Phylogenomics of the Hyalella amphipod species-flock of the Andean Altiplano

Francesco Zapelloni,Damià Jaume,Joan Pons,Carlos Juan,José A Jurado-Rivera

doi:10.1038/s41598-020-79620-4

Francesco Zapelloni, Damià Jaume + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-79620-4

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Abstract

Species diversification in ancient lakes has enabled essential insights into evolutionary theory as they embody an evolutionary microcosm compared to continental terrestrial habitats. We have studied the high-altitude amphipods of the Andes Altiplano using mitogenomic, nuclear ribosomal and single-copy nuclear gene sequences obtained from 36 Hyalella genomic libraries, focusing on species of the Lake Titicaca and other water bodies of the Altiplano northern plateau. Results show that early Miocene South American lineages have recently (late Pliocene or early Pleistocene) diversified in the Andes with a striking morphological convergence among lineages. This pattern is consistent with the ecological opportunities (access to unoccupied resources, initial relaxed selection on ecologically-significant traits and low competition) offered by the lacustrine habitats established after the Andean uplift.

Highlights

Species diversification in ancient lakes has enabled essential insights into evolutionary theory as they embody an evolutionary microcosm compared to continental terrestrial habitats
The Maximum Likelihood (ML) phylogenetic tree robustly supports Hyalella as a monophyletic clade divided into two major lineages: one comprising H. franciscae, and all the representatives of clade C, which consists of one not yet formally described species of the Titicaca with smooth body integument—H. “krolli”—that is sister to the heavily armoured Titicacan H. armata, and another sister lineage sampled at the western border of the Altiplano (Laguna Súchez-Huaytire) represented by a species with smooth body integument
The second highly supported major lineage encompasses the North American species H. azteca, and all the remaining South American species (Titicaca + Altiplano clades A, B, D and E plus the taxa from Ecuador clade from the southern Ecuador highlands (clade F)), with all subclades supported with maximum bootstrap values except the node relating clades A and B

Summary

Introduction

Species diversification in ancient lakes has enabled essential insights into evolutionary theory as they embody an evolutionary microcosm compared to continental terrestrial habitats. Like many other ancient lakes such as the East African ones, the Altiplano lakes have experienced a complex palaeo-environmental history as the water level was subjected to at least three significant expansions from the Early to Middle Pleistocene. These shifts resulted in the joining of the different lake basins of the Altiplano into a single hydrological u nit[8,9,10]. These disagreements were proposed to derive by rapid morphological and ecological differentiation coupled with phenotypic c onvergence[21,22,23]

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