Darwin explained that evolution occurred by a mechanism called natural selection. the environment determines the fitness of an organism which depends on adaptations that the organism survive and reproduce.

The main role of dna in the  cell is the long-term storage of information. it is often compared to a blueprint, since it contains the instructions to construct other components of the  cell, such as  proteins  and rna molecules.the main function of rna is to carry information of amino acid sequence from the genes to where  proteins  are assembled on  ribosomes  in the  cytoplasm. mark brainliest, my work is good.

Google - what is the first three eras within the phanerozoic eon