Question

Most important requirement for evolution

Answer 1

the most important requirement for evolution is genatic variation

Answer 2

The most important Requirements for evolution are genetic variation and natural selection.  Genetic variation gives the organism to sustain several alterations in its gene. These variations often end up unlocking some special properties and mutations which help the species endure harsh climatic conditions and thus evolve.  Natural selection is yet another way though not as much as the evolution depends on variations in the genetics of the species.