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

learn more… | top users | synonyms (2)

0
votes
0answers
5 views

Why the position of simple sequence repeat at the gene and related transcript sequences are different?

I'm working on the simple sequence repeat (SSR). I found that just one region (about 21 bp) with SSR motif in a given gene. This gene has multiple transcripts, which the same SSR motif was located in ...
2
votes
1answer
45 views

If crocodiles are k-selected, why do they supposedly “not age,” as in avoid senescence?

I recently saw a few sources stating that Crocodiles do not biologically age, implying negligible senescence. Basically, a 70 year old crocodile is in the same physical/health condition as a 7 year ...
0
votes
0answers
55 views

Disposable Soma Theory and the case of the contraposition

According to August Weismann (1889), Kirkwood and Holliday (1979): Because of the evolution of an organism that is segregated into soma and germ cells, soma becomes disposable, and in the face of ...
38
votes
8answers
6k views

Why does evolution not make our life longer?

Why does evolution not make life longer for humans or any other species? Wouldn't evolution favour a long life?
2
votes
1answer
53 views

Why the length of UTR in the genomic sequence of gene X is too much longer than the same region in the corresponding Refseq mRNA sequences?

I'm browsing in the UCSC genome browser and found that the UTRs length of KIAA0040 gene in the genomic sequences is too much longer than the corresponding the Refseq mRNA sequence. In fact, the total ...
1
vote
0answers
14 views

Do “old” or damaged organs leak out damaging substances? [closed]

I'm wondering whether "old" or damaged organs leak out some substances (like free radicals or others) that damage other organs. For example consider a 50 years old healthy person. Assume for the sake ...
3
votes
1answer
151 views

Why are cancer rates low in large animals?

Large animals generally have more cells and live longer than smaller animals. For example, bowhead whales live up to 200 years and weigh up to 100 tonnes, as opposed to humans (living ~71 years and ...
3
votes
2answers
174 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 ...
0
votes
0answers
32 views

Hair whitening with age explanation

I don't understand, why the hairs are whitening with age? Popular explanations look formal to me. For example, an explanation by stopping of melanin production is just a rephrase. Melanin is a ...
0
votes
0answers
24 views

Determination of Ageing by ECG inclusions/exclusions?

I am studying ageing and considering ECG signal because of its high sensitivity in theory (escardio). Some factors Sensitivity Gender Medical treatment ... Benchmark: RTG dental + wrist ...
0
votes
0answers
15 views

Why do multicellular organisms die of old age? [duplicate]

According to this answer, bacteria do not really age, just some offspring of the bacteria have more damage and die to let other bacteria live. Most cells in an animal are "new" cells and are not the ...
0
votes
1answer
138 views

Does the second law of thermodynamics cause aging? [closed]

What is the current understanding as to why organisms age and die? In the following explanation on Ask an Engineer, entropy is not even considered (despite it being answered by an engineer). Unless ...
0
votes
0answers
83 views

Known ways to modify the genetic structure of the 13 loci used in CODIS

After reading the answer to Does our DNA change during our lives?, I was wondering if and how it would be possible to change the structure of the 13 loci that are used in the CODIS database, in such a ...
23
votes
3answers
4k views

Do all organisms have to die?

I understand (a little) that there are biological clocks and reason that after a certain amount of time organisms die. I'm wondering if that is something inherent in our DNA or in biology/chemistry in ...
33
votes
6answers
1k views

Why do we age? or Do we have a theory of senescence?

There seem to be a number of ideas about why we age. Hypotheses include the gradual accumulation of cell metabolic products affecting organism function and the reduction of telomere length during cell ...
0
votes
0answers
46 views

What is the term for being younger than the body age?

I remember that I once attended a seminar in which the speaker talked about the heart rate of different kinds of butterflies. Normally, the heart rate of the adult butterfly will be more complex than ...
1
vote
3answers
100 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 ...
1
vote
0answers
29 views

Senescence in space

How is senescence of individual eukaryotic cells and tissues affected by gravity and zero-gravity environments? In other words, can eukaryotic cells live forever in space (given the appropriate ...
2
votes
0answers
48 views

Hydra immortality

Recent research on immortality ha been on an organism named Hydra. I have heard about it being related to some FoxO gene, which has been found in several other organisms but how does telomerase affect ...
6
votes
1answer
487 views

Do people grow shorter as they age, how common is it, and what triggers it?

Is it true that people become gradually shorter as they age? If it is, is it more common in one gender than the other? And is it known what triggers this? (Considering that the "shortening" probably ...
15
votes
1answer
3k 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 people'...
4
votes
0answers
77 views

Why do people die? [duplicate]

what is the reason people die naturally even though they have no known disease? I see people become physically weak at times they get old and die eventually in case they are not attacked by any known ...
10
votes
3answers
708 views

Have there been studies done to test Immortality of cancer cells in culture?

This website on cultured cancer cells () says cancer cells may be immortal. I am wondering if there has been any research done to find if cancer cells are really immortal. How old is the still ...
3
votes
2answers
62 views

Would a person live longer, if such a person lived in a planet with lower gravity? (say, Mars) [closed]

I was wondering: some companies plan to colonize Mars, many of us know. But if one were to live on Mars, would this person live longer? It seems to me that a lower gravity would mean less overall ...
0
votes
0answers
155 views

What is the reason our body stops producing collagen/elastin?

Stops producing elastin at around 14 years old. Collagen -- at 25-30. What is the reason?
2
votes
1answer
54 views

Do Blanding's Turtles die of old age?

I have recently found articles and various claims that turtles (Blanding's turtles as an exact example) could possibly live indefinitely. http://discovermagazine.com/2002/jun/featturtle This is said ...
6
votes
2answers
247 views

Can plants live forever? [duplicate]

I know that some plants die for old age like a lettuce. But there are trees like Baobabs or larger Ficus in the tropics of whom we don't know their age. And trees like spruce reaching 9950 years old, ...
9
votes
2answers
116 views

How well does the radius of a tree correlate with its age?

I'm looking for a cheap non-invasive ways to approximate the age of a tree (a birch). Measuring the radius pops up in the mind as the first alternative. How would one do that? Measure at multiple ...
5
votes
2answers
354 views

What determines the autumn leaf color?

It is autumn out there. Green, brown, red, yellow, and mixed-colored leaves drop from the trees to the ground. What determines the colors of the leaves? Wikipedia tells me Leaf senescence is the ...
2
votes
0answers
25 views

What is the role of RAGEs?

According to articles I read, AGEs (advanced glycation end products) activate RAGEs (receptors for AGEs). This activation increases the ROS (reactive oxygen species) levels in the cells. 2003 - ...
2
votes
1answer
45 views

About modern dating techniques

In a comment to this question, it was said that Radiocarbon dating won't work. For a start the tree needs to be dead, which since you're not using the rings I'm assuming it isn't. Also the atomic ...
3
votes
1answer
83 views

What are senescent cells doing in our bodies? [closed]

I'm reading a paper that mentioned the elimination of senescent cells delays aging. I'd like to receive more information about it. The Baker study published in Nature demonstrates that targeted ...
4
votes
1answer
182 views

Circulating factors affecting human health/longevity

Circulating factors present in young mice have been shown to promote rejuvenation of aged mice, suggesting that tissues have inherent capabilities to regenerate, and circulating factors may be ...
4
votes
1answer
51 views

Do we know if RHEB is more sensitive to some amino acids than other amino acids?

RHEB (Ras homolog enriched in brain) senses amino acid levels in order to recruit mTOR. See this review describing the process of how RHEB recruits mTOR. So does RHEB have differential selectivity ...
8
votes
3answers
1k views

Is there any kind of immortality in plants?

I asked a question about immortality of hydra and learned good things about senescence. Now I would like to know about immortality in plants, if there is some kind of immortality in plants and how ...
7
votes
2answers
2k views

Can human organs be transplanted indefinitely?

I watched this movie, where they rented hearts to people for a year. I wonder if it is possible to transplant a heart indefinitely from person to person, or does the heart have a lifetime? So, do ...
2
votes
2answers
165 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 ...
81
votes
1answer
8k 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
votes
2answers
992 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 ...
16
votes
3answers
1k 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 ...
10
votes
1answer
260 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 ...
3
votes
1answer
173 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 ...
10
votes
1answer
13k 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 ...
21
votes
1answer
880 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 ...
9
votes
2answers
568 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 ...
2
votes
0answers
32 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 ...
6
votes
1answer
79 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 ...
4
votes
2answers
506 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 ...
0
votes
1answer
99 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 ...