Seventy-nine percent of endemia species show declins, stressing how fragile the island’s biodiversity is in the face of changes in ecosystem.
Insects play an essential role in ecosystems, from pollinal plants to the decomposition of driving and to maintain nutritious cycles. Their diversity and abundance are crucial for ecological stability, but recent evidence of generalized declines have raised serious concerns about how insects adapt to modern environmental pressures. Determine whether these reductions reflect long -term trends are essential for global conservation strategies and to discover the causes of what has been called “the apocalypse of insects”.
In a study published in ScienceScientists from the Okinawa Institute of Sciences and Technology (OIST) applied a community genomic approach to study the populations of Fiji ants as a broader insect biodiversity model. By sequencing the genomes of the museum specimens, they have rebuilt the evolutionary history of ants, traced when the species colonized the islands and examined the dynamics of the long -term population.
Conservation monitoring often emphasizes large charismatic animals and ecosystems that are easier to study, such as temperate regions. However, many insects have steep drops, and island ecosystems – rich in unique cash – are particularly vulnerable. Dr. Evan Economo, professor at the OIST and at the University of Maryland and the main author of the study, explained: “It can be difficult to estimate the historical changes of insect populations, because with a few exceptions, we have not directly followed the populations over time. We adopt a new approach to this problem by analyzing the genomes of many species in parallel from specimens which recently allow. community level changes. »»
The team’s conclusions were striking: 79% of endemic antics species of Fiji – those that have not found themselves anywhere – do not decline signs of decline, with the moment of these reductions aligning on human arrival on the islands. On the other hand, the species of non -native ants introduced by people develop quickly. A large part of the decline seems to have intensified in the last hundreds of years, coinciding with European contacts, colonization, world trade and the spread of modern agriculture.
A community level approach
By focusing on the Fijien archipelago, a region of long -term interest in researchers, they were able to obtain a wide complete overview of population changes and the history of colonization of almost all different anti -ants in the region. “The closed, isolated ecosystems, the islands should feel the effects of the human impact faster, so they are a kind of canary in the coal mine,” notes Dr. Cong Liu, the first author of this document.
However, studying the populations of the tropical islands is not without challenges. Often, work in the field can be extremely difficult and it is not easy to do continuous surveys. Consequently, instead of relying on the surveillance of the field in real time, here the team has used collections of museums built through decades of work in the field, including the previous collection efforts of the team and those of other entomologists.
Musumomics: reconstructing the colonization of ants
A challenge to use museum collections is that DNA deteriorates over time. Consequently, the researchers had to use special sequencing methods (Museumomics) to compare small DNA fragments. In this study, they sequenced samples of genomes of thousands of ants of more than a hundred species of different confirmed ants.
Using this data, they identified 65 distinct instances (colonization events) where new species of ants came to the island. These went from natural colonization (that is to say the arrival of ants without human involvement) millions of years ago to the recent human introduction after the Fiji was one of the world’s commercial networks.
Based on this story, the researchers have been able to use their population genetics models to identify the rise or decline of the population of different ants groups throughout the Fijian archipelago, noting the decline of endemic species, as well as spectacular increases in the population of non -indigenous species in recent years.
Insular endemic species have often changed features that make them sensitive to environmental changes, including the arrival of new harmful species. “Most of the recorded extinctions have historically come from island systems,” adds Dr. Liu.
Go beyond the archipelago
The team hopes that this work will be able to act as an inspiration for future work to continue to build a scientific understanding of the populations of insects and to shed light on conservation efforts. “This study also highlights the importance of biodiversity and museum collections,” said Professor Alexander Mikheyev of the Australian National UniversityA main author of this study. “As our scientific toolbox develops, there is more and more information that we are able to capture from biodiversity collections, it is therefore essential that we continue to invest and maintain these vital resources.”
The team also examines this locally, to measure the biodiversity of Okinawa insect populations in real time thanks to acoustic monitoring and trapping as part of the Okinawa environmental observation network (Okeon).
“Insects are essential to the environment,” said Professor Economic. “As scientists, we must play our role in their protection and provide and analyze the relevant data to ensure long -term integrity of our ecosystems.”
Reference: “The genomic signals have indicated a loss of biodiversity in an endemic islands fauna” by Cong Liu, Eli Sarnat, Jo Ann Tan, Julia Janicki, John Deyrup, Masako Ogasawara, Miquel L. Grau, Lijun Qiu, Francisco Hita Garcia, Georg Fischer, Akanisi Caginnitoba, Narla, Clive T. Darwell, Yasuhiro Kubota, Naomi E. Pierce, Alexander S. Mikheyev and Evan P. Economo, September 11, 2025, Science.
Doi: 10.1126 / Science.ADS3004
Funding: Okinawa Institute of Science and Technology Graduate University, Japan Society for the Promotion of Science, Japan Society for the Promotion of Science, Japan Society for the Promotion of Science, Museum of Comparative Zoology, Harvard University
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