Chapmans bring their weird science to Tate

Gallery: See more pictures of When Humans Walked The Earth here

Entitled When Humans Walked The Earth, the sculpture, loaded with sexual references, is inspired by their 1993 work Little Death Machine which is in the Tate's collection. Elements of that work, including a brain, milk bottles and tools, are reproduced in bronze to create a series of "impossible" machines.

Jake and Dinos Chapman - who were nominated for a Turner Prize in 2003 - created the sculpture to coincide with a retrospective of their work currently being held at Tate Liverpool. A Tate Britain spokeswoman said When Humans Walked The Earth was rich with artistic and philosophical meaning.

She said: "The machines emulate biological and psychological states such as breathing, thinking, copulation and death - contesting the distinctions we make between man and machine and assumptions about historical progress.

"When Humans Walked The Earth 2007 questions mechanistic theories of the human mind - notably those of the pioneering psychoanalyst Sigmund Freud - and also makes reference to Dada and Surrealism's ability to transform everyday objects into something that challenges conventional perception."

In an interview to mark the Tate Liverpool retrospective, the brothers said their bronze machines had a life of their own: "Even though they're made of bronze we like to think they have congealed or crystallised into possibility for reasons beyond our control... in a manner that thoroughly refuses any form of possessive control we might make over them even if we were stupid self-satisfied artists."

When Humans Walked The Earth is at Tate Britain from tomorrow until 10 June. For more information visit www.tate.org.uk/britain