Ancient teeth reveal mammalian responses to Climate Change in Southeast Asia over the last 150,000 years
Archaeologists working deep within Coc Muoi cave during a Vietnamese-French collaborative field campaign. The illuminated excavation area yielded fossil teeth of Pleistocene mammals, later analyzed for their chemical signatures to reconstruct ancient diets and environments.
© Truong Huu Nghia, Anthropological and Palaeoenvironmental Department of Vietnam's Institute of Archaeology
To the point
- Isotopic Analysis: A new study shows that ancient mammals' dietary flexibility influenced their survival during climate changes over the past 150,000 years in Southeast Asia.
- Research Findings: The study analyzed 141 fossil teeth and found that animals with varied diets survived better, while specialists with narrow diets went extinct. Generalist species like sambar deer and wild boar showed wide isotopic ranges, indicating adaptability, while specialists like orangutans and tapirs had narrower profiles linked to specific habitats.
- Conservation Implications: The study emphasizes the importance of conserving ecological conditions, not just species, to ensure their survival amid ongoing deforestation in Southeast Asia. Insights from past species responses to environmental pressures can help predict modern species' resilience and inform future conservation efforts.
A new study led by the Max Planck Institute of Geoanthropology uncovers how flexibility made the difference between survival and extinction. By analyzing fossil teeth from Vietnam and Laos, an international team reconstructed the diets and habitats of extinct, extirpated, and still-living species. The results show that animals with varied diets and habitats were more likely to endure, while narrow specialists largely disappeared.
The team examined 141 fossil teeth dating from 150,000 to 13,000 years ago and combined them with existing records. Using stable isotope analysis of carbon, oxygen, nitrogen, and zinc, they examined dietary responses to environmental shifts. "By analyzing chemical traces in tooth enamel, we can piece together ancient diets and environments in remarkable detail," says lead author Nicolas Bourgon. "Comparing species across time shows why some survived while others vanished."
Generalists survived environmental shifts
Examples of fossil teeth analyzed in this study, including specimens of 1) a macaque, 2) an extinct giant tapir, 3) a wild boar, 4) a wild large-sized bovid, 5) a tiger, 6) a porcupine, 7) a Sumatran rhinoceros, 8) a dhole, 9) an orangutan and 10) a giant panda.
© Nicolas Bourgon
Animals like sambar deer, macaques, and wild boar proved adaptable, as reflected in wide isotopic ranges. In contrast, specialists such as orangutans, tapirs, and rhinoceroses showed narrower profiles tied to particular habitats. As environments shifted, generalists endured while specialists were left vulnerable. Orangutans, now limited to Borneo and Sumatra, once ranged widely across Southeast Asia. Isotope results suggest they consistently relied on fruit from closed-canopy forests, even during environmental change.
"Even though modern orangutans can turn to alternative foods during hard times, their survival still depends on intact forests," says Nguyen Thi Mai Huong, co-author from the Anthropological and Palaeoenvironmental Department of Vietnam's Institute of Archaeology. "It looks like this has been true for tens of thousands of years."
With Southeast Asia facing the fastest tropical deforestation worldwide, the lessons from the past are urgent. "Understanding how species coped with ancient pressures helps predict their resilience today," said senior author Patrick Roberts of the Max Planck Institute. The study highlights the need to conserve not just species, but the ecological conditions that sustain them. "This is about more than just ancient animals," Bourgon adds. "It's about learning from the past to protect the future."
