Does Buddhism account for the origin of life or of existence in general?
Unlike many religions, Buddhism does not have a strong cosmological component. That isnt to say that there is no such thing as Buddhist cosmology, but on the whole Buddhism simply accomodates the cosmology of the current culture as long as it doesnt stand in direct contradiction to the Dharma. Buddhism does not accept doctrines of a personal creator or First Cause and in fact considers such notions to be incoherent. Questions about the origin of life arent really germane to Buddhist practicethat is, theres no objection to asking or contemplating such questions, but they have nothing to do with Buddhist practice per se and, if they develop into objects of intellectual and/or emotional attachment, can become active hindrances to the practice.