CSH Workshop
Trade-offs between thermodynamic cost, intelligence and fitness in living organisms
11th-12th March 2024
slides available at: slides.com/jankorbel
Welcome!
About the workshop
1) At the scale of an individual organism (be it a unicellular creature, a single cell in a multicellular organism, or an individual in a eusocial species), what are the inherent physical constraints relating to thermodynamic efficiency, fitness, and intelligence?
2) At the scale of natural selection, how should the theorems of evolutionary biology be modified to account for the trade-off between the thermodynamic costs of performing computation and the fitness benefits of computations?
Two main questions
How do we answer them?
- Participants will give talks related to the main questions
- We will have a discussion after each talk
- We can also use the breaks for discussions
- At the end of the workshop, we will have a round table session
Recommended reading
https://www.dropbox.com/scl/fo/t2089fl9prh12m2c23yw1/h?rlkey=80pai6ifgkhu1qi8b3vuksh1b&dl=0
General rules for talks
- Each talk will be around 30 minutes followed by a discussion
- We will have a discussion after each talk
- If you have any questions, please ask immediately
- Since the participants have different scientific backgrounds, let's try to be not too technical but rather focus on the big picture
Workshop schedule
Monday
9:00 – 9:30 Registration
9:30 – 10:00 Welcome
10:00 – 10:30 David Wolpert
10:50 – 11:10 Coffee break
11:10 – 11:40 Valentin Riedl
12:00 – 14:00 Lunch Break
14:00 – 14:30 Edgar Roldán
14:50 – 15:05 Coffee Break
15:05 – 15:35 Robert Foley
15:55 – 16:25 Tom Ouldridge
Tuesday
9:00 – 9:30 Coffee
9:30 – 10:00 Sosuke Ito
10:20 – 10:40 Coffee break
10:40 – 11:10 Gonzalo Manzano
11:30 – 12:00 Peter Stadler
12:20 – 14:00 Lunch break
14:00 – 14:30 Chris Kempes
14:50 – 15:05 Coffee break
15:05 – 15:35 Riccardo Rao
15:55 – 17:00 Round table
Brief introduction
Can every participant briefly introduce themself?
Please mention briefly:
- Your scientific background
- What are you currently working on?
- Why are you interested in the workshop topic?
Why do we think using a physics theory (stochastic thermodynamics) in biology can be useful?
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Energetics is a crucial aspect of all living systems
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All living organisms must be efficient in energy consumption
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All organisms are, by definition, far from thermodynamic equilibrium
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Novel results in non-equilibrium physics can be useful in understanding the energetics of living organisms and their evolution
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There are many similarities between physical and biological systems
Similarities
Evolution equations
- Deterministic equations (ordinary/partial differential equations)
-
Probabilistic equations Markov dynamics (no memory)
- Master equation
- Fokker-Planck equation (diffusion)
Differences
Conservation laws
- Physical systems - global conservation (global energy)
- Evolutionary systems - local conservation (no single global "potential", typically a set of local "potentials")
The simplest model of a living system
metabolism
nutrients
energy
ATP
chemical reaction network
energy \(E_n\)
# particles \(N_n\)
evolution
genotype
phenotype
fitness function \(\Psi_n\)
environment
production of DNA,
proteins
ATP synthase
...
Importance of ST in living systems
Entropy production - the arrow of time
$$\Sigma = D_{KL}(P(x(t))||\tilde{P}(\tilde{x}(t))) $$
- \(D_{KL}(p\|q) = \sum_i p_i \log \frac{p_i}{q_i}\) is the Kullback-Leibler divergence
- \(P(x(t))\) is the probability of forward trajectory
- \(\tilde{P}(\tilde{x}(t))\) is the probability of backward trajectory
EP is the measure of the time irreversibility of a system
Many results of non-equilibrium thermodynamics remain valid also for non-physical systems
\( \frac{P(\Sigma_t = A)}{\tilde{P}(\Sigma_t= -A)} = e^{At} \)
FT's
\(\frac{Var(J_t)}{E(J_t)^2} \geq \frac{2}{\Sigma_t}\)
TUR's
\(\frac{L(p(t),p(0))}{2 \Sigma_t \bar{A}_t} \leq t\)
SLT's
Two recent papers
