Why it is in the news
A study in Science Advances (vol. 12, article eaeg3488), reported by The Hindu on 12 October 2026 as published on 3 September 2026, shows that sex-reversed male agile frogs (Rana dalmatina) in Hungary, genetically female (XX) but physically normal, fertile males, make up about 20% of adult males in wild populations yet sire only about 4% of egg clutches. The lead author is Veronika Bókony of the HUN-REN Centre for Agricultural Research. Their offspring were more likely to undergo sex reversal themselves (61% against 17% for offspring of ordinary males) and carried higher ranavirus loads after a simulated heatwave; population models project that heat-driven sex reversal could drive some small populations extinct within 60–70 years.
The exam angle
Issue: Climate warming can threaten biodiversity through demographic mechanisms such as sex-ratio distortion, which standard habitat-loss assessments do not capture.