HYDERABAD: A recent study by researchers at the CSIR–Centre for Cellular and Molecular Biology (CCMB) has uncovered how species evolved and disappeared across South Asia and the wider Asian region. The study, led by Dr Jahnavi Joshi’s lab, was published in Ecology Letters and represents the first large-scale evolutionary analysis of its kind for Asia.
Dr Joshi explained, “Our team analysed 33 well-studied groups of animals and plants using mathematical models to trace patterns of speciation (the formation of new species) and extinction across the region. Each group includes closely related endemic species that share a common ancestor. Over millions of years, their descendants dispersed across landscapes and diversified into the many species we see today.”
What makes this discovery particularly striking is the ecological stability observed in the region, despite its turbulent geo-climatic history.
Pragyadeep Roy, the study’s first author, noted, “Peninsular India was once part of the Gondwanaland supercontinent along with present-day Africa and Australia. It drifted away roughly 100 million years ago and collided with Asia, eventually giving rise to the Himalayas. Despite these massive geological changes, the region’s biodiversity has remained relatively stable, highlighting the resilience of its forest habitats.”
However, about half of the groups studied exhibited fluctuating rates of speciation and extinction over time.
“The Earth’s climate has changed significantly over millions of years, and our analyses suggest that global temperatures strongly influence how new species emerge in many groups,” the researchers stated.
“We found that several groups experienced abrupt shifts in speciation between 11 and 3 million years ago—a period marked by intense aridification and seasonal monsoon patterns in peninsular India. This era saw a dramatic expansion of grasslands and a retreat of evergreen forests to isolated refuges like the Western Ghats and Eastern Ghats mountaintops.