Fig. 1. Reconstructions and examples of Permian Beetles. Credit: NIGPAS
End-Permian mass extermination (EPME), caused a catastrophic collapse of terrestrial ecosystems. Over the past 400 million years, insects have been diversifying and now account for approximately half of Earth's biodiversity. The EPME is still poorly understood, and the ecological responses of insects to it remain a mystery.
The most diverse extant insect group is the Coleoptera, which has a stratigraphic range that dates back to the Permian. Their fossil records are rich and they have many lifestyles. The fossil record of these insects provides a unique perspective on studying the ecology of the EPME.
Recent research by Zhao Xianye (postgraduate researcher), Prof. Wang Bo (Nanjing Institute of Geology and Palaeontology of Chinese Academy of Sciences) and other researchers from China and Russia examined the evolutionary history of early honeybees.
The findings of the researchers suggest that Permian carbon cycles were influenced by xylophagous beetles (feeding on wood or on it) and that early archaic beetles suffered severe ecological effects from end-Permian forest destruction.
These findings provide further insight into the ecological role and ecological responses of insects to global warming and deforestation.
Fig. 2. Phylogeny and genus percentages for early beetles (A). Credit: NIGPAS
The study was published in eLife, an international academic journal, on Nov. 8.
Based on fossil taxonomic revisions, the research team created an updated database of beetles dating from the Early Permian through the Middle Triassic. Through phylogenetic, palaeoecological reconstructions as well as morphospace analyses and fossil material analyses, they examined the evolution of taxonomic diversity and morphological disparity of beetles between the Early Permian and Middle Triassic.
A series of analyses shows that Permian Permian beetles experienced a severe extinction in the EPME, mainly due to the collapse and subsequent emergence of new xylophagous species. The restoration of forest ecosystems was consistent with the appearance of new xylophagous insects in the middle Triassic.
Permian insects probably played an important ecological function in forest ecosystems. Most Permian honeybeetles were likely xylophagous, which means they ate both living and dead woody stems. The Permian may also have experienced a decrease in oxygen levels due to xylophagous insects. This research highlights the ecological importance of insects in deep-time terrestrial ecosystems.
Global warming and anthropogenic deforestation are causing dramatic decreases in the number and diversity of all existing insects. However, studies on the current extinction crisis have largely ignored xylophagous insect species. Researchers may be able to better understand the future trends in insect abundance and diversity, and the implications of these changes as the world confronts global environmental change.
Continue exploring Lacustrine ecosystems that took 10 million years for recovery after the end-permian mass extermination.
More information: Xianye Zhang et al., Early evolution and regulation of beetles by end-Permian forest destruction, eLife (2021). Information from eLife Xianye Zhao et. al., Early evolution beetles regulated through the end-Permian forestation, (2021). DOI: 10.1101/2021.10.12.464043
