Over the last 15 years, the field of landscape genetics has experienced a rapid increase in the number of analytical tools for linking landscape and genetic data. Most of these developments have focused on evaluating landscape effects on genetic connectivity, for example in the form of “Isolation-by-Resistance or “Isolation-by-Barrier”. However, the quality of the matrix is only one landscape attribute that can influence neutral genetic variation, and genetic exchange is only one mechanism behind landscape-genetic relationships. There is a general lack of considering alternative, more complex environmental influences on genetic variation. Indeed, the lack of more holistic predictions, testable hypotheses and underlying theory in landscape genetics has recently caused several authors to criticize the field and to question its distinction and purpose relative to older scientific disciplines. Here, I attempt to derive testable predictions of landscape-genetic relationships in wildlife that go beyond the typical “Isolation-by-…” framework. For this, I review several general principles and findings from population and behavioral ecology, ask how they are affected by landscape complexity in space and time, and how these effects translate into genetic patterns.
Results/Conclusions
I use a graphical approach to show relationships i) between landscape complexity, population dynamics and individual behavior, and ii) between these ecological mechanisms and population genetics, thus providing indirect links between landscape complexity and genetics (i.e., landscape-genetic relationships). I use various examples from terrestrial wildlife species to illustrate how such indirect links can help to derive expectations of landscape-genetic relationships and how testing these expectations can increase the ecological meaningfulness of landscape genetic studies. Based on this work, I conclude that landscape resistance is only one of many landscape-genetic relationships, and that landscape dynamics (i.e., changes of landscape patterns across time) will often have greater effects on genetic variation and underlying ecological processes than static landscape structure. I suggest several future research needs to broaden the ecological basis of landscape genetics, including comparative and experimental studies, as well as temporal monitoring. While my examples focus on neutral landscape genetics, I highlight that the general approach can also be used to derive testable expectations in adaptive landscape genetics.