Evolution and diversification of the Southern Chilean genus Ceroglossus (Coleoptera, Carabidae) during the Pleistocene glaciations

Abstract

The Quaternary glaciations affected the evolution and current distribution of taxa in southern Chile, including the emblematic and endemic genus Ceroglossus Solier. This genus of ground beetles has fascinated a great number of entomologists due to their conspicuous colour patterns, but despite this attention their taxonomy has remained controversial, with a large amount of taxa described based on unclear or variable morphological characters. In this work, we carry out a phylogenetic analysis of the 10 described species of Ceroglossus, based on mitochondrial and nuclear markers, and perform a species delimitation analysis using different algorithms, to clarify the backbone of their evolutionary tree and to lay the basis for a comprehensive and integrative taxonomic revision of this genus. Our results show that Ceroglossus is divided in five main lineages, composed of 13 putative phylogenetic species. The five lineages diverged before the Quaternary, while the divergence of the species within each lineage occurred during the glaciations and followed a parallel pattern among the different lineages. Additionally, we carry out an evolutionary interpretation of the revised available chromosomal data to shed light on the mechanisms that promoted their diversification.

Chromosomal Radiation: A model to explain karyotypic diversity in cryptic species

“… White et al (1967 ) published the idea of a mechanism of chromosomal change acting on the emergence of species which was followed by many biologists. Over the years, besides the criticism, several authors claim that a range of organisms presenting different “chromosomal races” could evolve by the process proposed by White ( 1968 ), the Stasipatric Speciation ( Shaw and Wilkinson, 1980 ; Watanabe and Kawanishi, 1983 ; Michailova, 1992 ; Frisman et al, 2009 ; Ruiz-García et al, 2011 ; López-López et al, 2021 ; Zamudio et al, 2023 ; among others). Stasipatric speciation is a model of non-allopatric speciation in which a chromosome rearrangement that reduces fitness when heterozygous is taken to be the post-mating isolating mechanism that confers species status on a population.…”

Breaking the Law: Is It Correct to Use the Converse Bergmann Rule in Ceroglossus chilensis? An Overview Using Geometric Morphometrics

“…The genus Ceroglossus (Coleoptera: Carabidae) encompasses a group of colorful ground beetles endemic to temperate forests of southern South America [25,26]. The genus comprises eight described species: C. chilensis (Eschscholtz), C. darwini (Hope), C. speciosus Gerstaecker, C. magellanicus Géhin, C. buqueti (Laporte), C. suturalis (Fabricius), C. ochsenii (Germain) and C. guerini (Germain), although it may harbor higher taxonomic diversity [27]. Most of the species exhibit a striking pattern of sympatric color convergence hypothesized as a product of Müllerian mimicry [28].…”