Premise: Plants, particularly those with limited distribution ranges and small population sizes, are expected to be severely impacted by changing climatic conditions. Sesamum species are ideal for Species Distribution Modeling (SDM) in the context of climate change due to their narrow distribution ranges, agricultural and economic significance, sensitivity and adaptability to environmental conditions, wide geographic range, and potential to inform policy and adaptation strategies Methods: We used Maximum Entropy (MaxEnt) Model to quantify global ecological niche breadth of species in the genus Sesamum and to assess how bioclimatic and soil heterogeneity indices impact the future (to the year 2080) suitable distribution ranges of the genus Sesamum. We also quantified which environmental variables contribute most to driving the patterns and suitable geographical ranges for Sesamum. Results: Maxent models accurately predicted suitable habitats for Sesamum species. Precipitation patterns, especially seasonal extremes, were key determinants of species distribution. Temperature also influenced habitat suitability, with specific requirements varying among species. These findings highlight the complex interplay between climate and edaphic factors in shaping species distributions. Species with broader niches have larger geographic ranges. However, future climate change is predicted to reduce niche breadths for most species (74%), with some facing substantial range contractions. In contrast, a few species (11%) are projected to expand their ranges, while other species (15%) will experience negligible impacts. Phylogenetic analysis did not reveal significant patterns in extinction risk and niche breadth evolution. Conclusion: This study highlights the vulnerability of Sesamum species to climate change, with projected reductions in range sizes necessitating urgent conservation efforts. Prioritizing species such as S. forbesii and S. sesamoides, alongside targeted actions such as habitat restoration and long-term monitoring, is crucial to prevent population decline and potential extinction.

Retracing pathways of historical species introductions is fundamental to understanding the factors involved in the successful colonization and spread, centuries after a species’ establishment in an introduced range. Numerous plants are thought to have been introduced to regions outside their native ranges by European voyagers and early colonists making transoceanic journeys; however, records are scare to document this. We use genotyping-by-sequencing and genotype-likelihood methods on the selfing, global weed, Plantago major, collected from 50 populations worldwide to test hypotheses that the plant was brought to new regions during colonial times. We further investigate how patterns in genomic diversity facilitate the success of this global weed. Although genomic differentiation among populations is found to be low, we identify six unique ecotypes showing very little sign of admixture. Three of the most prevalent of these ecotypes present in the native range gave rise to introduced populations in the Americas, Africa, Australia and New Zealand, indicating that more than one successful ecotype colonized and spread. The distribution of ecotypes is found to have links to colonial history, and ecotypes are further found to be restricted by latitude. Dispersal of multiple successful ecotypes and prior adaptation in the native range to latitudinally dependent environmental factors (such as climate) are likely reasons for the success of this prolific, global weed. Genomic signatures can provide new perspectives on the drivers behind the historic introductions and the successful colonization of introduced species in an era of global change.