Venki Ramakrishnan

If you're a mouse, there's no point in spending a lot of resources to repair and maintenance because we do have sophisticated repair and maintenance mechanisms. Otherwise, we wouldn't even last a year. We would be dead before that. We do have this very sophisticated mechanism, but that takes energy and takes resources.

If you're a mouse, there's no point in spending a lot of resources to repair and maintenance because we do have sophisticated repair and maintenance mechanisms. Otherwise, we wouldn't even last a year. We would be dead before that. We do have this very sophisticated mechanism, but that takes energy and takes resources.

And in a small animal, it's not worth it because the animal is going to be killed off by a predator or die of starvation or some other cause. So there it's more advantageous for evolution to put resources into rapid growth and reproduction. And that's what a mouse does. And at the other end, you have things like a bowhead whale or a Greenland shark, very slow metabolism and

And in a small animal, it's not worth it because the animal is going to be killed off by a predator or die of starvation or some other cause. So there it's more advantageous for evolution to put resources into rapid growth and reproduction. And that's what a mouse does. And at the other end, you have things like a bowhead whale or a Greenland shark, very slow metabolism and

well, especially the Greenland shark has a very slow metabolism, large, and can produce offspring over a long period. So you have these opposite extremes. And the interesting twist on this are bats. So bats weigh about the same as a mouse, the same size as a mouse, but can live 10 to 20 times as long. And the reason is bats can fly, so they can escape predation.

well, especially the Greenland shark has a very slow metabolism, large, and can produce offspring over a long period. So you have these opposite extremes. And the interesting twist on this are bats. So bats weigh about the same as a mouse, the same size as a mouse, but can live 10 to 20 times as long. And the reason is bats can fly, so they can escape predation.

And they also can forage over a much wider area and are less likely to starve. So it makes perfect sense that you would have this evolutionary thing.

And they also can forage over a much wider area and are less likely to starve. So it makes perfect sense that you would have this evolutionary thing.

This is called Pitot's paradox, after Pitot, who was the scientist who first formulated it. Because an animal like a whale or an elephant has thousands of times more cells than a mouse.

This is called Pitot's paradox, after Pitot, who was the scientist who first formulated it. Because an animal like a whale or an elephant has thousands of times more cells than a mouse.

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.