Convergent evolution of sexual dimorphism in species of the family Dolichopodidae (Diptera)

Selivanova

2022

Preprint

Sexually dimorphic structures (ornaments) on the legs are important diagnostic features for Dolichopus males, whereas females of those males are often morphologically similar and their species diagnostics is difficult. To assessing the relevance and feasibility of setting diagnostic characters for five sister species of the genus Dolichopus Latreille, 1796 (D. argyrotarsis, D. lineaticornis, D. pennatus, D. popularis, D. subpennatus) analysis of morphometric trait was used: comparison of wing shape by methods of geometric morphometry, as well as comparison of the ratios of the leg segments lengths. Comparative analysis of morphometric characters with molecular data made it possible to study the phylogenetic signal of male leg ornaments. It was shown for Dolichopus species, that modifications of the males middle legs occurred independently several times in the genus. In addition, the evolutionary pattern in the formation of similar ornaments was also associated with changes in the morphometric features of the legs and wings. Based on wing and legs morphometry, new diagnostic characters were proposed for females of the studied species group.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Morphometric characters in the taxonomic recognition of the species of Dolichopus pennatus group (Diptera: Dolichopodidae)

Selivanova

2022

Preprint

“…According to published data, males use ornamented legs in courtship rituals [Sivinski, 1997]. Similar patterns of sexual behavior could arise independently in different taxonomic groups and lead to the formation of a similar combination of morphological characters [Bonduriansky, 2006;Chursina, 2019]. It is critical to examine such characters is important for construction of robust phylogenetic hypothesis, since in the case of convergent evolution, such structures do not reflect the phylogenetic closeness of species.…”

Section: Discussionmentioning

confidence: 99%

Morphometric characters in a taxonomic diagnosis of Dolichopus pennatus species group (Diptera: Dolichopodidae)

Selivanova

2022

euroasentj

Sexually dimorphic structures (ornamentation) on the legs are important diagnostic features for Dolichopus males, whereas females are often morphologically similar and therefore species diagnosis is difficult. To assess the relevance and feasibility of setting diagnostic characters for five sister species of the genus Dolichopus Latreille, 1796, namely D. argyrotarsis, D. lineatocornis, D. pennatus, D. popularis and D. subpennatus, an analysis of morphometric trait was used. Comparison of wing shape by methods of geometric morphometry, and comparison of leg segment lengths ratio were studied. Comparative analysis of morphometric characters with molecular data made it possible to study the phylogenetic signal of male leg ornamentation. It was shown for Dolichopus, that modifications of the middle legs of males occurred independently in different species. In addition, the evolutionary pattern in the formation of similar ornaments was also associated with changes in the morphometric features of the legs and wings. Based on wing and leg morphometry, new diagnostic characters were proposed for females of the studied species group. Резюме. Признаки полового диморфизма, такие как модификация ног, являются важными диагностическими признаками самцов Dolichopus, в то время как самки видов часто сходны морфологически и их диагностика затруднена. Для оценки значимости различий между пятью сестринскими видами рода Dolichopus Latreille, 1796: D. argyrotarsis, D. lineatocornis, D. pennatus, D. popularis и D. subpennatus был использован анализ морфометрических признаков, включающий сравнение форм крыльев методами геометрической морфометрии, и соотношения длин члеников ног. Сравнительный анализ морфометрических показателей с молекулярными данными позволил изучить филогенетический сигнал модификаций ног самцов. Показано, что у видов Dolichopus модификации средних ног самцов возникали независимо несколько раз. Кроме того, эволюционный паттерн в формировании сходных украшений также был связан с изменением морфометрических признаков ног и крыльев. Самки D. lineatocornis, D. pennatus и D. subpennatus не могут быть разделены по форме крыла, а также слабо различаются по морфометрическим признакам ног.

“…The resulting wing shape variations can potentially contribute to a general phylogenetic hypothesis based on molecular data and traditional morphological characters. The presence of a phylogenetic signal in characters of a particular category is still under discussion (Bernasconi et al, 2007b; Chursina & Grichanov, 2019), since the emergence of similar structures can be explained not only by the evolutionary proximity of species, but also by convergent evolution, as described, for example, for characters of sexual dimorphism (Bonduriansky, 2006; Chursina, 2019).…”

mentioning

confidence: 99%

Phylogeny of the genus Dolichopus Latreille, 1796 and testing for phylogenetic signal in morphological characters and morphometric data

Grichanov

2022

Preprint

Four groups of characters were used to evaluate phylogenetic relationships among 50 species of the genus Dolichopus: 810 nucleotide characters (for cytochrome oxidase I), 18 continuous characters generated from a geometric morphometric analysis of wing shape, 12 relative characters of the leg morphometry and 42 traditional morphological characters. Subsequently, the common database was used to construct a phylogenetic genus tree and to study the presence of a phylogenetic signal in each group. In this study it was shown that the following characters have a significant phylogenetic signal: the thickening of the costal vein at the insertion point with R1, the color of the fore coxa, the presence of male secondary sexual characters on the forelegs, the color of the femora, the presence of long cilia on the hind femora, and the color of the lower postocular cilia. Traits of male wing shape, such us the relative position of the apex of M1+2, the location of the posterior cossvein, the origin of the radial veins, and the position of the anal vein base, also showed a high phylogenetic signal. In addition, in males, the relative lengths of the first segment of the fore and mid tarsi showed a clear correlation with molecular data, which were interconnected with the presence of males leg modifications. In females, morphometric traits exhibited a less significant phylogenetic signal than in males, although, in most cases, the same traits evinced a high phylogenetic signal.