We don't want to turn this into a debate between the creationists and the evolutionists but more and more scientific evidences have been emerging stating that humans are not entirely different from animals. We don't know where the great Descartes is right now but his "I Think Therefore I Am" philosophy is currently being bombarded.

Many people believe that many of our more gentle emotions and moral reasoning are part of the human soul that was created by one almighty being. However, evolutionary biologists and cognitive neuroscientists are beginning to find out that these are actually connected genes, brain structures, and other physical correlates.

Quite interestingly, the above-mentioned physical manifestations were also found on animals. This, if taken to be true, will prove that humans' high level of thinking and moral judgment is still part of the evolution process. University of California San Diego brain scientist V. S. Ramachandran put it,

There may be soul in the sense of "the universal spirit of the cosmos" but the soul as it is usually spoken of, "an immaterial spirit that occupies individual brains and that only evolved in humans" - all that is complete nonsense. Belief in that kind of soul is basically superstition.

Instead of eliminating the notion of a human soul in order to make us humans fit seamlessly into the rest of nature, it's wiser to recognize that there is something analogous to soul in all living beings. I think all of our hominid ancestors were ensouled in some way, but that does not rule out the possibility that as evolution continues, the shape of the soul can vary just as it does from individual to individual.