Yes it has, it's one of the core things you adjust in most real applications. It's a trade-off between exploration and exploitation. If you speciate then you h

Yes it has, it's one of the core things you adjust in most real applications. It's a trade-off between exploration and exploitation. If you speciate then you have little sub-populations exploiting the local maxima, so they might do better. However, now you're not searching such a wide area so you're more likely to spend your time struggling to the top of the molehill that's next to the mountain. In nature this also happens. Not having crossovers between ludicrously different things is generally a good idea because the landscape is full of tiny maxima. If you change a load of base pairs in your DNA you're less likely to be able to do things like form cells or process glucose than you are to add some awesome new power (unless we're in comic books). One of the major differences for nature is that it can run all this jazz in parallel. If there are resources, it can happily have 10 trillion bacteria rather than 5 without any cost. When we're simulating, every fitness measurement on a piss-poor crossover is a waste that we should have spent on a more likely solution. It all depends on the fitness landscape, but both approaches can be better on different real world problems.