Chris Kempes

So as organisms evolve and become more complicated, you can get new sorts of constraints. For example, why I already put the brain here And so if I'm going to put an eyeball somewhere, where should I put it? And that's that's a constraint that's related to an evolutionary decision that was made in the past. And we often call those sort of emergent constraints or physiological constraints.

So as organisms evolve and become more complicated, you can get new sorts of constraints. For example, why I already put the brain here And so if I'm going to put an eyeball somewhere, where should I put it? And that's that's a constraint that's related to an evolutionary decision that was made in the past. And we often call those sort of emergent constraints or physiological constraints.

But often when I'm saying physical constraints, I just mean the laws of physics, diffusion, gravity, fluid flow, electricity and magnetism. These are the sorts of things that we're thinking about.

But often when I'm saying physical constraints, I just mean the laws of physics, diffusion, gravity, fluid flow, electricity and magnetism. These are the sorts of things that we're thinking about.

Yeah, that's a great way to put it. And I often like to say that evolution according to physical constraints is sort of the ultimate convergence. It's the thing you can most rely on. It's the thing most likely to happen. And we wrote a paper where we said, you'll get optimization of traits if those traits depend on a very dominant physical constraint.

Yeah, that's a great way to put it. And I often like to say that evolution according to physical constraints is sort of the ultimate convergence. It's the thing you can most rely on. It's the thing most likely to happen. And we wrote a paper where we said, you'll get optimization of traits if those traits depend on a very dominant physical constraint.

And what I mean is, to your point about quantum mechanics, Quantum mechanics certainly apply at the scale of entire trees. They're not a dominant constraint.

And what I mean is, to your point about quantum mechanics, Quantum mechanics certainly apply at the scale of entire trees. They're not a dominant constraint.

So many of the quantum mechanical effects have been averaged out over all of these different particles that I don't really need to use, say, the Heisenberg uncertainty principle to understand what's happening for a vascular plant or a large tree. However, that constraint is still there. But gravity is a dominant constraint.

So many of the quantum mechanical effects have been averaged out over all of these different particles that I don't really need to use, say, the Heisenberg uncertainty principle to understand what's happening for a vascular plant or a large tree. However, that constraint is still there. But gravity is a dominant constraint.

And so if traits are connected to a dominant physical constraint, evolution will be able to see that and we'll get traits that look optimized according to those physics. And then those traits have to be independent enough of other traits. So there are many cases in biology where you would like to optimize something, but you can't for other reasons.

And so if traits are connected to a dominant physical constraint, evolution will be able to see that and we'll get traits that look optimized according to those physics. And then those traits have to be independent enough of other traits. So there are many cases in biology where you would like to optimize something, but you can't for other reasons.

So a great example is our optic nerve that connects our eyeball to our brain is longer than it should be. And many people have talked about this optic nerve seems much longer than you would want in some optimal case. And part of that is likely due to the fact that you had brain structure and you develop this eye. And then it's really hard to remodel the brain.

So a great example is our optic nerve that connects our eyeball to our brain is longer than it should be. And many people have talked about this optic nerve seems much longer than you would want in some optimal case. And part of that is likely due to the fact that you had brain structure and you develop this eye. And then it's really hard to remodel the brain.

It's really hard to move around different modules of the brain. And so you deal with a slightly longer optical nerve because it's just too hard to change everything else. And so that's what we mean by traits have to be independent enough of other traits in order for these physical constraints to be something that evolution can see.

It's really hard to move around different modules of the brain. And so you deal with a slightly longer optical nerve because it's just too hard to change everything else. And so that's what we mean by traits have to be independent enough of other traits in order for these physical constraints to be something that evolution can see.

Exactly. Yeah, exactly. And so what we often – in that same language, what we would say about some of these physical constraints is they create these huge valleys that are impossible to miss. Yeah, good. And so even though there's roughness on the surface, it's really like a –

Exactly. Yeah, exactly. And so what we often – in that same language, what we would say about some of these physical constraints is they create these huge valleys that are impossible to miss. Yeah, good. And so even though there's roughness on the surface, it's really like a –

gently undulating grassy hill that is all part of one big valley, one big watershed, where everything rolls to the bottom. And that's just because the physics is so strong, the physical constraints are so strong, you can't help but wind up in the bottom of the valley. But there could be emergent constraints that create local valleys that you can't get out of, as you were mentioning, and so forth.

gently undulating grassy hill that is all part of one big valley, one big watershed, where everything rolls to the bottom. And that's just because the physics is so strong, the physical constraints are so strong, you can't help but wind up in the bottom of the valley. But there could be emergent constraints that create local valleys that you can't get out of, as you were mentioning, and so forth.