The effect of unsampled sites on Mantel <i>r</i> statistics testing isolation by distance.

<p>Each iteration represents the addition of one site to the network, such that sites are the least connected (panels a and b) or the most connected (panels c and d), for both the marten (<i>Martes americana</i>) and fisher (<i>M. pennanti</i>) datasets. The dashed line is the Mantel <i>r</i> (95% CI) statistic for the full dataset. Isolation by distance is the relationship between <i>cGD</i> and log Euclidean distance.