FOREWORD: I apologize for any huge gaps in logic here. I've never put my thoughts on this topic down on "paper" before, so it's at best iffy, at worst terminally flawed. Either way, nice to be able to collect my thoughts. Just a warning from a guy without any background in philosophy that the philosophy up ahead may well be rubbish.

Perhaps more to the point: Can there be an afterlife without a soul? No. Since an afterlife implies some sort of continued consciousness, it cannot be had without a means of immaterial containment and transfer of said consciousness, which would otherwise pass with the body. Reincarnation does not fit the bill for an afterlife, as the consciousness is not persistent, and is therefore instead just the continuation of an initial animating force.

Now then, assuming there is a God, and assuming that said God has created mankind in order to see which of these is faithful unto It, then I think an afterlife is possible (but not necessarily implied). This iteration of God has a desire (if not a need) for affection or validation, which It has attempted to fill by the creation of creatures (humans) capable of loving/needing, but which are also capable of self-direction. The God has placed these creatures in an environment which can potentially distract them from Its intended purpose for them, a purpose which, if achieved, gratifies the God. This is where it splits: humans can either function as pets or companions. As pets, our company is enjoyed until we pass away, at which time we cease to have any sort of connection. Since it does not take a soul to be self-directed, an afterlife would not exist in this scenario. However, as companions, life becomes a proving ground for establishing the sort of company which would be pleasing to the God to have on a continued basis. In this way It achieves diverse, yet agreeable, companions, and an afterlife becomes a possibility.

But if one believes in Darwinian evolution, then the God/human model loses a lot of weight, even if God is only viewed as a First Mover. Why would all these millions of years of soulless life exist leading up to the advent of the soul-bearing human if the goal is an afterlife populated by humans? In the context of time being something more than a man-made interpretation of change to explain decay, I'd say that actually rules out an afterlife by way of nixing likelihood of the human soul.

I guess the ultimate point is that an afterlife implies soul, soul implies purpose, and purpose implies a sentient God.