  We propose an alternative scenario for the dark matter generation from an
evolving cosmological constant which interacts with the dominant background in
certain intermediate phase of the universe, and relaxes to the observed small
value at present. In this way, it is shown that the interaction of the
cosmological constant with the radiation or matter might generate the dark
matter densities with a varied mass spectrum in the universe with their
characteristic arc-like frozen signatures on the Cosmic Microwave Background
Radiation (CMBR). This approach also suggests a possible solution to the long
standing cosmological constant problem.
