Apostatic selection facts for kids

Apostatic selection is a special type of natural selection. It happens when predators hunt for prey that come in different looks or forms. Imagine a group of animals where some are spotted and some are striped. If the spotted ones are much more common, predators might learn to look for and catch mostly the spotted ones.

This idea is similar to "prey switching." But apostatic selection is used when the different forms of prey are from the same species and are genetic variations. "Prey switching" is used when a predator changes its diet between completely different species.

When predators focus on the most common form of prey, it gives an advantage to the less common forms. This means the rare forms have a better chance to survive and reproduce. This helps to keep a balance in the population, so neither form becomes too rare or too common. It's like a natural balancing act!

How it Works

Apostatic selection happens because predators often form a "search image" in their minds. This means they learn to recognize and look for the most common type of prey.

The Predator's Search Image

When a predator, like a bird, is hunting for insects, it might learn what the most common insect looks like. For example, if most insects are green, the bird will get really good at spotting green insects. This makes it harder for the green insects to hide.

Advantage for Rare Prey

Because the predator is focused on the common form, the rare forms are often overlooked. They don't fit the "search image" the predator has in its mind. This gives the rare forms a better chance to survive and pass on their genes.

Keeping a Balance

As the rare forms survive and reproduce, their numbers might start to grow. If they become too common, then the predators might start to form a new search image for them. This process helps to keep the different forms of prey in a kind of balance. It prevents one form from completely disappearing or taking over the whole population.

Examples in Nature

This type of selection can be seen in many animals.

• Snails: Some snails have shells with different colors or patterns. Birds that eat snails might learn to spot the most common shell type, giving the rarer types a better chance.
• Insects: Many insects have different color forms. If a certain color is rare, it might be safer from predators who are used to hunting the more common colors.

Images for kids

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  Blue tit searches for insect prey using a search image, leaving scarcer types of prey untouched.

See also

In Spanish: Selección apostática para niños