Isotopic analyses of collagen, the main protein preserved in subfossil bone and tooth, has long provided a powerful tool for the reconstruction of ancient diets and environments. Although isotopic studies of contemporary ecosystems have typically focused on more accessible tissues (e.g. muscle, hair), there is growing interest in the potential for analyses of collagen because it is often available in hard tissue archives (e.g. scales, skin, bone, tooth), allowing for enhanced long-term retrospective studies. The quality of measurements of the stable carbon and nitrogen isotopic compositions of ancient samples is subject to robust and well-established criteria for detection of contaminants and diagenesis. Among these quality control (QC) criteria, the most widely utilized is the atomic C:N ratio (C:N-Atomic), which for ancient samples has an acceptable range between 2.9 and 3.6. While this QC criterion was developed for ancient materials, it has increasingly being applied to collagen from modern tissues. Here, we use a large survey of published collagen amino acid compositions (n = 436) from 193 vertebrate species as well as recent experimental isotopic evidence from 413 modern collagen extracts to demonstrate that the C:N(Atomic)range used for ancient samples is not suitable for assessing collagen quality of modern and archived historical samples. For modern tissues, collagen C:N(Atomic)falling outside 3.00-3.30 for fish and 3.00-3.28 for mammals and birds can produce systematically skewed isotopic compositions and may lead to significant interpretative errors. These findings are followed by a review of protocols for improving C:N(Atomic)criteria for modern collagen extracts. Given the tremendous conservation and environmental policy-informing potential that retrospective isotopic analyses of collagen from contemporary and archived vertebrate tissues have for addressing pressing questions about long-term environmental conditions and species behaviours, it is critical that QC criteria tailored to modern tissues are established.
Quality control for modern bone collagen stable carbon and nitrogen isotope measurements
Review badges
Web of Science (Free Access)
Abstract
- Contribute
- pre-publication peer review (FINAL ROUND)
Decision Letter
2020/05/2828-May-2020
MEE-20-03-231.R1 Quality Control for Modern Bone Collagen Stable Carbon and Nitrogen Isotope Measurements
Dear Dr Eric Guiry,
It is a pleasure to accept your manuscript entitled "Quality Control for Modern Bone Collagen Stable Carbon and Nitrogen Isotope Measurements" in its current form for publication in Methods in Ecology and Evolution. Final instructions for your manuscript, and some promotion options, can be found at the end of this email.
Thank you for your fine contribution. On behalf of all Editors of Methods in Ecology and Evolution, I look forward to your continued contributions to the Journal.
Sincerely,
Dr Aaron Ellison
Senior Editor, Methods in Ecology and EvolutionReply to:
Ms India Stephenson
Methods in Ecology and Evolution Editorial Office
coordinator@methodsinecologyandevolution.orgWhy not become a member of the British Ecological Society? https://www.britishecologicalsociety.org/jointhebes
Decision letter by
Cite this decision letter
- pre-publication peer review (ROUND 1)
Decision Letter
2020/05/2626-May-2020
MEE-20-03-231 Quality Control for Stable Carbon and Nitrogen Isotope Measurements of Modern Bone Collagen
Dear Dr Eric Guiry,
Thank you for submitting your manuscript to Methods in Ecology and Evolution. I have now received the reviewers' reports and a recommendation from the Associate Editor who handled the review process. Copies of their reports are included below. As you will see, the reviewers are positive about the value of the work but have also made a number of suggestions for improvement. I have considered your paper in light of the comments received and I would like to invite you to prepare a minor revision.
In your revision, please make sure that you take full account of the above comments and those made in the reports below. Please note that Methods in Ecology and Evolution does not automatically accept papers after revision, and an invitation to revise a manuscript does not represent commitment to eventual publication on our part. We will reject revised manuscripts if they are returned without satisfactory responses to the reviewers' comments. When returning the revised paper, please show point-by-point how you have dealt with the various comments in the appropriate section of the submission form.
Please return your revision by 16-Jun-2020. If you need longer, please let us know so we can update our system accordingly. Before resubmitting your manuscript, please read through the resubmission instructions below.
We look forward to hearing from you in due course.
Sincerely,
Dr Aaron Ellison
Senior Editor, Methods in Ecology and EvolutionReply to:
Ms India Stephenson
Methods in Ecology and Evolution Editorial Office
coordinator@methodsinecologyandevolution.orgAssociate Editor Comments to Author:
Associate Editor
Comments to the Author:
I would like to congratulate the authors for this nice work. I do not have any additions to the reviewers' comments.Reviewer(s)' Comments to Author:
Reviewer: 1Comments to the Corresponding Author
The authors of this manuscript are to be congratulated on a monumental piece of work that pulls together a large body of research and draws a few simple put important conclusions.
The statistical treatments are appropriate and the use of figures/ tables effectively communicates the patterns within the data. The paper is extremely well written and I only found one possible typo:
line 348 “once helix is unwound” should probably read “once the helix is unwound”
My only criticism is that the title does not accurately reflect the content. The manuscript is not really about QC in stable isotope measurements but QC of collagen to be subject to stable isotope measurements. The authors should consider changing the title more accurately to reflect the content. Otherwise I am happy to recommend publication with no other changes.Reviewer: 2
Comments to the Corresponding Author
Dear editor
I have completed the review of the manuscript MEE-20-03-231, by Eric J. Guiry and Paul Szpak (Quality Control for Stable Carbon and Nitrogen Isotope Measurements of Modern Bone Collagen). The authors have undertaken a solid meta-analysis of amino acid and stable isotope data from a range of vertebrate classes (mammal, fish, birds) to assess quality criteria in modern collagen samples, which is crucial for accurate sample interpretation. The work provides robust evidence on endogenous factors affecting modern collagen molecular and atomic composition, with important implications for stable carbon isotope values (lipids, non-collagen proteins). They also critically discuss the effect of distinct collagen extraction protocols for both modern and ancient samples. I am convinced this paper will be a solid reference for future studies. The work is a valuable contribution to a wider community of scientists working on collagen stable isotope analysis, and as such I recommend it for publication in Methods in Ecology and Evolution. A few minor edits are listed below:
Symbols are missing in pages 11 and 17, lines 205 and 347 respectively
Replace table 3 for table 4 in page 133, line 254
I recommend checking the paper by Sealy et al., 2014 (Comparison of two methods of extracting bone collagen for stable carbon and nitrogen isotope analysis: comparing whole bone demineralization with gelatinization and ultrafiltration) where they compare distinct extraction methods including the results from ultrafiltration and non-ultrafiltration using NaOH. I think this paper should be acknowledged.Decision letter by
Cite this decision letter
Reviewer report
2020/05/22Dear editor
I have completed the review of the manuscript MEE-20-03-231, by Eric J. Guiry and Paul Szpak (Quality Control for Stable Carbon and Nitrogen Isotope Measurements of Modern Bone Collagen). The authors have undertaken a solid meta-analysis of amino acid and stable isotope data from a range of vertebrate classes (mammal, fish, birds) to assess quality criteria in modern collagen samples, which is crucial for accurate sample interpretation. The work provides robust evidence on endogenous factors affecting modern collagen molecular and atomic composition, with important implications for stable carbon isotope values (lipids, non-collagen proteins). They also critically discuss the effect of distinct collagen extraction protocols for both modern and ancient samples. I am convinced this paper will be a solid reference for future studies. The work is a valuable contribution to a wider community of scientists working on collagen stable isotope analysis, and as such I recommend it for publication in Methods in Ecology and Evolution. A few minor edits are listed below:
Symbols are missing in pages 11 and 17, lines 205 and 347 respectively
Replace table 3 for table 4 in page 133, line 254
I recommend checking the paper by Sealy et al., 2014 (Comparison of two methods of extracting bone collagen for stable carbon and nitrogen isotope analysis: comparing whole bone demineralization with gelatinization and ultrafiltration) where they compare distinct extraction methods including the results from ultrafiltration and non-ultrafiltration using NaOH. I think this paper should be acknowledged.Reviewed by
Cite this review
Reviewer report
2020/04/27The authors of this manuscript are to be congratulated on a monumental piece of work that pulls together a large body of research and draws a few simple put important conclusions.
The statistical treatments are appropriate and the use of figures/ tables effectively communicates the patterns within the data. The paper is extremely well written and I only found one possible typo:
line 348 “once helix is unwound” should probably read “once the helix is unwound”
My only criticism is that the title does not accurately reflect the content. The manuscript is not really about QC in stable isotope measurements but QC of collagen to be subject to stable isotope measurements. The authors should consider changing the title more accurately to reflect the content. Otherwise I am happy to recommend publication with no other changes.Reviewed by
Cite this review
