68
votes
Accepted
What is the longest-lasting protein in a human body?
Crystallin proteins are found in the eye lens (where their main job is probably to define the refractive index of the medium); they are commonly considered to be non-regenerated. So, your crystallins ...
- 1,893
22
votes
What is the longest-lasting protein in a human body?
I like Mowgli's answer, because it is a non-obvious example. However I would also point out that there are many, many protein-based structural components in the body that we know do not regenerate due ...
- 2,939
17
votes
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What makes learning more difficult as we age?
The answer(s) to this question can fill libraries. But I can give a few pointers here, as the question is relevant and timely, giving the tendency to an ever increasing life expectancy of the general ...
- 52.3k
12
votes
Why are cancer rates low in large animals?
Short answer
Large animals do get cancer. They may contract cancer with an incidence less than that estimated by absolute cell numbers, but there seems to be a lack of data on cancer rates in large ...
- 52.3k
9
votes
What is the longest-lasting protein in a human body?
A very interesting example are the cohesin molecules holding sister chromatids together in the oocytes (so only applicable to females, sorry!). Cohesion is established in utero, and these molecules ...
- 191
8
votes
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Isn't biological immortality strictly speaking impossible?
Good question.
There are many organisms that are technically biologically immortal. However, I would like to point out that the definition of biological immortality is this:
...cells that are not ...
- 1,826
6
votes
Does the second law of thermodynamics cause aging?
Second law of thermodynamic and ageing
The second law of thermodynamic applies to closed system. Organisms are not closed system. The second law of thermodynamic is a fundamental principle of our ...
- 67.9k
6
votes
Do immortal organisms exist?
The immortal jellyfish (Turritopsis dohrnii) is capable of biological immortality.
It's one of few known species capable of reverting completely to a sexually immature, colonial polyp stage after ...
- 29.6k
6
votes
Accepted
What is the best method to check for differential gene expression in large dataset? I want to identify aging differentially expressed genes
A standard pipeline for DGE would be Salmon for (pseudo)mapping + DESeq2 for statistical analysis.
Salmon is one of a set of modern, fast and accurate mapping software. Requires a transcriptome to be ...
- 224
4
votes
How much does hearing deteriorate with age?
Hearing sensitivity deteriorates with age, which is called age-related hearing loss, or presbyacusis. Presbyacusis is characterized by elevated hearing thresholds. Especially the high frequencies are ...
- 52.3k
4
votes
Do immortal organisms exist?
Examples found in plant world also- especially those with high vegetative reproduction and regeneration property.
https://en.wikipedia.org/wiki/The_Great_Banyan
Great banyan tree in Indian botanic ...
- 2,669
4
votes
Why do humans lose subcutaneous fat tissue with age?
Short answer
We do not loose fat (cells) as we age; on the contrary - we tend to gain fat by about 1 or 2% per decade. The place where it gets stored does change; instead of going into subcutaneous ...
- 52.3k
4
votes
Accepted
Why might long telomeres be selected for in laboratory mice?
Their arguments for increased telomere length in lab mice are:
Rate of tumour formation is dependent on the number of cells within an organism. Additionally, tumours take time to form. Therefore, ...
- 17.6k
3
votes
What is the longest-lasting protein in a human body?
In terms of the common/abundant proteins, the answer would have to be elastin.
The turnover is extremely slow, with a half-life of 74 years (https://www.elastagen.com/media/The_Science_of_Elastin....
- 534
3
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Isn't biological immortality strictly speaking impossible?
The whole "science" behind telomeres is rather flaky, for example:
Is Telomere Length a Biomarker of Aging? A Review
Although telomere length is implicated in cellular aging, the evidence ...
3
votes
Accepted
Excercise and fitness in old age
Not all "wear and tear" is bad. I will provide only one example. Trust me, I can provide many more, but I think one is sufficient to answer your question.
Exercise (against resistance, e.g. even ...
- 24.5k
3
votes
Why does hair turn grey or white, and why does it happen later for some?
Stress has finally been definitively shown to be a cause of graying hair.
As such, delay or acceleration of onset could be due to stress.
Work by Zhang et al. (2020) (postdoc in Ya-Chieh Hsu's lab ...
- 29.6k
3
votes
Why does evolution not make our life longer?
I am assuming that by longer life, you mean slower aging, because evolution can do little if a mountain falls on a person!
So, why don’t organisms have slower, or better, zero rate of aging?
The ...
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3
votes
In life history theory, does trade-off between reproduction and growth and maintenance imply longer health span for a sexually inactive organism?
I am not sure if life span could be extended in such circumstances but the probability of survival could probably increase, given the high metabolic costs of growing and raising offspring. I work ...
- 173
2
votes
Source of information on the evolution of aging/senescence
I don't know about just one source that fits everything you've asked, so here's a custom bibliography to get you started instead.
General Sources
I first learned about biogerontology from the ...
- 494
2
votes
Would a person live longer, if such a person lived in a planet with lower gravity? (say, Mars)
Probably not. There's a thing called Hayflick limit, which is basically a limit of life expectancy caused by a shortening of telomeres with every cell division. And since most of our cells complete ...
- 166
2
votes
Accepted
What is the term for being younger than the body age?
Neoteny
Neoteny (/niˈɒtəni/), also called juvenilization, is the delaying or slowing of the physiological (or somatic) development of an organism, typically an animal. Neoteny is found in modern ...
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2
votes
Accepted
Saving lives by "conjoining" people
As mentioned in other answers, the problems with accomplishing this are manifold but primarily relate to the immune systems of the donors and recipient. While it may seem like anastomatizing the ...
- 1,788
2
votes
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Whitening of hair at old age
It would be incorrect to assume that
every change has a significance
from an evolutionary point of view. In many cases, the changes could be happening at an age where it does not affect it's ...
- 36
2
votes
Is reverse senescence/"anti-aging" actually scientifically possible among humans yet?
Short Answer
You might be interested in learning about telomeres, telomerase, and telomerase gene therapy.
For example, Boccardi & Herbig (2012): describe a mouse study in which they used ...
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2
votes
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Identify brain junk - What are all the known intracellular and extracellular substances which build up with age and clog the brain?
Another example is the paired helical filament of Alzheimer's disease, so-called because neurofibrillary tangles have a ribbon-like structure when viewed under the electron microsocope.
It is now ...
- 4,668
2
votes
Accepted
Aging: Only humans have grey hair?
I don't think it is restricted to humans. Dogs lose hair pigment as well, usually around the muzzle.
This work used graying of hair to discriminate senior dogs.
I don't know which other mammals lose ...
- 707
2
votes
DNA damage theory of aging and sex
I've answered a related question, which was wondering why older people get more cancer from accumulated DNA damage and yet their children aren't immediately susceptible to it, here:
https://...
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2
votes
Evidence against aging caused by loss of information in genome and epigenome in humans?
By loss of genome, I think he is referring to the shortening of telomeres. This
study compares the length of telomeres of human epidermal cells. The authors report that over time, the telomeres do ...
- 623
1
vote
Why do humans lose subcutaneous fat tissue with age?
How sad, you didn't get a response. You got a person saying that people don't lose total body fat with age (which you never claimed, or ask about), and a person saying that visceral fat gain isn't ...
Only top scored, non community-wiki answers of a minimum length are eligible