Limits...
Mixed signals? Morphological and molecular evidence suggest a color polymorphism in some neotropical polythore damselflies.

Sánchez Herrera M, Kuhn WR, Lorenzo-Carballa MO, Harding KM, Ankrom N, Sherratt TN, Hoffmann J, Van Gossum H, Ware JL, Cordero-Rivera A, Beatty CD - PLoS ONE (2015)

Bottom Line: The study of color polymorphisms (CP) has provided profound insights into the maintenance of genetic variation in natural populations.Our results suggest that, while highly distinct and discrete wing patterns exist in Polythore, these "wingforms" do not represent monophyletic clades in the recovered topology.We discuss the implications of this polymorphism, and the potential evolutionary mechanisms that could maintain it.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Rutgers University, Newark, New Jersey, United States of America.

ABSTRACT
The study of color polymorphisms (CP) has provided profound insights into the maintenance of genetic variation in natural populations. We here offer the first evidence for an elaborate wing polymorphism in the Neotropical damselfly genus Polythore, which consists of 21 described species, distributed along the eastern slopes of the Andes in South America. These damselflies display highly complex wing colors and patterning, incorporating black, white, yellow, and orange in multiple wing bands. Wing colors, along with some components of the male genitalia, have been the primary characters used in species description; few other morphological traits vary within the group, and so there are few useful diagnostic characters. Previous research has indicated the possibility of a cryptic species existing in P. procera in Colombia, despite there being no significant differences in wing color and pattern between the populations of the two putative species. Here we analyze the complexity and diversity of wing color patterns of individuals from five described Polythore species in the Central Amazon Basin of Peru using a novel suite of morphological analyses to quantify wing color and pattern: geometric morphometrics, chromaticity analysis, and Gabor wavelet transformation. We then test whether these color patterns are good predictors of species by recovering the phylogenetic relationships among the 5 species using the barcode gene (COI). Our results suggest that, while highly distinct and discrete wing patterns exist in Polythore, these "wingforms" do not represent monophyletic clades in the recovered topology. The wingforms identified as P. victoria and P. ornata are both involved in a polymorphism with P. neopicta; also, cryptic speciation may have taking place among individuals with the P. victoria wingform. Only P. aurora and P. spateri represent monophyletic species with a single wingform in our molecular phylogeny. We discuss the implications of this polymorphism, and the potential evolutionary mechanisms that could maintain it.

Show MeSH

Related in: MedlinePlus

Comparison of the differing topologies among phylogenetic reconstructions.Simplified topologies are shown based on (A) morphological and (B) COI data, showing typical examples of each wing morph (center). Only males were included in these analyses. For full trees, see Fig 5 and S1 Fig. G. Note: (a) P. ornata was recovered as monophyletic (although with low, 9% bootstrap branch support) except for two specimens, which were recovered within P. victoria (see S1 Fig. G); (b) in B, some P. neopicta grouped with P. ornata, while others grouped with P. victoria.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4414280&req=5

pone.0125074.g007: Comparison of the differing topologies among phylogenetic reconstructions.Simplified topologies are shown based on (A) morphological and (B) COI data, showing typical examples of each wing morph (center). Only males were included in these analyses. For full trees, see Fig 5 and S1 Fig. G. Note: (a) P. ornata was recovered as monophyletic (although with low, 9% bootstrap branch support) except for two specimens, which were recovered within P. victoria (see S1 Fig. G); (b) in B, some P. neopicta grouped with P. ornata, while others grouped with P. victoria.

Mentions: While distinct pattern elements can be identified through our morphometric analyses, our phylogenetic results are less clear. When considering the phylogenetic analyses of the morphological dataset alone (Fig. G in S1 File), individuals sharing a common wingform generally form well-supported clades, reflecting the distinctness of the different wingforms. The greatest exception to this are the males of P. aurora, which are found to be paraphyletic with respect to the remaining species; this is perhaps due to the rather extreme variability in the color intensity of individuals in our analyses (see the 3 examples at the top of Fig 1), Two individual males of P. ornata clustered with P. victoria males in the morphological phylogeny; this is likely due to variation in the hindwing banding patterns and forewing color patterns. Our molecular phylogenetic analyses (Figs 2B and 7) and species delimitation analyses reveal that, for the Peruvian species studied here, there are some wingforms that correspond to well-defined species—such as P. spaeteri and P. aurora—while the wingforms associated with P. victoria, P. neopicta and P. ornata do not resolve well. P. victoria and P. ornata emerge in different locations within the tree, but have P. neopicta individuals contained within each of these two clades; a number of P. victoria and P. neopicta individuals cannot be separated at all, and this clade with its two wingforms is identified as a species in our delimitation analysis, albeit with low support. Other specimens of P. neopicta are indistinguishable from P. ornata, and these individuals are identified as a species with high support by our delimitation analysis. Further, our delimitation analysis suggests that, similar to the cryptic speciation within P. procera highlighted by Sánchez Herrera et al. (2010) and recovered in our own results (Fig 2B) we have a small clade of individuals from one site (Pozuzo 6) that, despite having the characteristic P. victoria wingform, are supported as a separate species from the other P. victoria. The lack of molecular separations between P. neopicta and P. victoria/P. ornata are at the heart of this lack of congruence between analyses. These preliminary analyses of the COI sequence suggest that a more extensive phylogenetic exploration may be necessary to elucidate species relationships.


Mixed signals? Morphological and molecular evidence suggest a color polymorphism in some neotropical polythore damselflies.

Sánchez Herrera M, Kuhn WR, Lorenzo-Carballa MO, Harding KM, Ankrom N, Sherratt TN, Hoffmann J, Van Gossum H, Ware JL, Cordero-Rivera A, Beatty CD - PLoS ONE (2015)

Comparison of the differing topologies among phylogenetic reconstructions.Simplified topologies are shown based on (A) morphological and (B) COI data, showing typical examples of each wing morph (center). Only males were included in these analyses. For full trees, see Fig 5 and S1 Fig. G. Note: (a) P. ornata was recovered as monophyletic (although with low, 9% bootstrap branch support) except for two specimens, which were recovered within P. victoria (see S1 Fig. G); (b) in B, some P. neopicta grouped with P. ornata, while others grouped with P. victoria.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4414280&req=5

pone.0125074.g007: Comparison of the differing topologies among phylogenetic reconstructions.Simplified topologies are shown based on (A) morphological and (B) COI data, showing typical examples of each wing morph (center). Only males were included in these analyses. For full trees, see Fig 5 and S1 Fig. G. Note: (a) P. ornata was recovered as monophyletic (although with low, 9% bootstrap branch support) except for two specimens, which were recovered within P. victoria (see S1 Fig. G); (b) in B, some P. neopicta grouped with P. ornata, while others grouped with P. victoria.
Mentions: While distinct pattern elements can be identified through our morphometric analyses, our phylogenetic results are less clear. When considering the phylogenetic analyses of the morphological dataset alone (Fig. G in S1 File), individuals sharing a common wingform generally form well-supported clades, reflecting the distinctness of the different wingforms. The greatest exception to this are the males of P. aurora, which are found to be paraphyletic with respect to the remaining species; this is perhaps due to the rather extreme variability in the color intensity of individuals in our analyses (see the 3 examples at the top of Fig 1), Two individual males of P. ornata clustered with P. victoria males in the morphological phylogeny; this is likely due to variation in the hindwing banding patterns and forewing color patterns. Our molecular phylogenetic analyses (Figs 2B and 7) and species delimitation analyses reveal that, for the Peruvian species studied here, there are some wingforms that correspond to well-defined species—such as P. spaeteri and P. aurora—while the wingforms associated with P. victoria, P. neopicta and P. ornata do not resolve well. P. victoria and P. ornata emerge in different locations within the tree, but have P. neopicta individuals contained within each of these two clades; a number of P. victoria and P. neopicta individuals cannot be separated at all, and this clade with its two wingforms is identified as a species in our delimitation analysis, albeit with low support. Other specimens of P. neopicta are indistinguishable from P. ornata, and these individuals are identified as a species with high support by our delimitation analysis. Further, our delimitation analysis suggests that, similar to the cryptic speciation within P. procera highlighted by Sánchez Herrera et al. (2010) and recovered in our own results (Fig 2B) we have a small clade of individuals from one site (Pozuzo 6) that, despite having the characteristic P. victoria wingform, are supported as a separate species from the other P. victoria. The lack of molecular separations between P. neopicta and P. victoria/P. ornata are at the heart of this lack of congruence between analyses. These preliminary analyses of the COI sequence suggest that a more extensive phylogenetic exploration may be necessary to elucidate species relationships.

Bottom Line: The study of color polymorphisms (CP) has provided profound insights into the maintenance of genetic variation in natural populations.Our results suggest that, while highly distinct and discrete wing patterns exist in Polythore, these "wingforms" do not represent monophyletic clades in the recovered topology.We discuss the implications of this polymorphism, and the potential evolutionary mechanisms that could maintain it.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Rutgers University, Newark, New Jersey, United States of America.

ABSTRACT
The study of color polymorphisms (CP) has provided profound insights into the maintenance of genetic variation in natural populations. We here offer the first evidence for an elaborate wing polymorphism in the Neotropical damselfly genus Polythore, which consists of 21 described species, distributed along the eastern slopes of the Andes in South America. These damselflies display highly complex wing colors and patterning, incorporating black, white, yellow, and orange in multiple wing bands. Wing colors, along with some components of the male genitalia, have been the primary characters used in species description; few other morphological traits vary within the group, and so there are few useful diagnostic characters. Previous research has indicated the possibility of a cryptic species existing in P. procera in Colombia, despite there being no significant differences in wing color and pattern between the populations of the two putative species. Here we analyze the complexity and diversity of wing color patterns of individuals from five described Polythore species in the Central Amazon Basin of Peru using a novel suite of morphological analyses to quantify wing color and pattern: geometric morphometrics, chromaticity analysis, and Gabor wavelet transformation. We then test whether these color patterns are good predictors of species by recovering the phylogenetic relationships among the 5 species using the barcode gene (COI). Our results suggest that, while highly distinct and discrete wing patterns exist in Polythore, these "wingforms" do not represent monophyletic clades in the recovered topology. The wingforms identified as P. victoria and P. ornata are both involved in a polymorphism with P. neopicta; also, cryptic speciation may have taking place among individuals with the P. victoria wingform. Only P. aurora and P. spateri represent monophyletic species with a single wingform in our molecular phylogeny. We discuss the implications of this polymorphism, and the potential evolutionary mechanisms that could maintain it.

Show MeSH
Related in: MedlinePlus