I think we are in an interesting in human devopment. We have widespread knowledge through the Internet. We have a strong lessing of power in fundamentalist religions. And we have a strong advance of science and technology.
I think "Intelligent Design" will be a better model to understand the future of humanity rather than evolution. (At least I hope.) Evolution has gotten us here, but we are changing faster than evolution works. We will start modifying our genetics - get rid of genetic diseases and gradually accept enchancements. We will become more cybornetic as we accept nanomachines and cell phones integrated into our bodies. We will change our base biological behavior. Why use evolution's solution when we can decide for ourselves what we should feel. Maybe lower our aggression? Maybe increase our desires?
Now I see this happening over hundreds of years. I can also see many ways this could all fail and we enter another dark age. However, I have a lot of optimism that we can keep advancing.
For me, polyamory is part of this change. One step on the path.