STARKVILLE, Miss.—Mississippi State University biologist Matthew W. Brown is part of an international research team whose latest findings, published this spring in the Proceedings of the National Academy of Sciences , are reshaping scientific understanding of how parasitic organisms evolve and ultimately spread disease.
Focusing on the protistan parasite Leishmania, a genus of trypanosomatids that is globally spread through insect bites, the study provides critical insight for developing more effective interventions and treatments of parasitical infections.
Brown, the Donald L. Hall Professor of Biology in MSU’s Department of Biological Sciences, contributed to the study’s genetic analyses and interpretation of evolutionary patterns.
“Understanding how these parasites exchange genetic material fundamentally changes how we think about their evolution and adaptability,” Brown said. “This work shows these parasitic organisms readily exchange genetic material—it’s actually a dominant force shaping these organisms, with real implications for disease dynamics and control strategies worldwide.”
The study, “Extensive heterozygosity and genetic exchange among natural populations of Leishmania species,” challenges longstanding assumptions that Leishmania populations reproduce primarily through clonal, or asexual, expansion. Instead, researchers found more than 70% of sampled parasite isolates showed evidence of genetic mixing, indicating sexual reproduction and hybridization play a major role in their evolution.
This latest publication builds on Brown’s broader body of work exploring how complex organisms evolved from microbial ancestors.
Last fall, Brown was part of a different international team whose groundbreaking discovery was published in Nature , identifying a new organism, Solarion arienae, and establishing a new phylum and previously unrecognized eukaryotic supergroup. That work provided new insight into the earliest stages of complex life on Earth .
In recognition of his research contributions, Brown was named the 2025 recipient of MSU’s Ralph E. Powe Research Excellence Award, the university’s highest honor for research achievement.
A leading figure in evolutionary biology, Brown has authored more than 70 peer-reviewed publications with nearly 10,000 citations and has secured about $4 million in research funding. He also recently received an $870,000 collaborative grant from the Gordon and Betty Moore Foundation to expand a widely used software suite for building large-scale evolutionary datasets.
Since joining MSU in 2013, Brown has earned numerous accolades, including the College of Arts and Sciences Dean’s Eminent Scholar Award and election as a fellow of the Institute for Genomics, Biocomputing and Biotechnology.
The study published in the Proceedings of the National Academy of Sciences is available online at www.pnas.org/doi/10.1073/pnas.2537999123 . For more details about Brown’s research, visit www.amoeba.msstate.edu .
Visit www.cas.msstate.edu and www.biology.msstate.edu for more information about MSU’s College of Arts and Sciences and Department of Biological Sciences.
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Proceedings of the National Academy of Sciences
Data/statistical analysis
Cells
Extensive heterozygosity and genetic exchange among natural populations of Leishmania species
17-Apr-2026
The authors declare no competing interests.