Young blood does not reverse aging in old mice, UC Berkeley study finds
news.berkeley.edu
news.berkeley.edu
> The researchers think that many benefits seen in old mice after receiving young blood might be due to the young blood diluting the concentration of inhibitors in the old blood.
How can these things be compatible? If it were diluting the inhibitors, that should have shown up as an improvement in the old mice, no?
Imagine that the effective (deleterious) dose of these inhibitors is, say, 10% of the amount found in old mice. So an equal exchange between two mice is enough to provide an effective dose to the young mouse, but not enough to eliminate an effective dose to the old mouse.
keyword is 'slight' improvements. it's a poorly written sentence.
Yes, there study did show that young blood can not stop the effects of old blood.
However if someone were going to get transfused with young blood the amount of old blood in their system would decrease, so then, presumably, you would see anti-aging effects.
I don't know why they didn't present the research like that. It seems like they don't want to say it or I'm just missing some logical step in my thinking.
My personal theory is older organisms get colonized by all kinds of bacteria that might trigger or speed up the breakdown the body.
You have to get so many things just right for immortality to 'work', i.e. to actually be useful in a survival context. It does no good for creatures to not age if they lose a significant amount of viability.
But real immortality in the complete reversal of aging, I think would be an immense advantage. Instead of having to teach your young over a very short period of time the tricks they need to be viable adults, creatures could super-specialize. One creature could supply all the food needed for a huge colony. They'd just get better and better at exploiting their niche and other creatures could find other niches.
I think if intelligence hadn't 'gotten there first', immortal creatures would be running the show.
We call this a "single point of failure".
Everybody becomes T-shaped.
In the case of a supposed aging gene, consider that genes themselves preferentially want to exist in more fit organisms. If a gene could somehow manage this (i.e. be embodied with more fit genes), it will itself spread. But this is exactly what an aging gene does! Consider how an advantageous gene spreads through a population. This spread is a function of the number of generations that have passed. So a gene that could speed up the passing of generations will increase its own likelihood of existing in more fit organisms (increasing its own fitness), as advantageous genes within the population spread faster and are more frequently "paired up" with the aging gene. But the subpopulation with the aging gene is more fit than the subpopulation without it since the time for advantageous genes to spread is decreased, and so the aging population overtakes its counterpart.
You don't need extra genes or information to prefer organisms that age out of reproductive fitness. If advanced age during reproduction confers lower fitness, then the offspring are automatically less fit. While you could argue that there would be a competition for resources amongst the young offspring, this isn't much different than other scenarios that produce less fit or disabled offspring.
The sharing of genes within a population creates a nice analogy between the population and a single organism. Programmed death for members of an organism is a standard feature of evolution. It's not implausible that such a feature exists at the level of population as well.
https://en.wikipedia.org/wiki/Evolution_of_ageing
None of these has been proven or widely accepted, and the entire class of theories has many rebuttals. They are interesting to consider, though.
What you're missing is that 'good' is defined with respect to a goal. From an evolutionary standpoint (whatever that really is), the complete extinction of all life is just one possible way things could be and it is as good as any other way things could be. From a human perspective, this is awful. As is any future where humans don't exist.
You seem to have understood it as: "A species dying off very easily is sometimes a good thing for evolution." In response to this, your response is justified.
When in fact, what m3ta is saying is: "Members of a species dying very easily is sometimes an evolutionary advantage for that species." In response to this, your response is a non-sequitur.
That's terrifying.
https://en.wikipedia.org/wiki/Parabiosis#Parabiotic_experime...
Also did some other fun things such as mass killings of rats using mini-guillotines, harvesting bones and doing amateur brain surgeries while other rats watched restlessly and anxiously peeped from the smell of blood.
This kind of stuff can mess with your sanity. For me it was a converse of how serial killers injure animals when they were children.
Still have nightmares sometimes.
While, yes, everything can be a variable, the effect wouldn't be big. I imagine the person running the lab had done this before and has gotten good results: rats are expensive and a hassle to keep. If his experiments had been 'screwed over' because of practices like that, his PI probably wouldn't be able to gather enough useful data to afford funding for animal use.
What a sad situation to be caught up in.
http://blogs.discovermagazine.com/80beats/2011/11/21/helpful...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633676/
> Fetal cells migrate into the mother during pregnancy. Fetomaternal transfer probably
> occurs in all pregnancies and in humans the fetal cells can persist for decades.
> Microchimeric fetal cells are found in various maternal tissues and organs including
> blood, bone marrow, skin and liver. In mice, fetal cells have also been found in the
> brain. The fetal cells also appear to target sites of injury. Fetomaternal
> microchimerism may have important implications for the immune status of women,
> influencing autoimmunity and tolerance to transplants.Immortal of course doesn't mean impervious. A long, unaged, productive life span would still require food, water, shelter, and some amount of safety.
One of the most common (and usually loudest) arguments I hear against general species-wide immortality is the resource limitations of Earth. Well, if we can live for a thousand years or ten thousand years, what's the purpose of not traveling interstellar distances? The major limits are mostly the lifespan and related issues after all. The rest is mostly engineering. We're good at engineering our surroundings.