<Ul> <Li> Origin of life </Li> <Li> History of life </Li> <Li> Timeline of evolution </Li> <Li> Human evolution </Li> <Li> Phylogeny </Li> <Li> Biodiversity </Li> <Li> Biogeography </Li> <Li> Classification </Li> <Li> Evolutionary taxonomy </Li> <Li> Cladistics </Li> <Li> Transitional fossil </Li> <Li> Extinction event </Li> </Ul> <Li> Origin of life </Li> <Li> History of life </Li> <Li> Timeline of evolution </Li>

Which of the following is essential for a trait to be an adaptation