Tagged Questions

The process of biological aging or the state of an organism being biologically old.

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2
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2answers
97 views

Do couples having children later in life act as an evolutionary mechanism?

Ok, this may be just wild nonsense and I have to warn that my knowledge on the subject is limited. I was reading about how in some countries people choose to have children later in life. After that ...
44
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1answer
5k views

Do bacteria die of old age?

I know that the cells of mammals at least stop dividing when they are old, and then die a programmed cell death. Then other cells have to replace them. But in a bacterial colony, each cell ...
3
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2answers
59 views

In practice, do fishes die from old age?

I was watching sea birds eating fishes and wondered if fishes actually died from old age, or if they are all eaten before this can happen? I reckon some big predator fishes must be able to live long ...
2
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1answer
78 views

Senescence, immortality and evolution?

Many have heard about the fabled "immortal" jellyfish, Turritopsis dohrnii, which doesn't die from aging (senescence) and can revert the aging process indefinitely. It is rather remarkable that only ...
2
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0answers
25 views

How can stem cells be counted in body?

In the study of supercentenarian woman here, it was found that all her blood cells are formed from only two stem cells (ancestor stem cells). How scientists can distinguish cell ancestors? Aren't ...
19
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7answers
4k views

Why does evolution not make our life longer?

Why does evolution not make life longer for humans or any other species?
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2answers
61 views

Does increased physical activity increase the rate of cell division?

Ever since learning that the shortening of telomeres is linked to aging I've tried to figure out what causes cells to divide, and if it's possible to slow down the rate of cell division through life ...
2
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0answers
25 views

Source of information on the evolution of aging/senescence

Do you know a good review (published peer-reviewed or an online course or whatever) that offers a good overview of all hypothesis explaining the various patterns linked with aging? I'd like this ...
3
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0answers
26 views

Effect of Aging on SA node's sympathetic fibers

I am trying to understand the effect of aging on the sympathetic fibers of SA node. I know that aging shifts the vagal curve to left in frequency due to aging. However, I am interested if aging has ...
1
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0answers
60 views

What is the name of systemic tension of muscles?

I meat a overtrained friend (25 years old) who cannot rest. He has all muscles and most of the skin very tense. He is practising regularly in gym and sleep badly. He moves like a stick figure and has ...
3
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1answer
67 views

Do people with gout live longer?

Antioxidants reduce damage to tissue (by scavenging the free radicals) and thus may reduce ageing.It is known that Uric acid is a very good antioxidant. People with gout have excess accumulation of ...
1
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2answers
65 views

In what ways can mechanisms of apoptosis be damaged?

How many ways can an Apoptosis mechanism be made disfunctional or irreparably damaged? If a cell has damaged Apoptosis mechanisms and it divides will its daughter cells have such damage?
1
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3answers
65 views

Does DNA influence death (e.g. by cell aging)

I know that we age because of errors in the cell replication process and these errors eventually leads to death. If we exclude environmental factors, are there any other factors that can cause these ...
0
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1answer
35 views

Fibrinous inflammation, exudate and scarring in monotonous movements and ageing

I have palpated many hard organs during my work and studies. I have seen many young and old people who have hard organs, like very hard shoulder - very common. I have interviewed some of them, some ...
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0answers
33 views

Where people age at slower pace - mountain or seashore [closed]

where people live longer - mountain or seashore? If mountain then at what elvation they age at a slower pace?
2
votes
2answers
67 views

How does the telomere repeat sequence vary in Eukaryotes?

Question: How does the telomeric repeating sequence vary in non-vertebrate Eukaryotes? If you know the repeating sequence of a given species I would appreciate hearing it. Background: Telomerase is ...
3
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1answer
41 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
0
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0answers
35 views

Can we define biological age?

How can we define ageing from a biological standpoint without making an appeal to chronological age? Related, but less important, are there any metrics we can use to determine someone's biological ...
0
votes
1answer
31 views

How does the body repair extracellular damage caused by glucose?

So we know that glucose is an aldehyde that can cause cell damage to the lysine and arginine residues on proteins through the Maillard Reaction (among other damaging reactions that glucose ...
4
votes
2answers
131 views

Is solving cancer required in order to avoid aging?

When the telomerase enzyme is not active the telomere shortens every time the cell duplicates leading to a reproductive limit (Hayflicks limit). On one hand this is a believed reason for aging. On the ...
3
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2answers
845 views

Cell life: division for immortality or reproduction with aging

Are the two cells that are derived from one cell, ‘twin sisters’ or a ‘mother and a daughter’? In other words, can a cell really be divided to live an "immortal" life or is cell reproduction the ...
4
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1answer
221 views

How much does the Hayflick limit/telomere length vary across taxa and within humans?

Since they seem to be quite connected, I'm curious if anyone knows of research comparing the Hayflick limit (and presumably by extension telomere length) between different taxa. I've heard the ...
6
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1answer
62 views

How well supported is the hypothesis that aging is mainly caused by the number of mutations in tissues?

I heard the hypothesis, that the (main) reason of aging is the increasing number of mutations in body tissues. The higher the number of mutations is, the older tissue is. Is this true? And how well ...
0
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2answers
123 views

How is it that the WI-38 cell line isolated by Hayflick in 1962 is still very much around and not affected by the 'Hayflick Limit'?

I have searched the net and I have not been able to come up with an clear answer. Edit: Here is the para quoted from Nature http://www.nature.com/news/medical-research-cell-division-1.13273 "So began ...
3
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1answer
74 views

Hibernation, Metabolism and Aging

People are beginning to seriously research space travel applications of therapeutic hypothermia, specifically for reducing metabolism and stress on humans traveling to Mars. It seems that as you ...
1
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1answer
57 views

Telomere elongation methods?

What sort of telomere elongation methods are there currently? Would this stop aging? (edit: No, probably) I couldn't turn up anything good on google. I was thinking that maybe you could sequence ...
6
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2answers
373 views

Do immortal organisms exist?

Do organisms exist that are able to live indefinitely if they are not killed by external factors? Under external factors I would consider things like predators and natural disaster but not illness by ...
9
votes
1answer
172 views

How are new people created from the DNA of an aged person. i.e. Why are we young?

The question "why do we age" has been asked numerous times. But why are we young? The cells of the adult human being are an age (time>0), but how can old cells create new cells that are younger than ...
6
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1answer
536 views

Exercise causes number of cell divisions to approach Hayflick limit faster? And hence shorten life expectancy?

A world class athlete spends a lot of time performing intense exercises. Correct me if I'm wrong, but I assume that these intense exercises causes significant damage to the athlete's cells, but with ...
6
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3answers
566 views

Is there any kind of immortality in plants?

I asked a question about immortality of hydra and leaned good things about senescence. Now I like to know about immortality signs in plants. If there is some kind of immortality in plants its process ...
13
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4answers
2k views

Why is the Hydra Biologically Immortal?

I have heard that the Hydra organism is biologically immortal (later I found that there are more immortal organisms). Now I know that its immortality is related to its telomerase. The thing is that we ...
3
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0answers
79 views

Papers linking telomeres and aging [closed]

I'm currently writing a piece of work about telomeres and aging, and wondered if you could share some good papers you've either read or know of.
4
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1answer
97 views

Difference In Telomeres Between A Thale Cress Plant And A Methuselah Tree

From what I have read and understood telomeres cap off how many times a cell can divide before it can no longer divide and that is what causes aging. A thale cress plant apparently has a life cycle ...
6
votes
1answer
7k views

Do crocodiles age?

I was watching a talk by Michio Kaku and he mentioned that crocodiles (or possibly alligators, I forget offhand) don't actually age -- they can die, but they essentially go through no aging process ...
3
votes
2answers
213 views

Does the speed of electrical impulses through neurones decrease with age?

From what I read on the NatGeo app, it stated that the speed of the electrical impulses that are sent by a neurone will be approximately 332 kilometers per hour. Will the speed of this electrical ...
5
votes
1answer
194 views

What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?

I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years. Can someone explain in ...
6
votes
3answers
166 views

What reasons allow for women to outlive men?

It is a well-known fact that women tend to outlive men. I often hear people unscientifically stating that men generally generally die younger because of the higher stress encountered in their work ...
2
votes
1answer
63 views

Age-associated neurodegenerative diseases

Age-associated neurodegenerative diseases encompass Alzheimer's Disease and Parkinson's Disease. What other neurodegenerative diseases could be described as age-associated? Multiple Sclerosis? Brain ...
14
votes
2answers
2k views

Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
4
votes
1answer
168 views

Is cell senescence in culture comparable to that in vivo?

A cell is 'senescent' when is has permanently left the cell-cycle. This can be caused by stresses, or by reaching the 'Hayflick limit' (the cell has reached its replicative lifespan, as defined by its ...
4
votes
1answer
74 views

During human ageing, which immune cell sub-types are most affected?

It is now well established that human ageing is accompanied by an increase in systemic, low-grade (chronic) inflammation, sometimes termed inflammaging (Franceschi, 2007). This is in part due to more ...
13
votes
1answer
851 views

Are human bodies programmed to die?

Following from this question: What is the evolutionary advantage of death?: Is there any evidence that human bodies have systemic self-destruction built into their developmental program? I'm not ...
11
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1answer
1k views

Why does hair turn grey or white, and why does it happen later for some?

The question is pretty simple: what is happening molecularly when hair turns grey or white? I would imagine that it is due to the lack of a particular compound. I'm also interested in why some ...
3
votes
1answer
424 views

Could inhibition of progerin formation slow the rate at which a body ages?

According to wikipedia, progerin is activated in senescent cells. The protein itself is known to be the cause of a rare affliction 'progeria' - a disease marked by accelerated aging of the body. This ...
12
votes
1answer
176 views

Have any mutations or genetic loci been associated with exceptional longevity in humans?

Individuals that avoid age-related diseases into later life are known as 'exceptional survivors', and have increased longevity compared to their 'controls' (those that were born at a similar time, yet ...
18
votes
1answer
522 views

Do trees age on a microscopic level?

Most animals age via at least two mechinisms: at a "macroscopic" level, basically wear and tear to the point where (on evolutionary time scales) it's more genetically advantageous to optimize for ...
15
votes
3answers
472 views

Why do some trees have a life span, while some don't?

I have heard that there is no limit on the growth of trees, but then why do some trees, such as boxelders and poplars, tend to live shorter than redwoods, for example? Some advertisements for improved ...
7
votes
3answers
122 views

Free Radicals for aging

From my understanding free radicals play a slight role in ageing. In what ways are they so damaging, and can a restricted diet reduce production of free radicals?
0
votes
1answer
79 views

If inhibiting S6 kinase decreases protein translation, then could inhibiting S6 kinase could possibly slow down long-term potentiation in neurons?

From http://en.wikipedia.org/wiki/P70S6_kinase... Phosphorylation of S6 induces protein synthesis at the ribosome. P70S6 kinase is in a signaling pathway that includes mTOR (the mammalian ...
4
votes
0answers
39 views

RHEB senses amino acids in order to recruit mTOR. Do we know if RHEB is more sensitive to some amino acids (like methionine) than other amino acids?

See http://www.ncbi.nlm.nih.gov/pubmed/21157483 for the full paper describing the process of how RHEB recruits mTOR. We also discussed this in Matt Kaeberlein's class yesterday and I posed this ...