Plant Thermogenesis: Did Heat Evolve Before Colour in Pollination?

The proposition that heat acts as a distinct biological signal forms the core of new research into plant thermogenesis. While colour and scent are established vectors for attraction, this study argues that thermal infrared radiation functions as a primary lure for specific beetle species, potentially rewriting the timeline of pollination evolution. The findings rest on a dual-mechanism observation: heat production in plants and infrared detection in insects.

The researchers focused on the physiological mechanics on both sides of the interaction. In the plants, mitochondrial adaptations were observed to generate heat in a circadian rhythm. Conversely, the beetles' antennae were found to possess neurons activated by infrared light, housing ion channels apparently tuned to the specific frequency of the plant's thermal output. This lock-and-key mechanism is the study's strongest evidence. It moves beyond mere correlation to demonstrate a functional biological interface.

Evolutionary Implications of Plant Thermogenesis

Comparative analysis within the paper suggests a chronological hierarchy. The authors posit that infrared signalling is an ancient modality, likely existing before the visual dominance of flowers. If accurate, this implies a shift from invisible thermal cues to the vibrant visual displays we recognise today. However, we must remain cautious. Inferring behaviour in deep time based on modern physiological traits requires significant extrapolation.

While the mechanism exists now, the exact prevalence of this trait in the fossil record remains a matter of inference rather than direct observation. This research highlights a hidden layer of ecological interaction. It does not negate the role of scent or colour but adds a thermodynamic dimension to our understanding of plant-insect co-evolution. Future replication across a wider range of plant species is necessary to determine if this is a niche adaptation or a fundamental, widespread precursor to modern pollination strategies.