An old sample tells a good story: the evolutionary history of mammals from the diagonal of open vegetation of South America told by biological collections

Abstract

The loss of animal diversity due to anthropogenic impacts is one of the main threats to the planet. This panorama is even more critical in little-known but diverse regions of the globe, such as the diagonal open formations in South America. This region includes the Caatinga, Cerrado, and Chaco biomes. In common, they all have vegetations adapted to seasonal rains and severe droughts, unique biotas with complex distributions, and have received less research attention than tropical forests. Understanding how the abiotic characteristics acted in the formation of the biodiversity of small mammals is the focus of this proposal. Mammals of the orders Rodentia, Didelphimorphia, and Chiroptera represent the greatest diversity of mammals in the Caatinga and Cerrado. Their diversity patterns reflect intrinsic characteristics of the biomes but also current and historical connections with their neighboring biomes. However, tracing direct causal links between abiotic factors and the structuring of taxa diversity is a challenge due to the complicated geological and climatic dynamics of the Neotropical region. Integrating data types, as well as the methodological advances brought by genomics, can help trace these links. For this purpose, these biomes will be sampled through field expeditions and visits to scientific collections, and from then on, two paths will be used. The first will focus on comparative phylogeography accessing (i) the genetic variation and (ii) the demographic history of taxa, testing (iii) demographic synchronicity between communities, and (iv) alternative landscape evolution scenarios for the ecosystems, in addition to making (v) predictions of future demographic trends of taxa. The second path aims to contribute to the (vi) delimitation and description of species in an integrative approach, in addition to (vii) establishing phylogenetic hypotheses for the groups of interest. Other expected results include the expansion of the MZUSP collection, the updating of the list of species in the region, the production of a barcode library, subsidies for the formation of public conservation policies, scientific publications, the training of new mammalogists, and educational actions at MZUSP. (AU)