ORIGINAL ARTICLE
doi:10.1111/evo.13657
How mountains shape biodiversity: The role of the Andes in biogeography, diversification, and reproductive biology in South America’s most species-rich lizard radiation (Squamata: Liolaemidae)
Damien Esquerre,´ 1,2 Ian G. Brennan,1 Renee A. Catullo,1,3 Fernando Torres-Perez,´ 4 and J. Scott Keogh1 1Division of Ecology and Evolution, Research School of Biology, The Australian National University, 0200 Canberra, Australian Capital Territory, Australia 2E-mail: [email protected] 3School of Science & Health and Hawkesbury Institute for the Environment, Western Sydney University, 2751 Perth, New South Wales, Australia 4Instituto de Biologıa,´ Pontificia Universidad Catolica´ de Valparaıso,´ 2950 Valparaıso,´ Chile
Received June 13, 2018 Accepted November 19, 2018
Testing hypotheses on drivers of clade evolution and trait diversification provides insight into many aspects of evolutionary biology. Often, studies investigate only intrinsic biological properties of organisms as the causes of diversity, however, extrinsic properties of a clade’s environment, particularly geological history, may also offer compelling explanations. The Andes are a young mountain chain known to have shaped many aspects of climate and diversity of South America. The Liolaemidae are a radiation of South American reptiles with over 300 species found across most biomes and with similar numbers of egg-laying and live- bearing species. Using the most complete dated phylogeny of the family, we tested the role of Andean uplift in biogeography, diversification patterns, and parity mode of the Liolaemidae. We find that the Andes promoted lineage diversification and acted as a species pump into surrounding biomes. We also find strong support for the role of Andean uplift in boosting the species diversity of these lizards via allopatric fragmentation. Finally, we find repeated shifts in parity mode associated with changing thermal niches, with live-bearing favored in cold climates and egg-laying favored in warm climates. Importantly, we find evidence for possible reversals to oviparity, an evolutionary transition believed to be extremely rare.
KEY WORDS: Adaptive radiation, diversification, Liolaemus, Phymaturus, viviparity.
One of the enduring questions in evolutionary biology is why successful diversification across biomes, including adaptive some lineages diversify explosively, producing many species and radiations (Schluter 2000; Losos 2010; Magnuson-Ford and phenotypes in comparatively short periods of time (Losos 2010). Otto 2012). Rapidly appearing, heterogeneous, and fragmented Explanations typically involve the specifics of a clade’s biology, geological systems such as oceanic islands, lakes, and mountains the environments in which they live, and interactions between the provide ample opportunity for some groups to explosively radiate two (Barnosky 2010). The ability of particular lineages to rapidly (Baldwin and Sanderson 1998; Losos 2009; Drummond et al. evolve biological traits (e.g., diet, reproduction, or behavior) 2012). When initially formed, these systems provide novel habi- in response to changing environments is thought to underlie tats free of competitors, which provides time and space to adapt.