Daubian Santos is a postdoc at the Universidade Federal do ABC, Brazil. He is a evolutionary biologist with special focus on biogeography of craneflies. Here, Daubian presents SAMBA, a method for revealing shared patterns of biotic distribution.
Dr. Daubian Santos, postdoc at Universidade Federal do ABC, Brazil
Institute. Universidade Federal do ABC, Brazil, Institute of Systematics and Evolution of Animals
Academic life stage. Postdoc
Major research themes. Biogeography and Palaeontology
Current study system. I study craneflies. Craneflies are mosquitoes with long legs that may reach impressive sizes. This infraorder is ancient, highly endemic, and widely distributed throughout the world. They inhabit a range of environments, from glaciers to deserts, from urban areas to the canopy of tropical forests. Interestingly, the number of species within this group exceeds the combined number of mammals and birds. Despite the large number of known species, there are still many yet to be discovered, including some of the larger size ones. Therefore, studying craneflies presents an excellent opportunity to explore biodiversity.
Recent JBI paper. Santos, D., Sampronha, S., Hammoud, M., Gois, J. P., & Santos, C. M. D. (2023). SAMBA: Super area‐cladogram after resolving multiple biogeographical ambiguities. Journal of Biogeography, 50(4), 816–825. https://doi.org/10.1111/jbi.14569
A piece of Baltic amber containing a specimen of Eloeophila eocenica, the newest described species
Motivation behind this paper. Historical biogeography has been a relevant field for a considerable period, providing insights into species evolution and dispersal over time. However, with the discovery of more complex species distributions, more efficient methods are required to tackle these challenges. Unfortunately, there are not many new and effective methods available, and most of them do not have online software, which makes it difficult for researchers to access them. In response, we became very motivated to develop a new methodology based on simple theoretical principles, providing reliable results to overcome the lack of consensus in area cladograms. Improving methods in historical biogeography will provide a better understanding of life’s evolution and distribution on Earth.
Key methodologies. The main key methodology of SAMBA is to avoid using assumptions. By avoiding the use of assumptions, SAMBA aims to reduce the amount of noise in the analysis, resulting in more accurate and reliable findings. It is crucial in the field of historical biogeography to see the individual complexity of the distributions and identify the recurrent pattern accurately. As a novel approach, we adapted the method of super-trees that allows an efficient summarization of information from area cladograms. The innovative approach of SAMBA, and its online implementation, is a new way to analyse the data and may provide new insights into the distribution of life on Earth. More and more studies with new methods may bring a lot of new information.
Fossil of the family Limoniidae from the Brazilian Cretaceous period
Unexpected challenges. Proposing and developing something new is never an easy task. After establishing the theoretical framework of the methodology, the further step was to test it. However, since the computational implementation was developed later, we had to conduct many (and many) tests before arriving at the final SAMBA protocol. This testing period provided us valuable time to rethink certain aspects of the methodology. The adaptation of the super-tree concept came later, but it was essential in refining the SAMBA method. The implementation of the super-tree concept allowed us to summarise information from area cladograms and achieve a more consensus-based approach. Although the development process was challenging, the final product is a robust and reliable methodology. The thinking-and-rethinking process is necessary to make any method useful.
Major results. My work formalized the new method of historical biogeography called SAMBA. This methodology avoids using assumptions and aims to summarise information with minimal noise. In addition to the methodology, we tried to provide a computational implementation to increase the method’s applicability and efficiency. This method was tested under real examples and theoretical models and compared with other previous methodologies. This new method is efficient to summarise the area cladogram information. We believe that the SAMBA methodology and its computational implementation can provide a valuable tool for researchers in the field of historical biogeography with a simplified theoretical basis.
Described paratypes of Aphrophila edwardsi
Next steps for this research. I will start a post-doctoral research project focusing on mosquitoes preserved in Baltic amber. This project is particularly interesting because it will provide insights into the composition of Eocene ecosystems, in which craneflies played an essential role. During this period, Europe was characterized by subtropical forests, and the insect fauna that followed was more similar to the modern pattern. However, the shift of biotas during this time is not yet fully understood. Craneflies are the most commonly found Diptera in the paleontological record, and studying these species is crucial to unravelling this fascinating period of evolution.
If you could study any organism on Earth, what would it be? I would like to study the first winged insect. The evolution of wings is still one the greatest mysteries in Entomology.
Anything else to add? When I started college, I had a strong desire to study any animal, except mosquitoes. However, it was precisely them that I ended up studying! I was both surprised and fascinated by its enormous diversity. It is incredible how much we can learn from these small, but enchanting beings.
Difference of size of two Brazilian craneflies