The Logic of Living Systems
Explore the physical constraints, chemical engines, and evolutionary tradeoffs that dictate how living things are built. Move beyond rote diagrams to understand why biological designs look, scale, and function the way they do.
Like Duolingo, but for The Logic of Living Systems. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 12 levels across 2 sections, about 24 minutes end to end, roughly 5 days at five minutes a day. It moves through Physical and Chemical Constraints and Evolutionary Economics and Tradeoffs. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in The Logic of Living Systems
- As an organism grows, its volume scales with the cube of length while its surface area scales only with the square
- A large body's volume demands far more gas and nutrient exchange than flat exterior skin can provide
- Internal folding, like lung alveoli and intestinal villi, packs massive surface area into a compact volume
- Whole-body metabolic rate scales to body mass raised to the 3/4 power rather than directly 1:1
- Mass-specific metabolic rate drops as body mass rises, so larger animals burn far less energy per gram of tissue
- Shrews and mice must feed almost constantly to fuel their intense, high-turnover cellular respiration
- Heat generation depends on body volume, whereas heat exchange with air occurs entirely across surface area
- Bergmann's rule states colder climates favor bulkier, compact bodies to minimize heat-shedding surface area
- Allen's rule states desert and tropical endotherms evolve longer, thinner limbs and ears to shed heat
- Fractal vascular branching fills three-dimensional tissue volume while minimizing total hydrodynamic resistance
- Repeated branching causes total vessel cross-sectional area to surge, slowing flow to allow diffusion
- Capillary networks maximize interface contact without requiring excessive fluid volume or cardiac pumping work
- An animal's gravitational mass scales with volume (length cubed), putting immense load on the skeleton
- Bone weight-bearing strength scales strictly with cross-sectional area (length squared), lagging behind mass
- Giant terrestrial animals must evolve disproportionately thick, column-like legs to avoid bone buckling
- Sodium-potassium pumps consume roughly 20 to 50 percent of a resting cell's basal ATP budget.
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives The Logic of Living Systems the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
When a living creature doubles in length, what happens to its dimensions?
Get it right to open this lesson and 11 more in the app.
How to learn The Logic of Living Systems, step by step
Go in order. 12 short levels across 2 sections, about 24 minutes in all, five minutes a day.
- 1
Physical and Chemical Constraints
- Scaling Laws and the Geometry of Bodies
- The Cell's Electrochemical Engine
- 2
Evolutionary Economics and Tradeoffs
- Energy Budgets and Life History Decisions
- Evolutionary Constraints and Biological Kludges
2 sections · 4 units · 12 levels. Built to play, not to enroll.
Questions about The Logic of Living Systems
How do I learn The Logic of Living Systems?
Go in order: start with Physical and Chemical Constraints, then Evolutionary Economics and Tradeoffs. On Tomo that's 12 short levels, about 24 minutes in all, played five minutes a day. Start free and play the first level in under a minute.
Is there a Duolingo-style app for The Logic of Living Systems?
Yes. Tomo works like Duolingo: short daily lessons, streaks and quick quizzes. The Logic of Living Systems is one of its free courses, and you can type any other topic to get a course of your own.
Is The Logic of Living Systems free?
Yes. The Logic of Living Systems is playable on Tomo's free plan, which doesn't expire. No credit card, no waitlist. Download the app and start your first lesson.
How long does it take to learn The Logic of Living Systems?
12 levels across 2 sections, about 24 minutes of play in total. It's built for five minutes a day, so you finish it a little at a time instead of all at once.
Do I need any background to start The Logic of Living Systems?
No. It's pitched at an intermediate level, so it starts where you are and builds up. If you can tap a phone, you can start.
Tomo is in ChatGPT
Tomo is also a ChatGPT plugin: the same playable courses, built and played inside your chat.
Add Tomo to ChatGPT- What to ask
- “Make me a Tomo course on black holes.” “Turn this chat into a Tomo course.”
- What you get
- Quick questions with instant feedback, hearts and stars, ready to play in about a minute.
- Where it goes
- No sign-up to start. Connect your Tomo account and your streak carries on in the app.
You pick the voice
The Logic of Living Systems is taught in the Bestie style: your friend who just gets it. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start The Logic of Living Systems today.
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