Housing and Development Newsletter Still, radiocarbon dating cost the team more than $100 per specimen. Given the cost and facilities this requires, it’s a significant issue in terms of scientific and cultural equity for researchers and communities in regions with fewer resources invested in the paleosciences, the authors said. These two studies alone have increased the number of reliably dated traces of past human activity from the island by more than 75%. “So this is a massive contribution and increase in just building up the chronology for human arrival and activity in Madagascar,” Douglass said. Diets and Interactions The team also analyzed ratios between two stable isotopes of both carbon and nitrogen to investigate the ecology of ancient animals. Ratios of carbon isotopes are sensitive to the type of photosynthesis different plants employ. Woody plants, like trees and shrubs, tend to use C3 photosynthesis.