In the late 1840s, a British naturalist named Henry Walter Bates set out on an 11-year expedition into the Amazon jungle. When he returned to England in 1859, he had a collection of over 14,000 rare and new species of insects, never before discovered by science.
At the time, many other naturalists were doing the same thing. What set him apart was that he also studied and observed their behavior and went in-depth into their relationships and how they interacted with one another. For Bates, this was a way to understand each species' different roles within an ecosystem.
At one point in his expedition, he noticed that the "Ithomiini" butterfly - a slow-flying and extremely abundant species - was hardly ever hunted by predators. "Oh, maybe they taste terrible!" he thought and decided to gather specimens to examine them more closely.
He soon discovered that there was another type of butterfly species living amongst the Ithomiinis that he caught. They were of two different families, yet their body shape, wings, and appearance were nearly identical. This newfound discovery left him puzzled, yet he observed that this was a common occurrence throughout the Amazon Rainforest. What's more, it was not exclusive to butterflies, but hundreds of different insects and animals replicated this behavior.
Of the two families, he found that the Ithomiini was ignored by predators, while the lookalike was regularly targeted - despite it being the faster of the two. Bates concluded that the lookalike had evolved to mimic the Ithomiini to confuse predators, essentially allowing them to hide in plain sight.
This phenomenon is now known as Batesian mimicry, where a weaker or disadvantaged species would mimic the appearance of a stronger species to increase its chances of survival.
Batesian mimicry is a natural and unconscious evolutionary process. If an animal changes itself consciously, then it is no longer Mimicry. It can include appearance, sounds, and even behaviors, and there are endless examples across the insect and animal world.
Batesian mimicry is also different from camouflage, where an animal actively hides to blend in with his environment. In Mimicry, species want or mean to be detected, and the goal is to confuse predators. The size of the “model” population is also crucial - when there are more models, it is easier for the mimics to imitate.
In a nutshell, Mimicry, as a phenomenon, is an incredibly complex, nuanced, and exciting field of natural science. Over the years, more types of mimicry have been observed and recognized, such as Mullerian mimicry, Defensive mimicry, and even aggressive mimicry - all with their unique criteria.
Mimicry is considered significant proof of Darwin's Theory of Evolution. In fact, he included Batesian mimicry in his then-controversial book. Batesian mimicry allows us to witness first-hand the effects and outcomes of natural selection. It offers a deeper understanding of evolution, which can help us ponder how it applies to our human species.