Venki Ramakrishnan

and so if even one of those cells became cancerous and triggered a cancer then the animal would die so you would think those animals would be more likely to get cancer instead it's a mouse that's more likely to get cancer that has to do with the fact that you know all these repair mechanisms don't work as well in a mouse because evolution doesn't care how long a mouse that a mouse should live that long

and so if even one of those cells became cancerous and triggered a cancer then the animal would die so you would think those animals would be more likely to get cancer instead it's a mouse that's more likely to get cancer that has to do with the fact that you know all these repair mechanisms don't work as well in a mouse because evolution doesn't care how long a mouse that a mouse should live that long

But anyway, so it turns out that there's a DNA response repair mechanism. One of the genes involved is called P53 or TP53. And this is involved in sensing DNA damage and triggering repair mechanisms. And it turns out that elephants have something like 20 copies of this gene.

But anyway, so it turns out that there's a DNA response repair mechanism. One of the genes involved is called P53 or TP53. And this is involved in sensing DNA damage and triggering repair mechanisms. And it turns out that elephants have something like 20 copies of this gene.

So they're much more efficient at detecting cells where there's been some problem with the DNA and destroying them so they don't become cancerous. And people have looked at whales, and whales also seem to have alternative repair pathways that presumably prevent them from getting cancer. That is the way that evolution has dealt with the cancer problem.

So they're much more efficient at detecting cells where there's been some problem with the DNA and destroying them so they don't become cancerous. And people have looked at whales, and whales also seem to have alternative repair pathways that presumably prevent them from getting cancer. That is the way that evolution has dealt with the cancer problem.

And yeah, that's right. It's not exactly a cure, but it does give you some understanding. And it also shows you the relationship between aging and cancer. It turns out many of the... things that cause aging, like telomere shortening, these are the ends of our chromosome, get a little shorter each time the cell divides.

And yeah, that's right. It's not exactly a cure, but it does give you some understanding. And it also shows you the relationship between aging and cancer. It turns out many of the... things that cause aging, like telomere shortening, these are the ends of our chromosome, get a little shorter each time the cell divides.

And when they reach a critical stage, the cell stops dividing and goes into a state called senescence, and then it's eventually destroyed. And you would ask, why would it do that? Why not? And if you were to let cells have the ability to proliferate indefinitely, then if that cell became cancerous, it would be a cancer risk.

And when they reach a critical stage, the cell stops dividing and goes into a state called senescence, and then it's eventually destroyed. And you would ask, why would it do that? Why not? And if you were to let cells have the ability to proliferate indefinitely, then if that cell became cancerous, it would be a cancer risk.

And so this idea that you destroy that ability to divide forever in most of our cells and restrict it to just a few cells, like our stem cells, that's probably evolved as a cancer prevention mechanism. And that, again, is because you don't want to get cancer before you have a chance to reproduce.

And so this idea that you destroy that ability to divide forever in most of our cells and restrict it to just a few cells, like our stem cells, that's probably evolved as a cancer prevention mechanism. And that, again, is because you don't want to get cancer before you have a chance to reproduce.

And once you've reproduced, okay, the consequences that you age, that's okay because you've passed on your genes. That's the evolutionary game.

And once you've reproduced, okay, the consequences that you age, that's okay because you've passed on your genes. That's the evolutionary game.

No, there are many different aspects to aging, and they happen from the molecular level all the way to the level of tissues where cells talk to each other. So just to give you an example, we could start with DNA. which encodes proteins and so on. And DNA damage is one of the primary causes of aging. And of course, we have extensive repair mechanisms, but the DNA repair mechanisms themselves

No, there are many different aspects to aging, and they happen from the molecular level all the way to the level of tissues where cells talk to each other. So just to give you an example, we could start with DNA. which encodes proteins and so on. And DNA damage is one of the primary causes of aging. And of course, we have extensive repair mechanisms, but the DNA repair mechanisms themselves

can break down with aging. So it's a kind of auto catalytic or accelerating phenomenon that DNA damage becomes increasing with age. But that's a cause of aging. And then the proteins that are made using genetic information They often, the quality of those proteins goes down with age. Our ability to recycle proteins that are defective also goes down with age.

can break down with aging. So it's a kind of auto catalytic or accelerating phenomenon that DNA damage becomes increasing with age. But that's a cause of aging. And then the proteins that are made using genetic information They often, the quality of those proteins goes down with age. Our ability to recycle proteins that are defective also goes down with age.

So there's all those levels at what I call the protein level. And then this also affects organelles like our mitochondria, which are our organelles in our cell that are responsible for energy production. Of course, some of you may be interested that mitochondria actually were bacteria that were swallowed up by an ancestral cell of ours.

So there's all those levels at what I call the protein level. And then this also affects organelles like our mitochondria, which are our organelles in our cell that are responsible for energy production. Of course, some of you may be interested that mitochondria actually were bacteria that were swallowed up by an ancestral cell of ours.