This MS deals with a detailed study on two European newts, where the pattern of morphological variables (including quantitative and qualitative measures of skin colour) are studied in several geographical distant populations (including allopatric and sympatric distributions). Several physical variables were also obtained in each locality and so they studied whether the pattern of species differences can be attributed to either environmental gradients or species distribution (allopatry/sympatry). The results points to a complex trend of the different variables, many showing convergence in sympatry, suggesting accommodation to local or climatic conditions (in addition to other possibilities) while others diverge in sympatry as a consequence of (most probably) character displacement. The study is descriptive, but the number of studied population, individuals and traits as well as the statistical methods used in the analyses could partially attributed the effects to different factors. The study provides new possible alternative scenarios with several new potential suggestive hypothesis with specific predictions that can be the origin of further scientific effort in this model system. Therefore the study seems valuable and interesting for JEB and it could be publishable. I found however a few potential complications that should be revised before acceptation.
. Line 98. helveticus instead of heveticus.
. Lines 116- 138 vs Table 1. The authors used many variables but often they are mentioned by different names. For example it is difficult to follow the name of variables in this paragraph compared to the denomination of the same variables in Table 1. More caution is needed using always the same nomenclature to describe the variables.
. Table 1. Furthermore, to clarify further this table a new column indicating whether the trait is or not a sexual trait should be desirable too. The table legend says that most are sexual ornaments is that the same that they are sexual traits? Clarify nomenclature again.
. Lines 146-154. The study used 55 sites, but they are not described formammly nor in text or supplementary material. This is important and the name of sites as well as GPS coordinates should appear, as well as sample size of every species. Perhaps this paragraph could be summarized with a new table in supplementary material.
. Figure S1. This figure seems to me central to the MS and it should be replaced in the text as Figure 1, renumbering the others.
. Lines 180-204. I find insufficient to mention that colour variables are described in Montgomery 2006. The algorithms used should appear described in a table at supplementary material too.
. Lines 245-258. This can be a key problem, if it is not clear enough how the convergence/divergence index is calculated. Do they use the absolute species difference in allopatry minus the absolute species difference in sympatry or the opposite? Perhaps a mathematical formulae would be desirable too. The text is not clear here, and several results in the text below are somehow confusing too, I assume here that they use coefficient = A(BSOLUTE)D(IFFERENCE)sympatry – ADallopatry (see Figure 3).
. Line 313. Use 9 male and 6 female instead of 10 and 6 (see that you placed a bold probability in a non significant case in table S1, see belly S1_UV Pr value).
. Lines 352-356. Describe explicitly the calculus made on Figure 2 (Index=0.5(ADsym)-0.75(ADallop)= -0.05, as I assume here).
. Lines 358-366. The description is right here, but the sentence could be confusing. Assuming the former index (-3.19) means that differences between species I allopatry are much larger than differences between species in sympatry (characteristic of convergence), but the last sentence in the paragraph is confusing just because it is expressed in terms of similarity rather than differentiation, as it has been described the index and rest of text. Rephrase the sentence in terms of differentiation, please.
. Lines 379-393. Check the name of variables described in text and Figure 4, it is not possible to identify the names in text and figures simultaneously. This is a complex MS with several morphological an environmental variables, revise the naming along the whole text. Furthermore, belly (in Figure & Tables) is a synonymous of ventral (in text) but in a way to simplify the understanding, use exclusively one of them.
. Lines 557-560. This paragraph seems to me relevant in introduction to justify the MS design, it should be correspondingly replaced. Perhaps in introduction it should be also emphasized that this study is of descriptive nature, but rather useful to explore contrasting interpretations that can be a posterior confirmed by more manipulative experimentation, or something similar.