Original title: Comparative phylogenetic analyses of limestone and non-limestone Begonias in Peninsular Malaysia
Ruth Kiew, Fathmath Shaman Fareed, Lian Chee Foong, Sheh May Tam · September 2026
Limestone rocks called karsts host unique plant life, but scientists want to understand how these plants evolved. Begonias are flowering plants that grow on many surfaces, like limestone, granite, and forest soil. Many live in only one spot. To trace their history, researchers analyzed DNA from chloroplasts and cell nuclei across 30 Begonia species in Peninsular Malaysia. By building an evolutionary family tree and calculating when species split, they tracked how Begonias spread over time. They found that Begonias arrived from continental Asia around 10.65 mya during the mid-late Miocene period. The plants split into two main branches through at least two separate arrivals. Then, they moved into limestone habitats three separate times. Interestingly, climate shaped their diversity more than the rock types they grew on. Today, quarrying, mining, and human encroachment threaten these plants and their karsts, which mostly lack legal protection.
Imagine you are a gardener trying to grow the same flower in different parts of your yard. Some spots have clay soil, some have sandy soil, and some are rocky. You expect the soil type to decide which flowers thrive. But you notice that flowers in sunny, dry spots do well regardless of soil, while flowers in shady, wet spots struggle even in good soil. Here, the researchers studied Begonia plants on limestone and non-limestone soils. They found that the climate—like sun and rain in the garden—was more important than the soil type in determining where new species evolved.
Limestone karsts in Southeast Asia are biodiversity hotspots, but many lack legal protection. This study shows that climate, not just the rock type, drove the evolution of Begonias—a mega-genus with many endemic species. Conservation strategies must account for climate history to protect these unique plants.
The study is limited to 30 Begonia species from Peninsular Malaysia, so broader geographic and taxonomic sampling is needed. The role of genome size variation and physiological inertia in species cohesion remains speculative. Conservation recommendations are not detailed, and the legal protection status of many karsts is still lacking.
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Comparative phylogenetic analyses of limestone and non-limestone Begonias in Peninsular Malaysia — Ruth Kiew, Fathmath Shaman Fareed, Lian Chee Foong et al. — bioRxiv — doi:10.64898/2026.09.10.750513
Abstract licence: CC BY
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.