Look down a microscope at soil or seawater and you’re likely to see many different shapes for certain groups of organisms. Could each unique structure be an adaptation to the environment? Or is this diversity simply due to random factors? After studying slime moulds for decades, evolutionary biologist John Bonner has come to the conclusion that the rules of evolution work differently for small organisms.

Alison George shows us examples of the variety in nature’s tiny designs.

Read more: “Rules of evolution go a bit random if you’re small“