Explore 10 curated biology facts on ScienceCards. Discover surprising, well-sourced science one card at a time.
Sharks (450 million years old) have existed for two… — Sharks (450 million years old) have existed for two galactic years—our solar system has orbited the Milky Way twice since they appeared. They predate dinosaurs and are older than trees.
Electric eels have 6,000 electrocytes—muscle cells that… — Electric eels have 6,000 electrocytes—muscle cells that produce voltage—stacked in series, generating 860 volts. Enough to stun a horse. Volta copied this design in 1799, inventing the first battery.
After 30-40 minutes in darkness, your eye's rod cells can… — After 30-40 minutes in darkness, your eye's rod cells can detect individual photons—the smallest unit of light. Your eye operates at the theoretical limit; it cannot get more sensitive.
Every breath you take is thanks to bacterial waste. — Every breath you take is thanks to bacterial waste. Cyanobacteria spent a billion years releasing oxygen as a toxic byproduct. The Great Oxygenation Event killed most early life—survivors adapted.
An octopus has ~180 million neurons in its brain and 320… — An octopus has ~180 million neurons in its brain and 320 million in its arms, which think semi-independently. They use tools, solve puzzles, recognize faces, learn by observation, and play.
Origin-of-life research studies the most mysterious… — Origin-of-life research studies the most mysterious transition in Earth's history: from chemistry to biology. Around 4.2 billion years ago, molecules became life—and we still don't know how.
Sea turtles navigate thousands of miles using Earth's… — Sea turtles navigate thousands of miles using Earth's magnetic field as a biological GPS. They detect both intensity and angle—hatchlings reorient instantly when researchers shift the field.
3,000-year-old honey found in Egyptian tombs is still… — 3,000-year-old honey found in Egyptian tombs is still edible because honey’s low water, acidic pH (~3.2–4.5), and glucose oxidase enzyme produce antimicrobial hydrogen peroxide, preventing spoilage.