The British geneticist and evolutionary biologist J B S Haldane observed that the Dasavataras (ten principal avatars of Lord Vishnu) provide a true sequential depiction of the great unfolding of evolution. The avatars of Vishnu show an uncanny similarity to the biological theory of evolution of life on earth.[not in citation given] Avatars Explanation Evolution Matsya. First avatar is a fish, one which is creature living in water. If we compare it with biological evolution on different Geological Time Scale first developed life was also in the form of fish which originated duringCambrian period. Kurma Second avatar was in the form of Tortoise (reptiles). In geology also first reptiles comes as second important evolution which originated in Mississippian period just after Amphibians. Varaha Third avatar was in the form of Boar. Evolution of the amphibian to the land animal. Narasimha The Man-Lion (Nara= man, simha=lion) was the fourth avatar. But in geology no such evidences are mentioned. It may have been related with Ape Man The term may sometimes refer to extinct early human ancestors. Vamana Fifth Avatar is the dwarf man. It may be related with the first man originated during Pliocene. It may be related with Neanderthals. Neanderthals were generally only 12 to 14 cm (4½–5½ in) shorter than modern humans, contrary to a common view of them as "very short" or "just over 5 feet". Parashurama, The man with an axe was the sixth avatar. It has the similarities with the first modern man originated during Quaternary period or the man of Iron Age.
Lord Rama, Lord Krishna and Lord Buddha were the seventh, eighth and ninth other avatars of Lord Vishnu. It indicates the physical and mental changes and evolution in the man from its time of appearance.
For me this is a perfect example of projecting a modern view onto ancient thought. I don't find the argument they represent the process of evolution convincing.