue in larger animals. Some of the residual variation in this relationship in mammals is explained by ambient temperature. In addition there is a significant negative relationship between residual lifespan and residual daily energy expenditure in mammals. A potentially much better model to explore the links of body size, metabolism and ageing is to examine the intraspecific links. These studies have generated some data that support the original rate of living theory and other data that conflict. In particular several studies have shown that manipulating animals to expend more or less energy generate the expected effects on lifespan (particularly when the subjects are ectotherms). However, smaller individuals with higher rates of metabolism live longer than their slower, larger conspecifics. An addition to these confused observations has been the recent suggestion that under some circumstances we might expect mitochondria to produce fewer free radicals when metabolism is higher--particularly when they are uncoupled. These new ideas concerning the manner in which mitochondria generate free radicals as a function of metabolism shed some light on the complexity of observations linking body size, metabolism and lifespan.
https://www.ncbi.nlm.nih.gov/pubmed/15855403


The new consideration is about mitochondria and production of free radicals and this is connected to the altitude where we live (Less oxygen is less free radicals), and also what we eat. Sorry if I am not doing things right, and take subjects off topic, but my mind just doesn't work as a well-trained scientist and I see all things connected and can't figure what I should ignore because it isn't on topic.
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Re: Longevity and ftness

Postby wolfhnd on August 12th, 2017, 7:14 pm 

Interesting information Athena, I would not worry about being off topic because we are shooting in the dark so to speak.
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Re: Longevity and ftness

Postby Athena on August 13th, 2017, 12:40 pm 

You mean I can follow my own inclination in your thread and not get into trouble? Yippy! Now this discussion can go on forever as one thing leads to another, and with the way people have posted here my experience of the forum may be everything I want an informal chat of science to be, full of speculation (creative thinking) and wonder, that brings out the joyful child in us, while meeting the more mature desire for logic and good reasoning as we unfold the mysteries of life.

The last link I posted said

These studies have generated some data that support the original rate of living theory and other data that conflict. In particular several studies have shown that manipulating animals to expend more or less energy generate the expected effects on lifespan (particularly when the subjects are ectotherms).


I had to look up the meaning of ectotherms and this leads to discussion of regulating temperature and I got this explanation of endotherms-ectotherms.

Why do many organisms—including you and me—keep their body temperature in a narrower range than this? The rate of chemical reactions changes with temperature, both because temperature affects the rate of collisions between molecules and because the enzymes that control the reactions may be temperature-sensitive. Reactions tend to go faster with higher temperature, up to a point, beyond which their rate drops sharply as their enzymes denature.

Each species has its own network of metabolic reactions and set of enzymes optimized for a particular temperature range. By keeping body temperature in that target range, organisms ensure that their metabolic reactions run properly. https://www.khanacademy.org/science/bio ... ectotherms


Next step, is there any thing else to say about temperature and life span? Yes, there is....

The second law of thermodynamics states that within a closed thermodynamic system the entropy will increase over time until it reaches thermodynamic equilibrium. This increase in molecular entropy over time within living organisms has been proposed, under the assumption that the second law of thermodynamics applies to open systems, to increase susceptibility to age-related disorders and thus essentially equate, at a high level of abstraction, to the ageing process (Hayflick 2007). Other authors have argued that ageing is due to an increase in molecular disorder due to an increase in thermodynamic entropy (Demetrius 2013). One of the factors known to affect thermodynamics is temperature, and therefore it has been long speculated that it may influence the ageing process with organisms ageing faster at higher temperatures due to more molecular damage being generated (Conti 2008; Liu and Walford 1972; Rikke and Johnson 2004).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4486781/


Now would climate change be involved with the extinction of dinosaurs?

The dinosaurs’ long reign was not ended swiftly but by torturous millennia of climate change before and after a giant asteroid slammed into Earth, scientists have said. https://www.theguardian.com/science/201 ... rike-study


Does the climate temperature affect fertility?

Summer temperature extremes reduce conceptions in the southern United States, explaining a substantial part of the observed seasonal birth pattern. Extreme cold shows no evidence of affecting conceptions. The results also show significant seasonality in births even after accounting for temperature. Controls for monthly temperature do not explain the persistent spring peak in births in northern Europe. This finding suggests that other factors play an important role.
https://www.ncbi.nlm.nih.gov/pubmed/8875063


How climate affects our life span.

Not only is mortality higher in the winter but a very cold winter produces a higher number of deaths. During the summer, according to Lerchl’s analysis, heat spells do lead to more deaths; but the increase is relatively small compared to deaths from the cold.

https://web.stanford.edu/~moore/HealthB ... armer.html



Conclusion- there is a range in climate temperature where we do best.
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