Marketers and consumers – we’re talking about humans, right? Wrong. Many plants depend on successful marketing for aspects of reproduction, including seed dispersal. And many seed-dispersing animals are discerning consumers of fruit. But some animals are freeloaders. They consume fruit without any benefit to the plant. How can plants attract the dispersers but avoid the scroungers? By Anna Mouton
Seeing the fruit for the trees
Plants need animals to consume ripe fruit that contain fully developed seeds. The green colour of unripe fruit helps to hide them by minimising contrast with green foliage. Ripe fruit changes colour to signal tastiness – a claim backed up by other changes in the fruit such as increased sweetness. This is probably why humans associate redness with sweetness.
Colour is an effective way in which plants can advertise their fruit, but it has to be matched to the colour vision of the target consumer. All colours are not equal in all eyes.
Colour perception results from the detection of different wavelengths of light by photoreceptors in the eye. The brain combines inputs from the photoreceptors to create the experience of colour. Animals have different types of photoreceptors that dictate the range of colours they can see.Read More