We Don't Know if We See the Same Colors

the colours that we finally think we see are labels used for convenience by the brain. I used to be disappointed when I saw 'false colour' images, say, satellite photographs of earth, or computer-constructed images of deep space. The caption tells us that the colours are arbitrary codes, say, for different types of vegetation, in a satellite picture of Africa. I used to think false colour images were a kind of cheat. I wanted to know what the scene 'really' looked like. I now realize that eve...

 Guppies Evolve Their Spots in Experimentation

Guppies are popular freshwater aquarium fish. As with the pheasants we met in Chapter 3, the males are more brightly coloured than the females, and aquarists have bred them to become even brighter. Endler studied wild guppies (Poecilia reticulata) living in mountain streams in Trinidad, Tobago and Venezuela. He noticed that local populations were strikingly different from each other. In some populations the adult males were rainbow-coloured, almost as bright as those bred in aquarium tanks. H...