# Pleistocene Climate Oscillations and Geographic Barriers Shaped the Phylogeographic Structure of Anaplecta omei (Blattodea, Blattoidea, Anaplectidae) in Southern China: Evidence From Mitochondrial Genomes

## TL;DR

This study shows how climate changes and geography shaped the genetic structure of Anaplecta omei in southern China.

## Contribution

The study reveals that Pleistocene climate and geographic barriers, not adaptation, caused genetic differentiation in A. omei.

## Key findings

- A. omei shows high haplotype diversity but low nucleotide diversity and a clear phylogeographic structure.
- Major intraspecific divergences in A. omei occurred during the Pleistocene, followed by population expansions in refugia.
- Tectonic uplift and complex topography, along with climate oscillations, shaped the species' genetic structure.

## Abstract

Anaplecta omei is the only species of Anaplecta widely distributed in southern China yet the processes shaping its genetic structure and range remain unclear. We used 97 complete mitochondrial genomes from 24 distinct geographic populations to characterize the genetic diversity, population structure, and evolutionary history of A. omei. Phylogenetic reconstruction, genetic diversity assessment, and population structure analysis revealed high haplotype diversity but low nucleotide diversity and a clear phylogeographic structure comprising four well‐differentiated groups. Selection tests indicated no group‐specific shifts in selective pressure, suggesting that physical barriers rather than adaptive divergence underlie this structure. Divergence‐time estimates showed that interspecific splits among Anaplecta date to the Miocene, whereas major intraspecific divergences within A. omei occurred during the Pleistocene, and demographic analyses (neutrality tests, mismatch distributions, and Bayesian skyline plots) indicated that the divergence within A. omei was followed by late‐Pleistocene population expansions in regional refugia. Together, these results indicate that tectonic uplift, Pleistocene climate oscillations, and complex topography have jointly shaped the phylogeographic diversification and distribution of A. omei, shedding light on diversification processes in Blattodea inhabiting montane landscapes.

We used 97 complete mitochondrial genomes from 24 distinct geographic populations to characterize the genetic diversity, population structure, and evolutionary history of Anaplecta omei. Our results indicate that tectonic uplift, Pleistocene climate oscillations, and complex topography have jointly shaped the phylogeographic diversification and distribution of A. omei, shedding light on diversification processes in Blattodea inhabiting montane landscapes.