Search

Resumen. Se registran por primera vez para Chile dos especies de coccinelidos palearticos: Scymnus (Scymnus ) interruptus (Goeze) y Scymnus ( Pullus ) suturalis Thunberg, siendo este el primer registro para America del Sur del subgenero Scymnus ( Scymnus ) Kugelann. Se entregan los registros de recolecta de cada especie, sus caracteristicas principales y diferencias con otras especies de Scymnus presentes en Chile. Se presume que ambas especies ingresaron y se establecieron en el pais casualmente, producto del trafico comercial y/o turistico.

[eng] One of the most fascinating aspects of birds is their capability of migrate from one area to another throughout the year. Unravelling the patterns and processes involved in the evolution of migration is paramount to understand the current biogeography, ecology and evolution of migratory birds. On this basis, the main aim of the present thesis was to extend the knowledge of the mechanisms involved in the evolution of bird migration. To achieve that two main sections are presented in this thesis. In the first one, the aims were to disentangle the patterns of evolution of migratory behaviour and the identifying the main factors that could play an important role in it, using Sylvia warblers as case of study. In the second section, we explored the climatic niche and the potential distribution of breeding and wintering ranges in the last glacial maximum (LGM) of trans-Saharan long migratory species, in order to unravel the changes in migratory behaviour. We explored the evolution of migration in Sylvia warblers as both a discrete and continuous character using ancestral state reconstruction methods. We recovered the basal node as migratory in most analyses, suggesting seven independent losses of migratory behaviour in Sylvia warblers. Both analyses performed with migration as discrete or continuous character recovered different probabilities of sedentariness or migratoriness in some conflicting nodes depending of the ASR elements used. This forced as to consider controversial hypotheses of evolution of migration in some clades that could evolved from migratory to sedentary in a very short period of time or going through a partial migratory status instead. We used phylogenetic comparative methods to assess whether the evolutionary patterns of migratory distances are correlated with several biometric, climatic and productivity variables in a phylogenetic context, using Sylvia warblers as a case study. Our results recover net primary productivity (NPP) in the breeding range and during the breeding season as the variable with stronger positive correlation with migratory distances. Several climatic variables show a correlation with the evolution of migration and among morphological variables, migratory lineages tend to have longer wings than sedentary ones. It is not possible to disentangle if NPP was a main driver in the evolution of bird migratory behaviour or a consequence of it, yet migration and NPP seem to be tightly related today and along their evolutionary history. Migratory birds occupy different geographic areas during breeding and wintering periods and are exposed to different factors. One of those factors is the climatic component of the niche. We tested if migratory birds display similar climatic conditions in both breeding and wintering areas, using 355 bird migratory species from Eurasian to Africa flyways. Our results show that there is not climatic niche overlap between both ranges. This suggests that the climatic niche of most Euro-African migratory species is larger than expected. Given these results, both breeding and wintering climatic data need to be considered when performing species distribution models, to incorporate the total width of the climatic niche. During the Plio-Pleistocene, glacial cycles have shaped Northern Hemisphere birds' distributions that could result in changes in their migratory behaviour. In this context, it has been suggested that long-distance North American migratory species could have lost their migratory condition during cold periods regaining it later in warmer periods. We tested this hypothesis in Eurasian-African extant migratory bird species. We modelled present and LGM distribution of 80 trans-Saharan bird migratory species and we revised the available fossil record. Our results show a southwards reduction of the breeding distributions during the LGM compared to the present and similar wintering areas in the present and Pleistocene, with the Saharan belt gap always present through time. These results and the Pleistocene fossils from Africa not support the hypothesis of a loss of migratory condition in these species., [spa] Uno de los aspectos más fascinantes dentro de la ornitología es el estudio de la migración. Saber cuáles son los patrones y procesos implicados en la evolución de la migración, permite descubrir tanto componentes ecológicos, biogeográficos como evolutivos dentro las aves. Por ello, en esta tesis se pretende aumentar el conocimiento acerca de los mecanismos implicados en la evolución de la migración en algunas aves. Por un lado, se investigó cómo evolucionó la migración y qué factores pueden actuar como motores de su evolución en un contexto filogenético usando el género Sylvia como caso de estudio. Encontramos que los procesos de cambio en el comportamiento migratorio ocurrían siempre de migratorio a sedentario, siendo el antecesor del género también migratorio. Esto supone que probablemente el coste de pasar de migratorio a sedentario es menor que al revés. Además, evaluando si factores como el clima, la morfología o la productividad eran importantes en la evolución de la migración en el género Sylvia, encontramos que la productividad juega un papel muy importante. Esto supone que probablemente las especies comenzaron a migrar aprovechando los picos de productividad que surgen en latitudes medias durante la época de cría. Por otro lado, se investigó la evolución de la migración en un contexto biogeográfico y macrecológico utilizando especies migratorias Euro-Africanas. Primero se evaluó si las especies migratorias están sometidas a las mismas condiciones climáticas tanto en las zonas de cría como en invernada. Si fuera así, las especies migratorias podrían moverse guiándose o en busca de condiciones similares a lo largo de todo el año. Sin embargo, encontramos que no es así y por lo tanto las especies migratorias presentan un nicho climático mayor de lo esperado que es necesario tener en cuenta a la hora de hacer modelos de distribución. Considerando esto, realizamos modelos de distribución de especies transaharianas tanto en el presente como durante el último glacial máximo. En este caso queríamos descubrir si las especies seguían migrando cuando parte del Paleártico estaba cubierto de nieve, o si se hicieron sedentarias como se ha sugerido para especies migratorias norteamericanas. Nuestros resultados, junto con el registro fósil consultado, no apoyan que las especies dejaran de migrar, sino que probablemente redujeran sus distancias migratorias.

[spa] En la primera parte de la tesis, intentamos comprobar la idea generalizada de que la vegetación determina las características de la comunidad de mariposas, para lo cual realizamos una investigación en un área geográfica concreta (macizo del Montseny, Cataluña, NE de la Península Ibérica) en tres fases: catálogo de las especies presentes de mariposas y estimas de su abundancia, inventarios de las plantas y análisis estadístico comparativo. El estudio detallado de la taxocenosis de papilionoideos permitió establecer una gran coincidencia en el voltinismo y la fase de hibernación entre las especies filogenéticamente más próximas. Por el contrario, no encontramos una correspondencia clara entre la composición específica de la taxocenosis de mariposas y la de plantas, por lo que descartamos que los lepidópteros tengan una dependencia determinista de la vegetación y que la tipología de la vegetación sea predictiva respecto al poblamiento de mariposas. Ello probablemente se debe a que las plantas que establecen un vínculo funcional específico con los lepidópteros, básicamente las que sirven de alimento a las orugas monófagas son muy pocas. En la segunda parte de la tesis exploramos otra hipótesis del Dr. Margalef, según la cual la duplicación del número de células del ala de los lepidópteros, y por lo tanto de su superficie, podía ser un mecanismo de evolución y diversificación de este grupo. En primer lugar, contamos las escamas de cuatro ejemplares de distinto tamaño de Colias crocea, detectando una notable heterogeneidad en su distribución, pero comprobando a la vez que la densidad de escamas era independiente del tamaño. Por lo tanto, un aumento de tamaño del ala implicaba un proporcional mayor número de escamas, así como de las células que las generan. Este recuento de escamas se extendió a 127 especies de diferentes subfamilias, comprobando la generalidad de la afirmación anterior. Longitud alar y número de escamas siguen una relación alométrica que varía entre subfamilias, pero es homogénea para las distintas especies dentro de una subfamilia. En general, las subfamilias de especies más pequeñas presentan una alometría positiva (el número de escamas se incrementa con más rapidez), y las de mayor tamaño, negativa. Finalmente, analizamos las longitudes alares medias de 263 papilionoideos del Paleártico Occidental, separadamente para cada una de sus 11 subfamilias (las de 3 especies o más). La distribución de tamaños es agregada, y la agregación se produce alrededor de valores que se ordenan en una progresión de razón √2, que es la que corresponde a una potencial duplicación de la superficie alar. Asimismo, los resultados de un modelo matemático que simulaba la evolución del tamaño alar se ajustaban mucho mejor a las distribuciones empíricas cuando existía una cierta probabilidad de duplicación que cuando no. Las distribuciones de tamaños observados son compatibles, por lo tanto, con las duplicaciones que proponemos como hipótesis. Estas duplicaciones serían sucesos poco frecuentes en la historia evolutiva que generarían discontinuidades en la distribución de tamaños alares. Una vez producida la duplicación podrían producirse nuevos fenómenos de especiación por procesos evolutivos graduales con pequeñas variaciones alrededor de la dimensión alcanzada. Así pues, la evolución del tamaño alar sería fruto de la superposición de un modelo discontinuo de macroevolución y de un modelo más progresivo y continuo, más cercano a la microevolución, y constituiría, en definitiva, un mecanismo relevante de diversificación dentro del grupo., [eng] In the first part of the thesis we address the notion that the vegetation determines the characteristics of the butterfly community. To do so, we studied in depth a specific area (Montseny mountains, Catalonia, NE Iberian Peninsula), including censuses of butterflies, inventories of vegetation and comparative statistical analysis. Our results do not confirm a deterministic dependence of butterflies on vegetation. Most likely, butterflies and plants are not interrelated as assemblages, and the functional links are rare and very specific, i.e. plants that are used as food by monophagous larvae. In the second part, we explore a hypothesis put forward by Dr. Margalef, according to which the duplication of wing surface could be a mechanism implied in the evolution of Lepidoptera. To do this, we first analysed the variability of scales distribution, at both the intraspecific and interspecific levels, and we concluded that the density of scales did not vary with size, or, in other words, larger wings do not have larger scales, but a higher number of scales. Wing length and the number of scales show allometric relationship, and the allometric coefficients differ significantly between subfamilies. We then compiled data on wing lengths of 263 species of Papilionoidea separately for each subfamily. The distribution of wing lengths shows a high aggregation around values that are ordered in a progression of ratio √2. Moreover, we used a numerical simulation model of the wing length evolution to obtained a series of distributions of this parameter. These distributions fitted much better to the empirical ones when a certain probability of duplication of the wing surface was included in the model. These results, compatible with the duplication hypothesis, suggest that such duplications would be infrequent events generating discontinuities in the distribution of wing lengths. Thus, we propose that the evolution of wing size is the result of the overlapping of a discontinuous model (macroevolution) and a more progressive and continuous (microevolution) model, which together would produce speciation and diversification in the evolutionary process.

CHAPTER 1: Reconstructing ancient Mediterranean crossroads in Deronectes diving beetles Aim: To reconstruct the evolutionary history of a genus of freshwater beetle with a pan- Mediterranean distribution, to test classic hypotheses which proposed a Miocene origin for groups with high biodiversity in the Iberian and Anatolian peninsulas. Location: Mediterranean basin. Methods: We sequenced four mitochondrial and one nuclear gene from 51 specimens of 30 of the c. 60 extant species of Deronectes (Dytiscidae), all typical of mid-mountain streams from North Africa and Iberia over most of Europe to the Middle East. We used maximum likelihood, Bayesian probabilities with an a priori evolutionary rate and a dispersal–extinction–cladogenesis model to reconstruct their biogeographical history. Results: Deronectes has two major lineages which originated in the mid Miocene; one including mostly eastern and another mainly western and central Mediterranean species. From these two areas, range expansions, mainly at the end of the Miocene and beginning of the Pliocene, resulted in the many species groups and some of the extant species of the genus. Most of the current diversity and distributions are, however, of Plio-Pleistocene origin, particularly in widespread European species. Main conclusions: In line with traditional hypotheses, we found an ancient division between eastern and western Mediterranean lineages of Deronectes, likely resulting from the isolation of Europe west of the Alps from the Balkans and Anatolia during the early-middle Miocene. The history of the genus was strongly influenced by major geological and climatic events, with successive cycles of fragmentation and subsequent eastward and westward range expansions, resulting in a steady accumulation of species across the basin. Most of these range movements took place through the north side of the Mediterranean, with only local displacements in the south during the Messinian salinity crisis and a recent (Pleistocene) colonization of the Italian Peninsula, which remained largely submerged through most of the genus’ evolutionary history. CHAPTER 2: The origin of widespread species in a poor dispersing lineage (diving beetle genus Deronectes) In most lineages most species have restricted geographic ranges, with only few reaching widespread distributions. How these widespread species reached their current ranges is an intriguing biogeographic and evolutionary question, especially in groups known to be poor dispersers. We reconstructed the biogeographic and temporal origin of the widespread species in a lineage with particularly poor dispersal capabilities, the diving beetle genus Deronectes (Dytiscidae). Most of the ca. 60 described species of Deronectes have narrow ranges in the Mediterranean area, with only four species with widespread European distributions. We sequenced four mitochondrial and two nuclear genes of 297 specimens of 109 different populations of the four lineages of Deronectes including widespread species, together with their closest narrow range relatives, covering their entire distributions. Using Bayesian probabilities with an a priori evolutionary rate we performed (1) a global phylogeny/phylogeography to estimate the relationships of the main lineages within each group and root them, and (2) demographic analyses of the best population coalescent model for each species group, including a reconstruction of the geographical history estimated from the distribution of the sampled localities. We also selected 56 specimens to test for the presence of Wolbachia, a maternally transmitted parasite that can alter the patterns of mtDNA variability. All species of the four studied groups originated in the southern Mediterranean peninsulas and were estimated to be of Pleistocene origin. In three of the four widespread species the central and northern European populations were nested within those in the northern areas of the Anatolian, Balkan and Iberian peninsulas respectively, suggesting a range expansion at the edge of the southern refugia. In the Mediterranean peninsulas the widespread European species were replaced by vicariant taxa of recent origin. The fourth species (D. moestus) was proven to be a composite of unrecognised lineages with more restricted distributions around the Western and Central Mediterranean. The analysis of Wolbachia showed a high prevalence of infection among Deronectes, especially in the D. aubei group, where all sequenced populations were infected with the only exception of the Cantabrian Mountains, the westernmost area of distribution of the lineage. In this group there is a phylogenetic incongruence between the mitochondrial and the nuclear sequence, although not clear pattern links this discordance to the Wolbachia infection. Our results suggest that in different glacial cycles populations that happened to be at the edge of the newly deglaciated areas took advantage of the optimal ecological conditions to expand their ranges to central and northern Europe. Once this favourable ecological window ended populations become isolated, resulting in the presence of closely related but distinct species in the Mediterranean peninsulas. CHAPTER 3: Pleistocene range expansions in Western Palaearctic aquatic Coleoptera The Quaternary glacial cycles lead to large changes in the size and location of the geographic distribution of many species. During glacial maxima large areas of central and northern Europe become inhospitable to temperate species, which are generally assumed to have been recolonized by range expansions from Mediterranean refugia in the interglacials. An alternative possibility is that the recolonization was from non-Mediterranean sources, from glacial refugia in central Europe or western Asia, but data are still scarce concerning the origin of the central and north European species with very large geographic distributions, especially for insects. In this work we studied some species of three wide distributed lineages of freshwater beetles (Platambus maculatus complex, H. gracilis complex, and the genus Oreodytes), all typical of running waters and including both narrowly distributed southern endemics and widespread European species, some with distributions spanning the whole Palearctic. The main goal was to understand the role of the Pleistocene glaciations in the diversification and current distribution of these species. For this we sequenced four mitochondrial and two nuclear genes of 212 specimens of 107 different populations of the different lineages and used Bayesian probabilities and Maximum Likelihood to reconstruct the phylogenetic relationships, age and geographical origin of the western Palaearctic species of these three widely distributed lineages. All species of the three studied groups were estimated to be of Pleistocene origin. In the H. gracilis complex, a secondary fast range expansion from northern Anatolian populations to western and northern Europe resulted in the current widespread European H. gracilis. However, in the other two groups we found widespread central and northern European species the origin of which was not the Mediterranean area but central Asia, but with peripheral isolated forms in the southern Mediterranean peninsulas. These peripheral forms could have been confined as remnants of earlier diversification cycles or be result of incipient isolation of the most recent post-glacial expansion. The accumulation of narrow endemics of these lineages in the Mediterranean may thus be the result of successive cycles of range expansions with subsequent speciation (and local extinction in glaciated areas) through the multiple Pleistocene glacial cycles. CHAPTER 4: Range expansion and ancestral niche reconstruction in the Mediterranean diving beetle genus Meladema (Coleoptera, Dytiscidae) Species of the genus Meladema (Dytiscidae, Colymbetinae) are some of the largest macroinvertebrates in the western Palearctic region, being top predators in fishless streams. Two of the three described species, M. imbricata (Wollaston, 1871) and M. lanio (Fabricius, 1775) are Macaronesian endemics from the Canary Islands and Madeira respectively, while the third, M. coriacea Laporte, 1835, is widely distributed from Morocco and the Iberian Peninsula to Turkey, including the Canary Islands. Previous phylogenetic analysis using only mitochondrial markers revealed the existence of two cryptic lineages within M. coriacea, one restricted to Corsica and the other including the rest of sampled populations. We reconstruct here the evolutionary history of the species of Meladema using a more comprehensive sampling covering its whole geographical range, adding nuclear markers and Bayesian molecular dating. Using environmental niche modelling we test for possible differences in climatic preferences among lineages, and reconstruct their ancestral climatic niche. Our results strongly supported the existence of four monophyletic lineages represented by the three recognised species plus a fourth cryptic lineage with populations of M. coriacea from the Tyrrhenian islands (Corsica, Sardinia and Montecristo). This pattern is not likely to be the result of mitochondrial artefacts due to Wolbachia infection, as all 11 tested individuals were negative for this parasite. Dating analysis placed the origin of Meladema in the Middle Miocene although diversification among extant Meladema lineages started in the early Pleistocene and took place in a relatively short time period. Phylogeographic analysis inferred a continental origin of Meladema, with an independent colonization of the Macaronesian and Mediterranean islands. From the southwestern Mediterranean region the continental M. coriacea expanded its range up to Turkey in the northern basin, and to Tunisia in the southern. Results of niche modelling showed that seasonality is the critical factor in shaping the current distribution of Meladema. Island lineages (M. imbricata, M. lanio and the Thyrrenian lineage of M. coriacea) occur in sites with low seasonality, within the range of the reconstructed ancestral climatic niche of the genus. On the contrary, continental M. coriacea expanded its range to localities outside the ancestral climatic range of the genus, with a higher seasonality and aridity., Una pregunta básica sobre los rangos geográficos es comprender por qué unas especies están ampliamente distribuidas mientras otras, estrechamente emparentadas tienen distribuciones restringidas. En este estudio pretendo comprender los factores que llevaron a algunas especies a expandir su rango original y sugerir posibles hipótesis que expliquen las enormes diferencias de rango entre especies emparentadas. Para ello, reconstruyo la historia evolutiva de varios linajes de coleópteros acuáticos del Paleártico Occidental bajo el contexto de la compleja historia geológica y climática de este área, con el fin de aclarar los procesos que han contribuido a la actual distribución de especies en estos grupos. Estos linajes son típicos de aguas corrientes (es decir, con baja capacidad dispersiva) e incluyen tanto endemismos distribuidos en pequeñas áreas, como especies de amplia distribución, mostrando su potencial de expansión de rango. Las reconstrucciones biogeográficas llevadas a cabo sugieren la existencia de varios eventos de expansión de rango entre la zona oriental y occidental de la Cuenca Mediterránea bajo condiciones favorables, seguidos de fragmentación cuando las condiciones empeoraban. Estas expansiones debieron producirse principalmente a lo largo de la costa norte del Mediterráneo, ya que por la sur hay ausencia de especies al este de Túnez. A pesar de que no es posible establecer un origen temporal común para los grupos estudiados, el Mioceno con sus múltiples conexiones entre el Mediterráneo occidental y oriental seguidas de aislamiento, parece estar implicado en el origen y disyunción este-oeste en varios grupos. Sin embargo, la mayor parte de las especies actuales se originaron durante el Pleistoceno, incluyendo aquellas que han alcanzado amplias distribuciones, siendo por tanto la época mas influyente en la distribución actual de especies. Las sucesivas rondas de expansión y fragmentación de rango resultaron principalmente en la acumulación de especies restringidas en el área Mediterránea, especialmente en Anatolia y la Península Ibérica. A pesar de la evidencia en muchos casos de especiación con estabilidad de rango dentro del área Mediterránea, algunas especies lograron expandir su rango original hasta alcanzar amplias distribuciones en áreas mas al norte, probablemente aprovechando una posición geográfica ventajosa cuando las condiciones ambientales fueron ventajosas. No obstante, diferencias en tolerancia fisiológica y/o ecológica también pudieron favorecer las expansiones de rango en unas especies y limitarlo en otras, aunque futuras investigaciones experimentales se requieren para poder testar esta hipótesis.