We've lost some parts of our natural world. Swathes of plants and animals have been consumed by evolution, shifting climates or the often-damaging expansion of humankind.
For a moment, though, London's iconic Barbican Centre will let you smell a fragment of our lost history. In the corner of a new AI exhibit, a cuboid hood dangles from the ceiling. Inside are four nozzles that slowly release carefully chosen fragrances into the air around you.
The artificial blend is, for now, our best guess at what Hibiscadelphus wilderianus, a tree that once stood on the Hawaiian island of Maui, used to smell like.