Every year, the third Saturday in February is World Pangolin Day. Pangolins are the only mammals covered in scales and among the most trafficked wild animals in the world. Over the past 20 years, more than 900,000 pangolins have been illegally hunted due to traditional medicine and food transactions, putting them in serious danger of extinction. In particular, the Malayan pangolin and the Chinese pangolin (also known as the Manis pentadactyla) have been designated as 'critically endangered' on the International Union for Conservation of Nature (IUCN) Red List since 2014.
Recently, a research team including the Chinese Pangolin Conservation Research Center and Northeast Forestry University analyzed high-resolution genomic data of Malayan and Chinese pangolins to protect the species and assessed their risk of extinction. The research results were published in the open-access scientific journal GigaScience.
Genomics is essential for understanding how healthy a population is. By examining how high the genetic diversity is, it is possible to predict the likelihood of the population being maintained healthily. The higher the genetic diversity, the greater the possibility that the next generation will be maintained healthily. However, if genetic diversity is low, increased inbreeding can lead to a decrease in the survival rate of the population.
Utilizing advanced deoxyribonucleic acid (DNA) analysis technology, researchers obtained genetic information from 109 pangolins, including 37 Chinese pangolins and 72 Malayan pangolins. By using the latest genomic techniques to accurately read and assemble long DNA fragments, they secured genomic data with much higher resolution than before.
Based on the genomic data, the conservation status of five pangolin populations was reassessed, revealing that overall genetic diversity was higher than expected. However, one Malayan pangolin group and a Chinese pangolin found in Taiwan exhibited low genetic diversity and high inbreeding rates, indicating a significant risk of extinction. The Malayan pangolin population has experienced the fastest decline in numbers over the past 10,000 years. The Chinese pangolins discovered in Taiwan showed particularly high occurrences of identical sequences in their genes, suggesting they have been genetically isolated due to continuous inbreeding.
Based on this, the research team noted that one reason pangolins struggle to survive is the weak 'genetic purification effect.' Genetic purification is the process by which harmful mutations naturally disappear. However, in pangolin populations, this process does not occur effectively due to inbreeding, leading to a higher likelihood of harmful genes remaining.
Currently, the Chinese government has been cracking down on illegal poaching and transactions to protect pangolins, establishing breeding centers for the conservation of both Chinese and Malayan pangolins and developing artificial breeding and restoration programs. The researchers emphasized that "customized conservation strategies are needed based on the genetic characteristics of each population," adding, "It is essential not only to prevent illegal poaching but also to stop breeding between close relatives and appropriately mix pangolins from different regions to enhance genetic diversity."
Professor Tianming Ran, who led the research, said, "Thanks to this genomic analysis, we were able to more precisely understand the genetic structure and health status of wild pangolin populations" and added that, "We could improve the 're-wilding strategy' for returning captive pangolins to nature."
References
GigaScience (2025), DOI: https://doi.org/10.1093/gigascience/giaf003