Darwin’s Carnivorous Plant Prediction Confirmed
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Doug Soltis and colleagues confirmed Darwin’s prediction that saxifrages are carnivorous by demonstrating insect digestion and nutrient absorption in Saxifraga candelabrum, ending a long-standing botanical debate.
- Saxifraga candelabrum traps small insects like gnats with sticky glandular hairs while allowing larger pollinators to escape, suggesting an evolved mechanism for selective prey capture.
- Hang Sun and team detected digestive enzymes in the plant’s secretions and used nitrogen isotopes to trace nutrients from digested prey into the plant’s tissues, fulfilling key criteria for carnivory.
- Genetic analysis revealed that Saxifraga shares molecular pathways with known carnivorous plants such as sundew and flycatcher bush, providing independent genomic evidence of its carnivorous status.
- Charles Darwin first proposed saxifrages might be carnivorous in 1875 after observing insect-trapping behavior, but lacked the tools to prove digestion or nutrient uptake at the time.
Why it matters: This confirmation reshapes the scientific understanding of plant carnivory, showing it evolved across broader lineages than previously thought. For botanists and evolutionary biologists, it means re-evaluating hundreds of saxifrage species — many with similar glandular hairs — for potential carnivorous traits, expanding the scope of ongoing research in plant adaptation.
