To converge or not to converge in environmental space: testing for similar environments between analogous succulent plants of North America and Africa

Despite the widely accepted notion of convergent evolution between North American cacti and African succulent plants, this study reveals significant environmental differences that challenge this assumption. Analyzing five hotspots—two in Mexico and three in South Africa—the research employed niche modeling tools, randomization tests, and multivariate analyses to compare climatic conditions. Results showed more climate differences than similarities, with notable variations in rainfall and temperature regimes, suggesting that edaphic factors may also play a role. While some pairwise comparisons (e.g., Cuatrociénegas-Richtersveld) exhibited environmental similarity, the broader analysis indicated that these sites, though drylands with moderate drought and mild temperatures, are not as environmentally convergent as previously thought. This study underscores the importance of rigorous environmental assessments in studies of convergence.

Alvarado-Cárdenas, L. O., Martínez-Meyer, E., Feria, T. P., Eguiarte, L. E., Hernández, H. M., Midgley, G., & Olson, M. E. (2013). To converge or not to converge in environmental space: testing for similar environments between analogous succulent plants of North America and Africa. Annals of Botany, 111(6), 1125–1138. https://doi.org/10.1093/aob/mct078