Dualists, as animals evolve higher thought processes, at what point do you believe they inherit a non-corporeal "self" or soul?

Cartesian Dualism is the belief that human awareness of being aware is above the physical plane of mater-energy-space-time, that there is a non-physical or spiritual thing in us that is the “me” or “I”. Dualism was advanced by early thinkers such as Zarathustra, Plato and Aristotle but perhaps best captured by René Descartes in 1641 in his aphorism, Cogito ergo sum or “I think, therefore I am.” or more fully, “I am thinking, therefore I exist.” or “I am thinking, on the account of being.”

So, if self awareness can’t possibly be understood as a brain activity, but requires having a non-corporeal soul, at what point of increasing self awareness does an animal such as a chimp or bonobo or killer whale get supplied with a soul? Do all animals from the simplest single-celled organism up have souls? If so, how come they can’t think as humans do?