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70 votes
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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 ...
Mowgli's user avatar
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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 ...
Meep's user avatar
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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 ...
AliceD's user avatar
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10 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 ...
Phlya's user avatar
  • 201
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 ...
CDB's user avatar
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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 ...
theforestecologist's user avatar
6 votes
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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 ...
Greg's user avatar
  • 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 ...
AliceD's user avatar
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4 votes
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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, ...
canadianer's user avatar
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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 ...
AliceD's user avatar
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4 votes
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Why do old willows have so many broken limbs?

These trees appear to be Salix x fragilis AKA crack willow or brittle willow. The form is more upright and taller than the common weeping willow, but has drooping pendulous thin branches on the lower ...
bob1's user avatar
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3 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 ...
theforestecologist's user avatar
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....
Alex I's user avatar
  • 536
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 ...
theforestecologist's user avatar
3 votes

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 ...
Dapper Lad's user avatar
3 votes
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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 ...
anongoodnurse's user avatar
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 ...
Maddie Matei's user avatar
3 votes
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What causes the activation of "Late acting deleterious genes" in late age but not in young age, whose accumulation causes ageing according to Medawar?

It's not that genes become 'activated' at late age, but that they aren't relevant until late age, so high performing versions aren't selected for and poor performing versions aren't selected against. ...
timeskull's user avatar
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2 votes
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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 ...
Ooker's user avatar
  • 578
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 ...
David Bahry's user avatar
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 ...
devon56's user avatar
  • 36
2 votes
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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 ...
jzx's user avatar
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2 votes
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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 ...
Fabio Marroni's user avatar
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 ...
user338907's user avatar
  • 4,738
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://...
Bryan Krause's user avatar
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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 ...
Roni Saiba's user avatar
1 vote

Is reverse senescence/"anti-aging" actually scientifically possible among humans yet?

Keeping in mind that this was a very small, not especially well-controlled preliminary/exploratory study. Because life expectancy was increased by ~2.5 years - or got ~2.5 years younger biologically, ...
Retardi Grade's user avatar
1 vote

Is reverse senescence/"anti-aging" actually scientifically possible among humans yet?

Not within the next two decades, at least (assuming you meant nearly total reversal of the effects of physiological aging). Any further than that is impossible to predict, since we are likely only a ...
VVayfarer's user avatar
  • 258
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 ...
Dr. Kawashima's user avatar

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