Thanks for pointing this out. I had a look at http://www.evolvingai.org/files/1504.04909v1.pdf. It's an interesting read, although I'm not sold on the value of feature space exploration. I think it muddies the waters around the problem of balancing optimization with diversity, by lumping decisions and constraints together. What's to stop it from over-sampling regions of the decision space that have a steep gradient in the other features?

What's to stop the discovered solutions from being similar? Nothing but the dimensions of interest. If the best solutions with respect to features a, b, and (a&b) are all the same, then it does not seek different solutions.

This may indicate you chose reduntant features though.

Here's an interesting application that provides some motivation. https://arxiv.org/abs/1407.3501

Regarding the similarity of solutions:

If, in a particular region, your model outputs are particularly sensitive to the inputs, that region can be overrepresented in a feature map. What I mean by this is that we cannot effectively choose between the solutions in this region -- the region is small compared to our ability to control inputs. Overrepresenting such a region in a population-based search starves the rest of the problem space of the algorithm's attention.

Thanks for the link, by the way -- this is a particularly interesting application.