IsoTroph · Advanced techniques in isotopic biogeochemistry for the estimation of fossil mammal trophic position
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2022-09-01 → 2024-08-31
- EU contribution
- €174,806
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Advanced techniques in isotopic biogeochemistry for the estimation of fossil mammal trophic position
A deep understanding of present and past food web dynamics is crucial for comprehension of the evolution of ecosystems and sustainable management of natural and anthropogenic environments. In this field, isotope paleoecology holds a vast potential for investigating organism-environment interactions in a diachronic view. Following the fundamental principle that every organism reflects the stable isotope composition of its diet, the isotope analysis equalized the possibilities to study the ecology of contemporary and fossil animals. One of the most common uses of stable isotopes in paleoecology is estimating an animal's trophic position (TP). TP estimation is possible due to the metabolic fractionation of isotopes, followed by the progressive predominance of heavier isotopes over light ones through the trophic chain. For bone collagen, the nitrogen isotopic composition in collagen is widely used as a proxy of TP due to distinct fractionation of 15N and 14N isotopes along the trophic chain, resulting in higher 15N concentrations in consumers in relation to their food. The 15N to 14N ratio is denoted as δ15N, i.e., in relation to an internationally defined standard, atmospheric nitrogen. Higher δ15N values can be interpreted as a higher trophic position of the specimen. This heavy isotope enrichment between a consumer and its diet can be quantified as a trophic discrimination factor (TDF). This parameter is used in numerical modeling to track detailed trophic relationships of individuals and between taxa. More detailed TP estimations are possible when individual TDFs of particular amino acids of collagen are compared. The IsoTroph project aimed at bringing methodological improvements to the single amino acid isotopic analysis of terrestrial mammals' bone collagen. In particular, the scientific objective of the project was focused on the δ15N glutamate-phenylalanine (Glx-Phe) trophic discrimination factor (TDFGlx-Phe) in bone collagen of terrestrial carnivorans. This quantitative parameter is crucial in reconstructions of TP, but its numerical value has never been directly measured in mammal collagen. The specific research questions to investigate in the project were: 1. Is the 7.6‰ value, usually adopted in paleoecological studies, an exact approximation of the collagen-to-collagen TDFGlx-Phe in mammals? 2. Is the collagen-to-collagen TDFGlx-Phe constant between different mammal consumers? The conclusions are that the TDFGlx-Phe=7.6‰ is not valid for mammalian bone collagen, but the actual value is around the range of 4.5-5.5‰ and seems constant among terrestrial carnivorans.
Data: CORDIS, © European Union
Project objective
The principal objective of the IsoTroph project is to improve the geochemical method used in paleontology of terrestrial mammals, through the application of stable isotopes of single amino acids in paleoecology. In particular, the project focuses on a single amino acid (glutamate and phenylalanine) δ15N trophic discrimination factor (TDF). It is a quantitative parameter used in reconstructions of past animal or human trophic positions (a primary consumer – a herbivore; a secondary consumer – a carnivore feeding on herbivores; etc.), crucial for understanding the evolution of environments. The TDF has never been established before for terrestrial mammals, although it is a key parameter in modelling the past ecology.The main research method of IsoTroph is the analysis of δ15N in bone collagen of a population of a predator and that of its prey, and then calculating the TDF between these populations. To achieve this, the project will involve a study of modern populations (collections of recent bones of wolf, lynx, red fox, and their prey, from Białowieża Forest and fox den), as well as a collection of fossils from a Pleistocene carnivore den (cave hyena and its prey). These collections will provide insight into four species of mammalian carnivores, representing variable ecology (both hypercarnivores and omnivores), and different chronology (recent and Pleistocene).The project offers a great chance for professional training in a new method with a vast potential to be used in paleoecology – the stable isotope composition of single amino acids. This training is to be performed through research, which will bring the high quality results of the greatest interest for a wide audience of scientists currently involved in paleoecological studies of animals and humans. The project will deliver answers on the direct collagen-to-collagen TDF, which was never determined before, and which will be broadly applied in future isotopic studies in ecology and paleoecology.
Original text from CORDIS.
Participants
- EBERHARD KARLS UNIVERSITAET TUEBINGEN · TuebingenCoordinatorGermany
Links
Data: CORDIS, © European Union