A study of 1,003,805 trees across 1,568 locations in Africa, Amazonia, and Southeast Asia reveals that a small number of common tree species account for a large proportion of the trees in these tropical forests. The research estimates that 2.2%, 2.2%, and 2.3% of species in these regions make up 50% of the trees, with a total of 1,053 species accounting for half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differences in biogeographic, climatic, and anthropogenic histories, the study finds consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. The study also highlights that focusing on the most common species can provide insights into the ecology and dynamics of tropical forests, as these species constitute the majority of the trees. The research underscores the importance of understanding the biology of these common species to better model the response of tropical forests to environmental change. The study also identifies a manageable list of species that are likely to be hyperdominant, which could facilitate targeted research on their ecology. The findings suggest that tropical forests, despite their diversity, can be understood through the lens of a relatively small number of common species. The study also highlights the need for further research on the taxonomy and ecology of these species to improve our understanding of tropical forest dynamics.A study of 1,003,805 trees across 1,568 locations in Africa, Amazonia, and Southeast Asia reveals that a small number of common tree species account for a large proportion of the trees in these tropical forests. The research estimates that 2.2%, 2.2%, and 2.3% of species in these regions make up 50% of the trees, with a total of 1,053 species accounting for half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differences in biogeographic, climatic, and anthropogenic histories, the study finds consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. The study also highlights that focusing on the most common species can provide insights into the ecology and dynamics of tropical forests, as these species constitute the majority of the trees. The research underscores the importance of understanding the biology of these common species to better model the response of tropical forests to environmental change. The study also identifies a manageable list of species that are likely to be hyperdominant, which could facilitate targeted research on their ecology. The findings suggest that tropical forests, despite their diversity, can be understood through the lens of a relatively small number of common species. The study also highlights the need for further research on the taxonomy and ecology of these species to improve our understanding of tropical forest dynamics.