Are plants the naural inhabitants of the earth and animals aliens?

Question

Is it possible that all heterotrophs including animals and humans once invaded or reached earth by chance to sustain here feeding on plants and on one another? Is it not strange not to find a single animal develop autotrophic or photosynthetic ability since millions of years evolution? Even todays' symbiots and little predators do mimic charecteristics of the prey enabling them to ctch their prey easily. So may it be possible if early predators aquired cellulr features similar to plants enabling them to live together?

Answer 1

no, there are several genes that are shared between plants and animals, which conclude that they both share a common ancestor.