Chris Kempes

Things diversify and go in every direction and you get lots of new solutions. But you have to wait for that chance event to get you over the hump still.

Things diversify and go in every direction and you get lots of new solutions. But you have to wait for that chance event to get you over the hump still.

Exactly. And I think one of the reasons for that is once you move into this new space, you see a bunch of new challenges that you never had to deal with before. And likely each of those challenges needs its own solution. And so it's not then surprising that you get a bunch of complexity all at once.

Exactly. And I think one of the reasons for that is once you move into this new space, you see a bunch of new challenges that you never had to deal with before. And likely each of those challenges needs its own solution. And so it's not then surprising that you get a bunch of complexity all at once.

And maybe you don't get it all at once evolutionarily, but looking back from our current vantage of all of these well-adapted organisms a billion years later, we would say, oh, wow, there's many innovations. They're all really optimized and they all go together. Now, you know, one of the biggest debates in how eukaryotes came to be is the ordering of events.

And maybe you don't get it all at once evolutionarily, but looking back from our current vantage of all of these well-adapted organisms a billion years later, we would say, oh, wow, there's many innovations. They're all really optimized and they all go together. Now, you know, one of the biggest debates in how eukaryotes came to be is the ordering of events.

I mean, it's countless papers written about what was first. I mean, it's even gotten to the point where we say, well, is that a mitochondria first? Yeah. Is that a phagocytosis first argument? And so people really are trying to work through the ordering and have big debates about the ordering. And we don't have any fossils to tell us because these things are goopy and don't preserve well.

I mean, it's countless papers written about what was first. I mean, it's even gotten to the point where we say, well, is that a mitochondria first? Yeah. Is that a phagocytosis first argument? And so people really are trying to work through the ordering and have big debates about the ordering. And we don't have any fossils to tell us because these things are goopy and don't preserve well.

And so whereas that debate gets resolved in dinosaurs about what happened first, it doesn't get resolved for the eukaryotes yet.

And so whereas that debate gets resolved in dinosaurs about what happened first, it doesn't get resolved for the eukaryotes yet.

Exactly. Yeah. So one thing that we found was the way in which protein concentration scales with cell volume is preserved from bacteria into eukaryotes. And we think there's one optimization related to diffusion that really drives that uniformity in this one scaling relationship. And However, metabolic power scaling shifts between prokaryotes and eukaryotes. The growth rate scaling shifts.

Exactly. Yeah. So one thing that we found was the way in which protein concentration scales with cell volume is preserved from bacteria into eukaryotes. And we think there's one optimization related to diffusion that really drives that uniformity in this one scaling relationship. And However, metabolic power scaling shifts between prokaryotes and eukaryotes. The growth rate scaling shifts.

The eukaryotes pick up a bunch of scalings that you obviously don't have in bacteria, like how many mitochondria they have. Jordan Oki has a really wonderful paper showing how many mitochondria you get as a function of cell volume. And so there's, you know, lots of things are changing and then some things are staying the same. And

The eukaryotes pick up a bunch of scalings that you obviously don't have in bacteria, like how many mitochondria they have. Jordan Oki has a really wonderful paper showing how many mitochondria you get as a function of cell volume. And so there's, you know, lots of things are changing and then some things are staying the same. And

And both of those angles help us understand if we're onto the right theory, if we're onto the right constraints. So, for example, if we think a dominant constraint comes with a limit that should imply a major shift at one scale and we look at prokaryotes on one side and eukaryotes on the other side and they have exactly the same scaling, then we were wrong about the constraint.

And both of those angles help us understand if we're onto the right theory, if we're onto the right constraints. So, for example, if we think a dominant constraint comes with a limit that should imply a major shift at one scale and we look at prokaryotes on one side and eukaryotes on the other side and they have exactly the same scaling, then we were wrong about the constraint.

Luckily, that hasn't happened to us. But that's a nice way to say we could easily falsify our theory if we'd pick the wrong constraints because there are certain things we would predict that just wouldn't hold up. You would move across transitions and either see shifts that you didn't expect or not see shifts that you did expect. And we think that's a sort of secondary test of these theories.

Luckily, that hasn't happened to us. But that's a nice way to say we could easily falsify our theory if we'd pick the wrong constraints because there are certain things we would predict that just wouldn't hold up. You would move across transitions and either see shifts that you didn't expect or not see shifts that you did expect. And we think that's a sort of secondary test of these theories.

Yeah, that's great. So what I mean by metabolic power is just the total energy available to a cell. So this is how it would be like the total food that you and I ate. For cells, it's the same. If they use sunlight, it's the total sunlight they're able to capture. If they eat other things, it's how much of that that they're able to eat per unit time.

Yeah, that's great. So what I mean by metabolic power is just the total energy available to a cell. So this is how it would be like the total food that you and I ate. For cells, it's the same. If they use sunlight, it's the total sunlight they're able to capture. If they eat other things, it's how much of that that they're able to eat per unit time.