Biological Mimicry

Put on a scary ghost mask at a Halloween party, and people tend to edge away. Wild animals save their lives the same way. The hoverfly has no stinger and no venom at all, yet it flies around in a yellow-and-black striped outfit just like a fearsome honeybee.

Birds remember the painful sting of a bee from the past, so even a similar stripe makes them jump and flee. When a weak, tasty creature with no weapons protects itself by copying a dangerous, venomous look-alike, it is called Batesian mimicry.

There are also hidden masters that turn into objects around them instead of living things. A stick insect makes its body color and even its bumpy joints match a twig perfectly, and hides among the branches. Some moths copy the shape of a dry dead leaf, lie flat on the ground, and slip right past a predator's gaze.

By copying something dangerous or blending into the background, an animal can sharply cut its chances of being eaten when it meets an enemy. That is how even weak, plant-eating insects can live safely in a harsh natural world.

Mimicry does not stop at weak animals copying strong ones. Sometimes strong animals with poison or a foul smell match each other's looks, too. Groups of poisonous butterflies in South America belong to different species, yet they all carry the same orange-and-black wing pattern, as if they had agreed on it.

For a predator, tasting just one orange butterfly and finding it bitter is enough. It will assume all the similar-looking butterflies are poisonous and avoid them. It is a clever method: dangerous creatures share one warning signal, so the sacrifices made while predators are learning stay as small as possible.

On the flip side, some aggressive hunters trick their targets to set an easy dinner table. The orchid mantis spreads its body like a bright pink flower petal and waits quietly. When a butterfly or bee flies in looking for nectar and comes close, thinking it is a flower, the mantis snaps it up in a flash.

Even underwater, an anglerfish wiggles a spine on its forehead like a worm to lure small fish. So mimicry can be a shield for the weak, but it can also be a sharp spear for luring prey and pouncing.

When you watch mimicry, it can look as if an insect thought it over and decided, "I'll dress up like a bee." But no living thing can choose to be born with a different color or shape.

The truth is that, by chance, a mutation in the past produced an individual with a pattern just a little more like a fearsome bee. That individual was attacked a little less by enemies, lived longer, and passed more of its genes on to the next generation.

Over thousands and tens of thousands of generations, this process piled up step by step, until the look became so refined that it was hard to tell from the real thing. So mimicry is not a brilliant acting performance by the animal. It is the result of evolution shaped by natural selection.

In the end, mimicry is one of the most visible and vivid pieces of evidence for the power of evolution, in which traits that help survival win out from random changes.