The way species are spread across the planet is not by chance; it is influenced by various evolutionary processes and both historical and present environmental factors. Since the mid-19th century, researchers have identified several primary areas known as biogeographic realms, which showcase these extensive collections of species worldwide. These realms offer a crucial framework for understanding biodiversity on Earth and are widely utilized in different biology disciplines.
The way species are spread across the planet is not by chance; it is influenced by various evolutionary processes and both historical and present environmental factors. Since the mid-19th century, researchers have identified several primary areas known as biogeographic realms, which showcase these extensive collections of species worldwide. These realms offer a crucial framework for understanding biodiversity on Earth and are widely utilized in different biology disciplines.
For almost 150 years, however, the classification of these biogeographic areas has been primarily based on the study of vertebrates (like birds and mammals) and certain plant groups. Yet, these groups account for only a small fraction of the total species on Earth. On the other hand, highly diverse groups such as insects have largely been overlooked in these efforts, making it difficult to use this knowledge for conservation planning and comprehending biodiversity distribution.
Recently, ecologists from The University of Hong Kong (HKU) and their collaborators from Japan have created a global biogeographic map for ants, a significant insect group. This project marks the first attempt to take these creatures into account, as detailed in a publication in Nature Communications. This research provides a valuable perspective for understanding how insects are distributed and holds importance for global conservation efforts.
Insects, often referred to as ‘the little things that run the world’, account for more than 55% of all classified species. However, the lack of distribution data about these creatures hampers scientists’ ability to chart their biogeographic regions. ‘A crucial first step in protecting species and biodiversity is knowing where they are found,’ states Professor Benoit GUÉNARD, the senior author of the study and head of the Insect Biodiversity and Biogeography Laboratory at HKU School of Biological Sciences (SBS).
To address this issue, Professor Guénard has been leading an international team dedicated to compiling distribution data on approximately 16,000 ant species for over ten years. Ants are some of the most widespread and ecologically significant insects, representing a biomass that can be up to double that of wild birds and mammals, according to previous studies led by Professor Guénard. For insects, ants are relatively well-studied. The diligent effort of Professor Guénard’s team, which has involved over 300 years of ant research, enabled them to utilize advanced methods such as bioinformatics and machine learning to predict and analyze the distribution of ants. Ultimately, they created the first biogeographic map of ants.
This map categorizes the global presence of ants into nine significant biogeographic realms. ‘Interestingly, when I compared this map to those of vertebrates and plants, I found many resemblances,’ remarks Mr. Runxi WANG, a PhD candidate in the School of Biological Sciences, ‘notably with ants and plants sharing several areas that do not appear in vertebrate maps.’
Further analysis reinforces the authors’ findings — biogeographic regions are strikingly similar across different groups, with plants showing more resemblance to ants than to any vertebrate groups. ‘This isn’t particularly surprising, as we understand that ants and plants have a closely knit ecological and evolutionary relationship. For example, ants assist countless plants in spreading their seeds and provide protection from herbivores. They have evolved together for millions of years,’ explains Professor Guénard, ‘and this is among the first pieces of evidence demonstrating such significant biogeographic implications.’
This outcome suggests that numerous similarities between animal and plant distributions may not be reflected in vertebrate species. ‘While ants alone cannot represent the immense diversity of all insects, their relationship with plants might not be unique,’ notes Mr. Wang, ‘and we definitely need to make greater efforts to include more insect groups in the future to create a complete picture of global biodiversity.’
