Evolution of aging - could it be adaptive? - Peter Lidsky
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- Опубліковано 29 чер 2024
- In this video I chat with Peter Lidsky, a postdoctoral fellow at the University of California, San Francisco (UCSF), where he works on his interests in the role of viruses in aging and evolution.
Before that, Peter studied enteroviruses and then moved to Switzerland, where he joined the laboratory of Christian Lehner at the University of Zurich. There, he switched his focus to Drosophila melanogaster, a model organism for studying gene regulation and development. In 2017, Lidsky moved to the US and joined the laboratory of Raul Andino at UCSF. He has been involved in several projects but here we chat predominantly about his 'Pathogen Control Strategy' to explain why aging evolved.
Peter's Twitter: / lidskypeter
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Timestamps:
Intro - 00:00
Aging as a paradox - 02:30
Theories of aging - 03:45
Pathogen control strategy - 09:30
Advice - 47:00
Please note that The Sheekey Science Show is distinct from Eleanor Sheekey's teaching and research roles at the University of Cambridge. The information provided in this show is not medical advice, nor should it be taken or applied as a replacement for medical advice. The Sheekey Science Show and guests assume no liability for the application of the information discussed.
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He hits the nail on the head with every topic in my opinion.
Hard to understand him.
@wmp3346 yes, this is my bad.. can you help me indicating which parts were unclear?
Wow thank you for information I will search about the red theory hypothesis. It’s so fascinating
Nice touch on Sheekey character opening wink ;-) Please podcast this (&all your other interviews).
Its important to remember that DNA methylation is part of the immune system. Against transposons and retroviruses.
There is clear change in gene expression with time that is coordinated and consistent so that would be aging.
Some coopted mobile genetic elements may be whats implementing these changes. Mobile genes persist in the germline and cannot be selected out of a population. Hence the persistance of aging.
I think the content must be very good. But, it is difficult for me to get the whole idea. Can you summary it in another video?
The comparison between rats and squirrels was interesting as they are both rodents and about the same size. Would a detailed side by side comparison of their DNA show the differences that lead to the age limit differences?
I agree, I was thinking the same
@MasterTBeast rats and squirrels are of similar sizes. About 300 g.
Great example is mouse (3 years max in wild) vs bat (about 40 years max in wild)
And Bats have to fly to eat, higher kinetic energy = higher mortality!
@SladkaPritomnost yes, not sure mortality in bats is higher than in mice
Doesn't the Red Queen Hypothesis kind of explain it? Mice are more social and they spend more time next to their offspring and parents. Squirrels are more solitary = less chance of infecting their offspring.
Dr. Lidsky should take a ride a few miles north of San Francisco and look in awe at the Redwood trees some of which are 3000 years old and some may be as many as 4000 years old. Cancer cells when continuously fed seem to be immortal. Perhaps aging leading to death is a genetic defect that appeared early in the evolution of life. I think it would be far more interesting to investigate the process of aging, its root cause and to engineer means to stop it and reverse it to our healthiest point of devopment and stay there indefinitely. If anyone succeeds it will put actuaries out of business.
To understand the mechanism we need to understand the purpose first.
@Peter Lidsky Why does there have to be a purpose? If there is a purpose of life processes, it's to stay alive.
@@markfischer3626 no - to spread the genes. Aging must be helpful to spread genes somehow.
@Peter Lidsky Life continues long after fertility declines sharply. If that were true they'd die after the male mates and the female gives birth to offspring to the point where they can survive without her.
@RandomGuy-qg9xf 1) but long-lived species are cancer resistant (google Peto's paradox)
2) aging causes ~20% of deaths in the wild. Evolution and turnover would happen anyway.
I think aging probably is adaptive. In a world of scarce resources, it's not efficient to allocate resources to members of the tribe/pack/herd that are no longer reproducing or rearing offspring (the sole "purpose" of any species.) Once the members of a generation have had and reared children to adulthood, they are essentially worthless for the survival and evolution of the species. This is probably why the average lifespan of most of our ancestors was only 30-40 years; just long enough to have and raise children, and then die so that scant resources aren't wasted on them. This theory holds up when looking at longest lived animals, which are typically loners and/or living in nutrient rich environments and/or can go very long periods without food. If resources are plentiful and/or if an animal doesn't need much to survive and reproduce, then there's no reason to kill the parent/grandparent generations off quickly.
@@RandomGuy-qg9xf No, these ideas are fundamentally wrong. Aging is not neutral. Extrinsic mortality does not directly affect the evolution of lifespan.
See e.g. 10.1016/j.tree.2019.02.006
In a world of scarce resources, is it cheaper to make a new animal starting from a zygote or to maintain the parent?
@Random Guy " *our ancestors lived usually longer than that* "
No, not really. Some did, sure. But it wasn't the norm. Even correcting for long lived individuals and infant mortality, the average the bulk of the bell curve sits around 40.
" *Humans possibly evolved to be very long lived because people learned valuable skills and contributed to the survival of the group just with their experiences* "
Hence why don't die immediately after having children, but after raising/teaching them. But it certainly doesn't take 7 decades to impart wisdom essential to survival, and evolution only "cares" about survival and reproduction.
Keeping Grandpa Grok around for 70 years just so he can tell the occasional caveman war story isn't exactly an efficient use of resources from an evolutionary perspective. Talk about diminishing returns.
" *To me it seems, evolution adjusts the lifespan of an animal up to a point of diminishing returns...* "
Right. Which can involve many factors. One of which being the ratio of animals to resources. Doesn't make sense to have animals that live forever in a resource-scarce environment. Hence aging.
" *animals who reach a remote island without predators sometimes evolve very rapidly to reach higher maximum lifespans* "
Sure. The same probably applies to our ancestors as well. In a world of predators, disease, injury, weather, scarce resources etc... it doesn't make sense for humans that don't age to evolve, since they're going to die of something else anyway.
This doesn't counter my theory though; it goes hand in hand with it. It's not as if there's one and only one influence on the evolution of any given trait.
@@peterlidsky4934 Reproduction is non-negotiable. An organism can't evolve if it doesn't reproduce. So it doesn't really matter whether it's more expensive to create a new generation or maintain the current one. Creating new offspring is essential fro evolution to occur and will therefore always take priority. If and when it doesn't, that species will almost inevitably die off.
The exception might be animals that live in extremely safe and resource rich environments, and/or that are extremely resilient. There are a handful of nearly immortal (or even truly immortal) species, but even they still reproduce, because a single organism cannot evolve to adapt to its environment to any significant degree. Only random mutation during reproduction can accomplish that.
@@scottk1525 organism does not need to age to reproduce.