How have plants evolved to mimic insects when they don't have vision?

Asked by: Andrew Setchfield, Sheffield

The bee orchid has flowers that look like the females of a particular species of bee. When male bees are tricked into mating with them, they get covered in pollen and spread it from flower to flower. Clever as this seems, the bee orchid is oblivious. It can't see itself or the bee and doesn't have the nervous system needed to appreciate the similarity anyway. Luckily, it doesn't need to.

Evolution isn't steered by individuals. It just throws a lot of spaghetti at the walls and sees what sticks. The ancestor of the bee orchid probably relied on nectar to lure bees, just like other flowers. But then a random mutation happened to make one strain look slightly more inviting to bees than the other flowers. Over time, the flowers that looked most like female bees attracted more pollinators, even when they didn't bother producing much nectar. So they reproduced quicker with less effort. This is a slow process, but with a few million years and enough determined bees, you can get a lot done. Although to be fair, it still only looks vaguely like a bee, so it's a good thing that bees don't have great eyesight either!

Read more:

• Why do bees die when they sting you?
• If bees became extinct, what effect would this have on mankind?

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