Almost any way you look at them, arthropods are successful:
- They have been around for more than 500 million years and are still evolving.
- They live on Earth in overwhelming numbers.
- They have come in all shapes and sizes.
- They have evolved to fill a variety of ecological niches — from tiny internal parasite to giant bird-eating predator.
But what is it about arthropods that has made them so successful? Let’s begin our investigation by reviewing what an arthropod is.