The Ecological Energy Pyramid
Lesson notes
Overview
Only about 10% of energy passes to the next trophic level, so top predators are rare. This topic is rated advanced and is number 51 of 110 in Biology. Deeper models, formal results and harder reasoning.
What you are seeing
The panel above shows a bar chart that compares values on one scale, so differences in size are easy to see. The animation is drawn live from the model, so everything you see responds to the sliders. Press Space to pause, use Restart to replay from the start, and change the speed to slow down quick events.
In depth
Only about 10% of the energy at one trophic level passes to the next; the rest is used in respiration, lost as heat or left in waste and uneaten parts. So the energy available falls steeply at each step, and there is a limit of four or five levels in a food chain. It explains why top predators are rare and need large territories, and why eating plants directly supports many more people per hectare than eating meat.
Reading the relationship
The expression "10% rule" is a compact summary of the idea. It uses the symbols r, u, l, e; name what each one stands for before you start. Then use the sliders to see how changing one quantity changes the others.
A guided exploration
1. Run the animation once with the default settings and describe in words what happens. 2. Change one slider at a time and note which quantity responds most. 3. Push each slider to its extreme and decide whether the result still makes sense.
Try this
Try to explain why the pattern holds, not just what it is. Look for limiting cases and what happens at the edges.
Common pitfalls
Biological processes are rarely all-or-nothing. Look for the feedback, the timing and the exceptions, rather than learning a single fixed sequence by heart.
How it connects
It builds on “Food Chains and Webs”, the topic before it in Biology. Once you are comfortable, continue with “The Carbon Cycle”.
Why it matters
Biology shows how living things are built and how they work, grow, inherit traits and adapt.
Where you might use it
- Revising “The Ecological Energy Pyramid” before a class, exam or certification
- Understanding inherited conditions, medicines and how the body responds to disease
- Working in farming, conservation and food production, where populations and genes matter
- Following news about vaccines, genetic testing and climate effects on wildlife
Frequently asked questions
What is The Ecological Energy Pyramid?
Only about 10% of energy passes to the next trophic level, so top predators are rare. It is an advanced topic in Biology.
How do I use the The Ecological Energy Pyramid simulation?
The panel at the top shows a bar chart that compares values on one scale, so differences in size are easy to see. Move the sliders one at a time, then press Space to pause the animation and look closer.
What does the formula mean?
The expression 10% rule packs the idea into symbols. Name each symbol first, then change one quantity with the sliders and see which others respond.
Who is this topic for?
Deeper models, formal results and harder reasoning. If the quiz feels hard, reread the lesson notes and try the previous topic first.
What should I learn before this?
Start with “Food Chains and Webs”, the previous topic in Biology. Each topic in a subject builds on the ones before it.
How do I track my progress?
Press “Mark as learned” on this page. Progress is stored only in this browser and is never sent anywhere. The Browse page can show topics you have learned or still need to learn.