Twenty-Year Progress in Landscape Genetics of Tetrapods.

Landscape genetics, an interdisciplinary field integrating population genetics, landscape ecology, and spatial analytical techniques, has progressed significantly over two decades, yet systematic reviews of its application to tetrapods remain limited. Here, we review 385 studies published between 2003 and 2025, covering 434 species across eight geographic regions, to assess taxonomic and geographic bias, common research questions, analytical approaches, and key environmental drivers of genetic variation. Our results show that Anura and Passeriformes are the most frequently studied groups, while threatened species were particularly poorly represented. North America dominates geographically, followed by Europe, while Asia, South America, Africa, and Oceania remain poorly sampled. Most studies investigate genetic connectivity and population structure, frequently employing Mantel tests, AMOVA, and STRUCTURE, although recent work increasingly applies SNP-based genomic tools to detect both neutral and adaptive variation. Habitat permeability, topography, and artificial landscapes consistently influence genetic variation. These findings emphasize the need for expanded research across diverse tetrapod taxa and ecosystems, with particular attention to threatened species and populations, better integration of genomic and ecological data, and stronger connections to conservation planning to preserve genetic connectivity and diversity in rapidly changing landscapes.