The Historical Food Economy Tracker

The pitch

Forget “biggest,” “scariest,” or “most calories eaten.” Rank species the way an economist would: by what it cost to make them, and how much of the ecosystem’s energy they got to keep. That’s the Historical Food Economy Tracker (HFET) — ten landmark species, four historical epochs, three metrics, one uncomfortable conclusion about where we sit on the chart.

The three metrics

Trophic Production Cost (TPC) — how many plant calories it takes to make one calorie of the target species:

TPC = 10^(trophic_level - 1)

A trophic level 4.5 apex predator has a TPC of ~3,162 — it took 3,162 calories of sunlight-fixed plant matter, filtered up through several tiers of eating and being eaten, to produce one calorie of predator. That’s the real price of being an apex predator, and it’s why they’re rare: the economy can’t afford many of them.

Energetic Return on Investment (eROI) — calories captured per hunt divided by calories spent catching it. A cost side, not a market-share side — not modeled numerically here, but it’s the reason a lion can’t just “decide” to hunt more.

Market Share (Ecosystem Energy Control) — the % of a local ecosystem’s total energy throughput one species alone controls. This is the metric that breaks when you get to the last row of the dataset.

Plot A — King of the Hill: the longevity timeline

Sorted by how long each species actually held its position, on a log scale because the range is enormous — 20 million years for Anomalocaris down to 12,000 years for the modern human food economy. Read that bar at the bottom again: it’s not a typo. Anatomically modern humans have run the current arrangement — agriculture, domestication, industrial food systems — for a rounding error of geological time, and already claim ~40% of the chart’s energy control. Nothing else on this list got that much that fast.

Plot B — Where We Are Today: the trophic map

Every other species on this chart earns ecosystem control by climbing the trophic ladder — Orca at trophic level 5.0 controls about 3%. Modern Homo sapiens sits at trophic level 2.21 (a real published estimate — Bonhommeau et al., 2013 — putting humans nutritionally closer to a pig or an anchovy than to a wolf) while controlling an estimated 40% of ecosystem energy throughput. That combination — low trophic level, total control — doesn’t exist anywhere else on the historical record. It’s not that humans out-hunted T. rex. It’s that agriculture made hunting optional.

Graphic 3 — The “Milkshake” Flow

The classic 10% rule: every tier up the pyramid keeps roughly a tenth of the energy below it, lost to metabolism, movement, and heat. Apex predators pay for their trophic level in compounding 90% losses. Agriculture is humanity’s workaround — a straw stuck directly into the producer tier, skipping three tiers of loss instead of climbing them. We didn’t out-compete the apex predators. We changed which pyramid we’re standing on.

The dataset and the script

Ten species — Anomalocaris, T. rex, Megalodon, Smilodon, Homo erectus, Pleistocene and modern Homo sapiens, African elephant, blue whale, orca — each with an epoch, an era duration, a trophic level, and an estimated ecosystem control %. TPC is computed programmatically from trophic level, not hand-entered. The values are illustrative synthetic estimates (this is a thought experiment, not a peer-reviewed dataset) except the modern-human trophic level of 2.21, which is a real figure from published research.

Full script, reproducible with pandas + matplotlib: scripts/food_economy_tracker.py

python3 scripts/food_economy_tracker.py
# writes hfet-timeline.png, hfet-trophic-map.png, hfet-flow.png
# to static/images/brain/