April 25, 2024

How Prehistoric Humans Adapted to Intense Climate Change – Revealed by Marine Mollusk Shells

Cantabrian coast (N Iberian Peninsula). Credit: Asier García Escárzaga
Present international environment warming is having, and will continue to have, widespread repercussions for human history, in the same method that ecological variations had substantial effects for human populations in the past. The sweeping impacts of the 8.2 ka (kilo year, or thousand years ago) occasion on human societies and various environments are frequently assumed rather than shown.
The journal Scientific Reports has actually released a paper led by Asier García Escárzaga, existing scientist from the Institute of Environmental Science and Technology (ICTA-UAB) and the Department of Prehistory of the Universitat Autònoma de Barcelona, together with Igor Gutiérrez Zugasti, from the Universidad de Cantabria (UC). The study was coordinated from the Universidad de La Rioja (UR) and the Max Planck Institute (Germany) alongside members of other academic centers (Max Planck Institute, University of Burgos, Universidad Complutense de Madrid and University of Faro)..
The study uses a multidisciplinary toolkit of archaeomalacological research studies and steady oxygen isotope analyses to shell stays recovered from the shell midden website of the El Mazo cavern (Asturias, N Spain). With a long stratigraphic sequence of 1,500 years, El Mazo is a distinct context along the European Atlantic coast, with particularly high chronological resolution of each archaeological layer.

Current international environment warming is having, and will continue to have, prevalent effects for human history, in the same way that environmental variations had significant consequences for human populations in the past. One of the most commonly consumed species, the warm-adapted species P. lineatus, reduced throughout the 8.2 ka occasion, while populations of cold-adapted P. vulgata, another typically made use of species, increased. The authors argued that this happened since of human market growth in these Atlantic seaside settings which acted as refugia during this cold event, encouraging populations to move there from more inland.

The outcomes obtained by these scientists allowed them to figure out that cooler seawater temperatures, deduced from steady oxygen isotope values measured on marine shells, resulted in changes in the availability of various shellfish types. For instance, among the most commonly taken in species, the warm-adapted species P. lineatus, reduced throughout the 8.2 ka event, while populations of cold-adapted P. vulgata, another commonly exploited types, increased. Intriguingly, the warm-adapted limpet P. depressa also increased during this cool duration, owing to a greater resistance to cold temperature levels than other warm-water types.
Their results likewise exposed a boost in the increase of mollusk exploitation by people, as shown by a reduction in typical mollusk size and evidence for increased harvesting in more dangerous coastal areas. The authors argued that this took place since of human group development in these Atlantic seaside settings which functioned as refugia throughout this cold event, motivating populations to move there from further inland. Populations around El Mazo managed to prevent over exploiting their seaside resources, as typical mollusk size very seldom decreased below 20mm, the minimum size specified by modern-day guidelines to guarantee long-lasting types survival.
” Our results recommend a continuous application of regional marine eco-friendly knowledge by some of the last foragers in western Europe, despite significant changes to environment and demography,” says Asier García-Escárzaga lead author of the existing research study.
The resolution offered by the mix of taxonomic, geochemical, and chronological analysis of mollusks from historical sites has significant implications for other studies seeking to identify the significance of climate modification on marine environments, and can provide in-depth clues to the magnitude and nature of future climate changes and their effects on human societies.
Reference: “Human forager reaction to abrupt environment change at 8.2 ka on the Atlantic coast of Europe” by Asier García-Escárzaga, Igor Gutiérrez-Zugasti, Ana B. Marín-Arroyo, Ricardo Fernandes, Sara Núñez de la Fuente, David Cuenca-Solana, Eneko Iriarte, Carlos Simões, Javier Martín-Chivelet, Manuel R. González-Morales and Patrick Roberts, 20 April 2022, Scientific Reports.DOI: 10.1038/ s41598-022-10135-w.