There is a category of biological feature that only makes sense as a leftover, and the third molars are the most familiar example.
They appear late, typically in the late…
Almost nothing in the animal world does what this does.
A great many animals signal. They warn, threaten, court and call, and the signal refers to the here and now…
Almost everybody has experienced this, and almost nobody has considered how strange it is.
Sitting still in a vehicle, entirely uninjured, having eaten nothing unusual, a person becomes progressively unwell…
Blood Types Were Discovered Over a Century Ago and Nobody Has Established What They Are Actually For
Most people know their blood type, treat it as a fixed personal fact like eye colour, and have never wondered what it is.
It is a molecule. Specifically, blood type…
The recurring problem is the same everywhere: sleep appears to be necessary, and being asleep is dangerous. Almost every solution below is a compromise between those two facts. Here are…
Animal navigation combines several systems at once, which is why removing one rarely stops an animal entirely. Here are seventeen of the tools involved.
1. Reading the Earth's Magnetic Field…