Landscape Genetics of Mammals in American Ecosystems

Abstract

Since the term was coined in 2003, landscape genetics (LG) is a field that integrates population genetics, landscape ecology, and spatial analytical techniques to quantify the effects of landscape on microevolutionary processes. Despite the growing interest in LG, there is little knowledge about the trends in LG research for America in general and regarding mammals in particular, as well as about which ecosystems are being most studied. Deserts represent nearly one-third of the Earth’s surface and are characterized by high heterogeneity and species richness. However, they are underrepresented in the LG literature. Hence, we performed a thorough review of published scientific articles addressing LG of mammals in America, with emphasis on deserts. The objectives were to 1) determine the mammal groups that have been most studied; 2) establish the representation of desert ecosystems; 3) describe the research questions and analytical methods most frequently used; and 4) summarize the key landscape factors and environmental variables associated with genetic diversity and structure patterns of mammals in America. We conducted a comprehensive literature search of published articles between 2003 and 2019 in the Web of Science (http://apps.webofknowledge.com) based on search words specific to the revision subject. We verified and screened the articles recovered, and gathered basic information (species, authors, publication year), together with the research questions addressed and the genetic and statistical methods used. We recovered 36 publications on LG involving mammals in America; of these, only eight were conducted on desert ecosystems (Table 1). Rodentia was the most represented order in all American ecosystems (n = 20), while Artiodactyla (n = 4) was specifically represented in deserts. Of all studies, the most common research questions focused on estimating ‘connectivity’ (n = 14) and ‘genetic structure’ (n = 12), and the most frequent analytical methods were Mantel and partial Mantel tests. Dispersal capabilities and vegetation cover were the most important variables regarding the genetic structure of desert populations. Most studies evaluated connectivity with simple and partial Mantel tests, but the use of novel methodologies (i. e., genomics) was also identified. Ecological traits of species, particularly for rodents, and vegetation cover were the main factors related to genetic patterns in deserts. Notably, we identified that North America is the most studied region, while LG studies with mammals are scarce in Mexico and South America (one study encompassed North and Central America), as well as in desert ecosystems, hence the urgency to conduct studies in those regions and in deserts.