How close to a relative should one settle? David Aguirre et al have shown that relatedness has an effect on colonization and settlement in some species, at least.
Here’s David’s summary of the paper that is now on Early View in Oikos:
“In organisms with sessile adults (e.g. many plants and marine invertebrates) variation in the density of colonisers is known to have a profound influence on the structure of populations and communities. Recent studies also indicate that the relatedness among interacting adults can be an important driver of differences in ecological performance among populations. Thus, it is surprising that few studies have examined the effects of relatedness on the non-adult life-history stages, and thereby the effects of relatedness on colonisation processes. In our study we bridged the gap between these two lines of ecological enquiry, and found that the effects of relatedness on colonisation differed in direction and magnitude in four sessile marine invertebrates.”