Scientists at the National University of Singapore (NUS) have identified a crucial DNA “switch” that enables tropical butterflies to modify their wing patterns according to seasonal temperature changes. This significant finding, published in the journal Nature Ecology & Evolution on October 24, 2025, could enhance understanding of how species adapt to environmental shifts, particularly in the context of climate change.
The study, led by Professor Antónia Monteiro, focuses on the Bicyclus anynana, a butterfly species known for its striking seasonal variations. During the wet season, these butterflies develop larger eyespots on their wings, while in the dry season, these spots shrink. This seasonal plasticity plays a vital role in their survival, yet its genetic basis has remained largely elusive until now.
Research indicates that temperature influences the size of these eyespots during the caterpillar stage. The satyrid butterfly group, which includes the Bicyclus anynana, exhibits a pronounced response to temperature changes. The NUS team pinpointed a key gene, Antennapedia (Antp), responsible for regulating eyespot development. The gene’s activity fluctuates with the temperature at which the butterflies are reared, confirming its essential role in seasonal adaptation.
In their investigation, the researchers discovered a unique DNA promoter—essentially a switch—that specifically activates the Antp gene in the central cells of the eyespots. Disabling this switch significantly hampered the butterflies’ ability to adjust eyespot size based on temperature, underscoring its importance in the evolution of their environmental adaptability.
Dr. Tian Shen, the primary author of the paper and a former graduate student and postdoctoral fellow at NUS, remarked on the implications of their findings. He stated, “It is striking that a simple genetic switch can underlie complex environmental sensitivity across a broad group of insects.” This breakthrough opens avenues for further research into how similar genetic elements contribute to adaptation, which is increasingly vital as species face the realities of a changing climate.
The ability of insects to adapt to their environments through such genetic mechanisms provides insight into evolutionary processes and highlights the importance of conservation efforts aimed at protecting these species as their habitats continue to evolve due to climate change. Understanding the genetic foundations of such adaptations could help inform strategies for preserving biodiversity in a rapidly changing world.
