PONE-D-20-37019

Isotopic evidence for geographic heterogeneity in Ancient Greek military forces

PLOS ONE

Dear Dr. Reinberger,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

Reviewer 1:

The scientific merits of this paper include the investigation of geographic origins in individuals buried after two Greek battles in the Greek Sicilian colony of Himera using strontium and oxygen isotopes. The dataset is a welcome contribution to the use of isotopic data to infer geographic origins. I think it is particularly important to have examples like this one, where the authors successfully incorporate Greek historical documents with bioarchaeological data in an appropriately contextualized bioarchaeological project.

The research questions, background sections, sample preparation and analysis are appropriate and the interpretations are reasonable and supported by the data. I only have minor suggestions to improve the paper. For example, the convention is usually to have a minimum of three sentences in each paragraph, and following Coplen, the delta symbol should be italicized throughout. Finally, given the accuracy and precision of the oxygen isotope data from the analyzed standards, the data should only be reported to the first decimal place, not the second.

Overall, I feel that the questions and methods addressed in this manuscript are beneficial to the body of literature on isotopic analyses in bioarchaeology. This manuscript was very interesting to read and I am happy recommend the manuscript for publication.

Reviewer 2

Overall, this is a very good study using scientific methods to test "historical" information. Very few strontium isotope analyses have been done yet in this area, however oxygen isotope values are available for many archaeological sites in Italy. One example for Sicily, for Greek site in Syracuse, is Tanasi et al. 2017 in  Science and Technology of Archaeological Research 3(2): 466-477.

Some minor questions just to elaborate on:

p. 3, line 58: was The Histories definitely written in 440 BCE, or “about” then?

p. 7, lines 150-151: here it says “revealed nine mass graves...” but then in the next sentence “Seven graves...and one.” So is it 8 or 9 in total?

p. 9, lines 181-182: Why are “shales and granites” older rocks, and “basalt” a younger rock? Doesn’t this specifically depend on the particular geographic location? The citations provided are not for Sicily or this area in particular.

p. 11, line 232-234: So of 132 total individuals, 70 didn’t have any teeth? (authors state that their sample is 100% of all having at least one tooth)

p. 13 - Table 1: I don’t think it is appropriate to have six decimal places for the Sr isotope ratio, since the values obtained on the standard NBS 987 have std in the 5th decimal place (p. 16, line 304).

p. 16, line 306: so you decided to use regular acetic acid rather than buffered, when the latter has been shown to be more consistent between labs and separate from particle size. Any particular reason?

p. 16, lines 313-315: was a different mass spec used for the water samples, or just a separate input to the same mass spec as the tooth samples?

Minor corrections:

p. 4, line 79: add space before “Greekness”

p. 5, line 108: should be a period after “Fig”

p. 7, line 146: need space after period and before “The”

p. 8, line 174: plural is “radii”, not “radiuses”

p. 9, line 190 & 192: should be a period after “Fig”

p. 9, line 192: Sentence could have better grammar, e.g. “..rocks are associated with the Mt. Etna...”

p. 10, line 202: add space bore “87Sr/86Sr”

p. 10, line 208: spell out “Fig” since it’s part of the sentence

p. 10, line 210: remove the underline under the period and space before “(52)”

p. 10, lines 219-224: add space before “mm” and before “C”, these are abbreviations for separate words (the degree symbol is not an abbreviation, so that stays with the temperature number)

p. 11, line 25: same

p. 11, line 242: change tense of “analyze” to “analyzed”

p. 12, line 246: same

p. 15, lines 285, 290, 301: add space before “C”

p. 15, line 290: remove space in “2 N” to be consistent with what you have elsewhere on the same page

p. 15, line 298: add spaces in both cases where you have “2ml”

p. 16, line 303: edit wording so you don’t have “following using”

p. 16, line 311: make the sentence better by starting “The mean d18O of the Fisher...”

p. 16, line 312: remove the second decimal place from the std dev “0.12"

p. 16, lines 310, 315, 319, 321, 322: the “v” in “vPDB” and “vSMOW should be capitalized

p 17, line 337: ditto (while in line 339 you do have it capitalized)

p. 17, line 334: shorten to 5 decimal places the Sr range

p. 17, line 341: delete “calculated” since it is in the next line of the sentence

p. 18, Table 3: change d18O isotope values to one decimal place; capitalize the “v” in column caption

p. 18, Table 3: change Sr decimal places to 5

p. 21, lines 349-350: be consistent in hyphen size and space before/after

p. 21, lines 349-350 & 356-357: be consistent and use 5 decimal places (not 4 or 6)

p. 22, line 30: again you have just 4 decimal places, is that particularly intentional?

p. 23, line 376: add something like “The dozen...” at the beginning of the sentence to reinform the reader how many individuals the data are based on

p. 23, line 377: you have average of 6 decimal places, std only 5

p. 23, line 380: add space between “d18O” and “value”, and make “18" superscript

p. 23, line 384: add space again

p. 23, line 392: after “values” add “which” and remove “s” from “supports” so it reads “...values which support literary...”

p. 23, line 394: reword beginning of sentence, e.g. to “This study provides evidence, however, for..”

p. 24, line 420: are “Sicels” the same as “Sikels”? Check if you mention either before this page

p. 25, line 443: change “offer” to past tense (offered)

p. 26, line 462: add space after period, before “Foreign”

p. 26, line 468: change semicolon to comma after “Stamer”

p. 28, ref. 1: remove the “Available from: ...”

p. 29, line 550: capitalize second initial for Ezzo, uncapitalize “Of” in journal name

p. 29, line 564: remove space before colon

p. 30, line 572: remove the “Available from: ...”

p. 30, line 585: remove the “Available from: ...”

p. 30, lines 609-10: capitalization of article title inconsistent with others, check the style expected.

p. 31, line 633: remove space after hyphen so that it reads “Look-Up”

p. 31, lines 635-7: remove the “Available from: ...”

Figure 3: the precision of the O isotope ranges should be consistent with decimal places, while given the precision of the measurements no more than 2 decimal places. Also the lower case “v”

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We look forward to receiving your revised manuscript.

Kind regards,

Mario Novak

Academic Editor

PLOS ONE

Additional Editor Comments:

Both referees agree that this is a very good paper that needs only some minor reworking to be acceptable for publication. I tend to agree with the reviewers and would suggest a minor revision based on their comments and suggestions.

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Reviewers' comments:

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Comments to the Author

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Reviewer #1: Yes

Reviewer #2: Yes

**********

2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

**********

3. Have the authors made all data underlying the findings in their manuscript fully available?

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Reviewer #1: Yes

Reviewer #2: Yes

**********

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Reviewer #1: Yes

Reviewer #2: Yes

**********

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Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: Review of “Isotopic Evidence for Geographic Heterogeneity in Ancient Greek Military Forces” by Reinberger et al. for PLOS One

The scientific merits of this paper include the investigation of geographic origins in individuals buried after two Greek battles in the Greek Sicilian colony of Himera using strontium and oxygen isotopes. The dataset is a welcome contribution to the use of isotopic data to infer geographic origins. I think it is particularly important to have examples like this one, where the authors successfully incorporate Greek historical documents with bioarchaeological data in an appropriately contextualized bioarchaeological project.

The research questions, background sections, sample preparation and analysis are appropriate and the interpretations are reasonable and supported by the data. I only have minor suggestions to improve the paper. For example, the convention is usually to have a minimum of three sentences in each paragraph, and following Coplen, the delta symbol should be italicized throughout. Finally, given the accuracy and precision of the oxygen isotope data from the analyzed standards, the data should only be reported to the first decimal place, not the second.

Overall, I feel that the questions and methods addressed in this manuscript are beneficial to the body of literature on isotopic analyses in bioarchaeology. This manuscript was very interesting to read and I am happy recommend the manuscript for publication.

Reviewer #2: Overall, this is a very good study using scientific methods to test "historical" information. Very few strontium isotope analyses have been done yet in this area, however oxygen isotope values are available for many archaeological sites in Italy. One example for Sicily, for Greek site in Syracuse, is Tanasi et al. 2017 in Science and Technology of Archaeological Research 3(2): 466-477.

Some minor questions just to elaborate on:

p. 3, line 58: was The Histories definitely written in 440 BCE, or “about” then?

p. 7, lines 150-151: here it says “revealed nine mass graves...” but then in the next sentence “Seven graves...and one.” So is it 8 or 9 in total?

p. 9, lines 181-182: Why are “shales and granites” older rocks, and “basalt” a younger rock? Doesn’t this specifically depend on the particular geographic location? The citations provided are not for Sicily or this area in particular.

p. 11, line 232-234: So of 132 total individuals, 70 didn’t have any teeth? (authors state that their sample is 100% of all having at least one tooth)

p. 13 - Table 1: I don’t think it is appropriate to have six decimal places for the Sr isotope ratio, since the values obtained on the standard NBS 987 have std in the 5th decimal place (p. 16, line 304).

p. 16, line 306: so you decided to use regular acetic acid rather than buffered, when the latter has been shown to be more consistent between labs and separate from particle size. Any particular reason?

p. 16, lines 313-315: was a different mass spec used for the water samples, or just a separate input to the same mass spec as the tooth samples?

Minor corrections:

p. 4, line 79: add space before “Greekness”

p. 5, line 108: should be a period after “Fig”

p. 7, line 146: need space after period and before “The”

p. 8, line 174: plural is “radii”, not “radiuses”

p. 9, line 190 & 192: should be a period after “Fig”

p. 9, line 192: Sentence could have better grammar, e.g. “..rocks are associated with the Mt. Etna...”

p. 10, line 202: add space bore “87Sr/86Sr”

p. 10, line 208: spell out “Fig” since it’s part of the sentence

p. 10, line 210: remove the underline under the period and space before “(52)”

p. 10, lines 219-224: add space before “mm” and before “C”, these are abbreviations for separate words (the degree symbol is not an abbreviation, so that stays with the temperature number)

p. 11, line 25: same

p. 11, line 242: change tense of “analyze” to “analyzed”

p. 12, line 246: same

p. 15, lines 285, 290, 301: add space before “C”

p. 15, line 290: remove space in “2 N” to be consistent with what you have elsewhere on the same page

p. 15, line 298: add spaces in both cases where you have “2ml”

p. 16, line 303: edit wording so you don’t have “following using”

p. 16, line 311: make the sentence better by starting “The mean d18O of the Fisher...”

p. 16, line 312: remove the second decimal place from the std dev “0.12"

p. 16, lines 310, 315, 319, 321, 322: the “v” in “vPDB” and “vSMOW should be capitalized

p 17, line 337: ditto (while in line 339 you do have it capitalized)

p. 17, line 334: shorten to 5 decimal places the Sr range

p. 17, line 341: delete “calculated” since it is in the next line of the sentence

p. 18, Table 3: change d18O isotope values to one decimal place; capitalize the “v” in column caption

p. 18, Table 3: change Sr decimal places to 5

p. 21, lines 349-350: be consistent in hyphen size and space before/after

p. 21, lines 349-350 & 356-357: be consistent and use 5 decimal places (not 4 or 6)

p. 22, line 30: again you have just 4 decimal places, is that particularly intentional?

p. 23, line 376: add something like “The dozen...” at the beginning of the sentence to reinform the reader how many individuals the data are based on

p. 23, line 377: you have average of 6 decimal places, std only 5

p. 23, line 380: add space between “d18O” and “value”, and make “18" superscript

p. 23, line 384: add space again

p. 23, line 392: after “values” add “which” and remove “s” from “supports” so it reads “...values which support literary...”

p. 23, line 394: reword beginning of sentence, e.g. to “This study provides evidence, however, for..”

p. 24, line 420: are “Sicels” the same as “Sikels”? Check if you mention either before this page

p. 25, line 443: change “offer” to past tense (offered)

p. 26, line 462: add space after period, before “Foreign”

p. 26, line 468: change semicolon to comma after “Stamer”

p. 28, ref. 1: remove the “Available from: ...”

p. 29, line 550: capitalize second initial for Ezzo, uncapitalize “Of” in journal name

p. 29, line 564: remove space before colon

p. 30, line 572: remove the “Available from: ...”

p. 30, line 585: remove the “Available from: ...”

p. 30, lines 609-10: capitalization of article title inconsistent with others, check the style expected.

p. 31, line 633: remove space after hyphen so that it reads “Look-Up”

p. 31, lines 635-7: remove the “Available from: ...”

Figure 3: the precision of the O isotope ranges should be consistent with decimal places, while given the precision of the measurements no more than 2 decimal places. Also the lower case “v”

**********

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Reviewer #1: No

Reviewer #2: No

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Isotopic evidence for geographic heterogeneity in Ancient Greek military forces

PONE-D-20-37019R1

Dear Dr. Reinberger,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

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Mario Novak

Academic Editor

PLOS ONE

Additional Editor Comments (optional):

Reviewers' comments: