Remove a species from an ecosystem and other species tend to suffer. Take the giant Madagascar tortoise, for example. The two species of giant tortoises on Madagascar went extinct centuries ago, but their loss is still being felt today.
Botanists have long puzzled over a peculiarity of ancient plants called cycads: they have huge, bright, fleshy seeds displayed in enormous cones.
Bonobo poop matters. Well, maybe not the poop itself, but what's in it. You see, bonobos eat a lot of fruit, and fruit contains seeds. Those seeds travel through a bonobo's digestive system while the bonobo itself travels through the landscape.