87 research outputs found
Estudio filogenético de los géneros de Trichopterygini de Sudamérica Austral (Lepidoptera: Geometridae): una nueva clasifi cación
Phylogenetic study of the genera of South American Austral Trichopterygini (Lepidoptera: Geometridae, Larentiinae): a new classifi cation. In this work, we evaluate the taxonomy of the Trichopterygini in Chile based on a phylogenetic analysis of the morphological attributes. In our analysis, we used Tatosoma and Sauris as outgroups. Two approaches were used to evaluate phylogenetic relationships: 1) parsimony criterion, and 2) Bayesian inference. Parsimony analysis was conducted in PAUP software, and Bayesian analysis with Markov chain Monte Carlo using the BayesPhylogenies software. Our results based on the phylogenetic hypothesis suggest a new taxonomic order for Trichopterygini of the Andean Region of Southern South America. The valid genera are: Arrayanaria Parra, Butleriana Parra, Danielaparra Kemal & Kocak, Fueguina Parra, Hoplosauris Butler, Lagynopteryx Berg, Llampidken Parra & Santos-Salas, Pachrophylla Blanchard, Parapachrophylla Parra, Rindgenaria Parra, Tomopteryx Philippi, Triptila Warren, Triptiloides Parra & Santos-Salas, Warrenaria Parra. The main changes with respect to the previous taxonomic order are: 1) the genus Lagynopteryx Berg is subordinated under the Trichopterygini; 2) Toxopaltes Warren is a junior synonym of Lagynopteryx; 3) Hoplosauris moesta is transferred to the genus Llampidken; 4) Llampidken valdiviana is a junior synonym of L. moesta; 5) Oparabia arenosa is newly combined with the genus Arrayanaria; 6) Danielaparra viridis is a junior synonym of D. fragmentata; 7) Lobophoraimbricaria is newly combined with the genus Danielaparra; 8) Triptiloides fasciata is a junior synonym of T. randallae; and 9) Parapachrophylla michelleae Parra n. sp. is described. Andean Region species are more closely related to the genus Tatosoma from New Zealand, the synapomorphies that demonstrate this are: swollen metaepimeron and hypertrophy of the second abdominal segment. A checklist of the genera and species of the tribe in the region, and the fi gures of adults and genitalia of some species are included.En este trabajo se evalúa la taxonomía de los Trichopterygini de Chile a partir de un análisis fi logenético de los atributos morfológicos. En nuestro análisis, hemos utilizado Tatosoma y Sauris como grupos externos. Se utilizaron dos enfoques para evaluar las relaciones fi logenéticas: 1) criterio de parsimonia, y 2) inferencia bayesiana. El análisis de parsimonia se realizó a través del programa PAUP y el análisis bayesiano con cadenas de Markov y Monte Carlo a través del programa BayesPhylogenies. Nuestros resultados basados en la hipótesis fi logenética sugieren un nuevo orden taxonómico para Trichopterygini de la Región Andina del Sur de Sudamérica. Los géneros válidos son: Arrayanaria Parra, Butleriana Parra, Danielaparra Kemal & Kocak, Fueguina Parra, Hoplosauris Butler, Lagynopteryx Berg, Llampidken Parra & Santos-Salas, Pachrophylla Blanchard, Parapachrophylla Parra, Rindgenaria Parra & Santos-Salas, Tomopteryx Philippi,Triptila Warren y Warrenaria Parra. Los principales cambios con respecto al orden taxonómico anterior son: 1) el género Lagynopteryx Berg se incorpora a Trichopterygini; 2) Toxopaltes Warren es el sinónimo junior de Lagynopteryx; 3) Hoplosauris moesta se incorpora al género Llampidken; 4) Llampidken valdiviana es el sinónimo junior de L. Moesta; 5) Oparabia arenosa es incorporada al género Arrayanaria; 6) Danielaparra viridis es el sinónimo junior de D. fragmentata; 7) Lobophora imbricaria es incorporada al género Danielaparra; Triptiloides fasciata es el sinónimo junior de T. randallae; y 9) Parapachrophylla michelleae Parra n. sp. es descrita. Las especies de la Región Andina están más cerca del Tatosoma de Nueva Zelanda, las sinapomorfi as que demuestran esto son: el metaepimeron hinchado y la hipertrofia del segundo segmento abdominal. Se incluye un catálogo de los géneros y especies de la tribu en la región, y fotografías de adultos y armaduras genitales de algunas especies
Expensive Brains: “Brainy” Rodents have Higher Metabolic Rate
Brains are the centers of the nervous system of animals, controlling the organ systems of the body and coordinating responses to changes in the ecological and social environment. The evolution of traits that correlate with cognitive ability, such as relative brain size is thus of broad interest. Brain mass relative to body mass (BM) varies among mammals, and diverse factors have been proposed to explain this variation. A recent study provided evidence that energetics play an important role in brain evolution (Isler and van Schaik, 2006). Using composite phylogenies and data drawn from multiple sources, these authors showed that basal metabolic rate (BMR) correlates with brain mass across mammals. However, no such relationship was found within rodents. Here we re-examined the relationship between BMR and brain mass within Rodentia using a novel species-level phylogeny. Our results are sensitive to parameter evaluation; in particular how species mass is estimated. We detect no pattern when applying an approach used by previous studies, where each species BM is represented by two different numbers, one being the individual that happened to be used for BMR estimates of that species. However, this approach may compromise the analysis. When using a single value of BM for each species, whether representing a single individual, or available species mean, our findings provide evidence that brain mass (independent of BM) and BMR are correlated. These findings are thus consistent with the hypothesis that large brains evolve when the payoff for increased brain mass is greater than the energetic cost they incur
Evaluación sistemática del género Helcogrammoides (Blenniformes: Tripterygiidae): Pequeños peces con grandes problemas
La familia Tripterygiidae en las costas de Chile se encuentra representada por dos especies correspondientes al género Helcogrammoides; sin embargo, éstas fueron originalmente descritas en el género Tripterygion el cual se distribuye actualmente en el Mar Mediterráneo y en el noreste del océano Atlántico. En 1959, Rosenblatt reconoce las diferencias entre estas y las demás especies del género Tripterygion, proponiendo el género Helcogrammoides. En la actualidad la hipótesis taxonómica no ha sido evaluada en base a aproximaciones sistemáticas filogenéticas que permitan considerar la validez evolutiva de esta propuesta. A la fecha el único análisis comparativo realizado con otras especies de la familia utilizó caracteres morfológicos y sugiere que Helcogrammoides pertenecería a la tribu Karalepini junto al género monotípico Karalepis, tribu considerada como monofilética en base a las sinapomorfías morfológicas. En este trabajo se evalúa la hipótesis taxonómica de Rosenblatt y la monofilia de la tribu Karalepini mediante aproximaciones filogenéticas basadas en datos moleculares y morfológicos. Los resultados sugieren que el género Helcogrammoides es un género monofilético que difiere de Tripterygion tanto morfológica como molecularmente, respaldando la hipótesis de Rosenblatt. A su vez el análisis filogenético molecular, y de datos moleculares y morfológicos concatenados, agrupan el género Karalepis junto al género Tripterygion en un clado separado del género Helcogrammoides, refutando la monofilia de la tribu Karalepini y sugiriendo que los caracteres morfológicos que sustentaban la tribu podrían corresponder a homoplasias que oscurecen los resultados del análisis morfológico basado en el criterio de parsimonia y que explican la baja probabilidad a posteriori de este clado en el análisis Bayesiano
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The origin and correlated evolution of symbiosis and coloniality in Scleractinian corals
Symbiosis and coloniality are ecologically important traits for corals of the order Scleractinia. Symbiotic (zooxanthellate) species are highly successful in shallow waters of tropical and subtropical seas and most of them are colonial. On the other hand, azooxanthellate species present wide distribution ranges and expand to the deep-sea at more than 6,000 m depth. These are mostly solitary, with only few species colonial that form extensive deep reefs. Each ecologically distinctive group encompasses half of the biodiversity of the order and they are not grouped into differentiated monophyletic clades. Paleontologists and evolutionary biologists have debated for decades whether modern scleractinian corals have evolved from symbiotic or colonial ancestors and how these traits have evolved and being involved in the diversification process in corals. Previous comparative analyses throw evidence in favor of coevolution of these characters and toward repetitive loss of symbiosis and coloniality. Nevertheless, the discovery of the origin of the group deep in the Paleozoic, with a deep divergent clade composed of only azooxanthellate corals has questioned these findings. With this work, we disentangle the patterns in the evolution of symbiosis and coloniality, testing if they are correlated and if they follow a gradual or episodic mode of evolution. To this end, we first produce the most complete time-calibrated phylogenetic tree for the order Scleractinia, including new sequences of never-before sampled species and genera. These novel sequences contribute to alleviate the current molecular under sampling of azooxanthellate species. Incorporating phylogenetic uncertainty, we obtained strong evidence in favor of a correlated and episodic model of evolution. This model led to the inference of an azooxanthellate and solitary most recent ancestor of scleractinians. Transition rates between the four different combinations of the two traits showed that while coloniality is gained and lost multiple times, symbiosis first appears around 282 Ma and is never lost. Also, coloniality seems to have appeared before symbiosis in azooxanthellate lineages. Thus, azooxanthellate corals, and especially colonial lineages, have been acting as a source of biodiversity for shallow zooxanthellate coral communities, highlighting the uniqueness of shallow and deep species and the need to preserve them
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Deep-sea origin and depth colonization associated with phenotypic innovations in scleractinian corals
The deep sea (>200 m) is home to a surprisingly rich biota, which in some cases compares to that found in shallow areas. Scleractinian corals are an example of this - they are key species in both shallow and deep ecosystems. However, what evolutionary processes resulted in current depth distribution of the marine fauna is a long-standing question. Various conflicting hypotheses have been proposed, but few formal tests have been conducted. Here, we use global spatial distribution data to test the bathymetric origin and colonization trends across the depth gradient in scleractinian corals. Using a phylogenetic approach, we infer the origin and historical trends in directionality and speed of colonization during the diversification in depth. We also examine how the emergence of photo-symbiosis and coloniality, scleractinian corals' most conspicuous phenotypic innovations, have influenced this process. Our results strongly support an offshore-onshore pattern of evolution and varying dispersion capacities along depth associated with trait-defined lineages. These results highlight the relevance of the evolutionary processes occurring at different depths to explain the origin of extant marine biodiversity and the consequences of altering these processes by human impact, highlighting the need to include this overlooked evolutionary history in conservation plans
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Historical warming consistently decreased size, dispersal and speciation rate of fish
There is ongoing debate as to whether fish body size will decrease with global warming and how these changes may impact dispersal ability and speciation rate. Theory predicts that, under warmer temperatures, fish grow to a smaller size, undergo a reduction in dispersal ability and increase speciation rates. However, evaluations of such predictions are hampered owing to the lack of empirical data spanning both wide temporal and geographical scales. Here, using phylogenetic methods, we show that smaller clupeiform fish (anchovies and herrings) occurred historically in warmer waters, moved the shortest distances at low speed and displayed the lowest speciation rates. Furthermore, fish moved faster and evolved rapidly under higher rates of temperature change but these historical rates are far lower than current warming rates. Our results predict a future where smaller clupeiform fish that have reduced ability to move will be more prevalent; this, in turn, may reduce future speciation
Nitrogen Supply Affects Photosynthesis and Photoprotective Attributes During Drought-Induced Senescence in Quinoa
Drought during senescence has become more common in Mediterranean climates in recent years. Chenopodium quinoa Willd has been identified as tolerant to poor soil conditions and drought. Previous observations have found that sufficient nitrogen (N) supply mitigates yield losses under terminal drought conditions. However, there is no understanding of the mechanisms behind this effect. We hypothesized that N up-regulates both photosynthetic and photoprotective elements during drought-induced senescence, alleviating the negative impact of drought on yield. The role of N supply and terminal drought on photoprotection was tested using three Chilean quinoa genotypes from different climatic zones: Faro, UdeC9, and BO78. Plants were grown under high nitrogen (HN) or low nitrogen (LN) conditions and subjected to terminal drought at the onset of senescence. Photosynthetic and photochemical and non-photochemical processes were evaluated at both the onset of drought and after 15 days of drought conditions. N supplementation modified most of the physiological parameters related to photochemical dissipation of energy, photosynthesis, and yield in quinoa. In contrast, water restriction did not affect photosynthesis in quinoa, and its effect on yield was dependent on the genotype. A significant interaction N × G was observed in photosynthesis, relative water content, protein content, Fv/Fm, and chlorophylls. In general, Faro was able to maintain higher levels of these attributes under LN conditions than UdeC9 and BO78. In addition, the interacting effects of N × W regulated the level of most pigments in quinoa as well as the photoprotective induction of non-photochemical quenching (NPQ) during senescence. During terminal drought at LN conditions, Faro presented a larger NPQ induction under drought conditions than UdeC9 and BO78, which was supported by a larger zeaxanthin content and de-epoxidation state of the xanthophyll pool. Interestingly, BO78 did not induce NPQ in response to drought-induced senescence but instead enhanced the content of betacyanins. This response needs to be researched in future works. Finally, we observed that LN supply reduced the correlationship between the de-epoxidation state of the xanthophyll cycle and NPQ. This could be an indication that N supply not only compromised the capacity for photosynthetic performance in quinoa plants, but also affected the plasticity of thermal dissipation, restricting further changes during drought-induced senescence
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Temporal Genetic Variance and Propagule-Driven Genetic Structure Characterize Naturalized Rainbow Trout (Oncorhynchus mykiss) from a Patagonian Lake Impacted by Trout Farming
Knowledge about the genetic underpinnings of invasions—a theme addressed by invasion genetics as a discipline—is still scarce amid well documented ecological impacts of non-native species on ecosystems of Patagonia in South America. One of the most invasive species in Patagonia’s freshwater systems and elsewhere is rainbow trout (Oncorhynchus mykiss). This species was introduced to Chile during the early twentieth century for stocking and promoting recreational fishing; during the late twentieth century was reintroduced for farming purposes and is now naturalized. We used population- and individual-based inference from single nucleotide polymorphisms (SNPs) to illuminate three objectives related to the establishment and naturalization of Rainbow Trout in Lake Llanquihue. This lake has been intensively used for trout farming during the last three decades. Our results emanate from samples collected from five inlet streams over two seasons, winter and spring. First, we found that significant intra- population (temporal) genetic variance was greater than inter-population (spatial) genetic variance, downplaying the importance of spatial divergence during the process of naturalization. Allele frequency differences between cohorts, consistent with variation in fish length between spring and winter collections, might explain temporal genetic differences. Second, individual-based Bayesian clustering suggested that genetic structure within Lake Llanquihue was largely driven by putative farm propagules found at one single stream during spring, but not in winter. This suggests that farm broodstock might migrate upstream to breed during spring at that particular stream. It is unclear whether interbreeding has occurred between “pure” naturalized and farm trout in this and other streams. Third, estimates of the annual number of breeders (N[subscript]b) were below 73 in half of the collections, suggestive of genetically small and recently founded populations that might experience substantial genetic drift. Our results reinforce the notion that naturalized trout originated recently from a small yet genetically diverse source and that farm propagules might have played a significant role in the invasion of Rainbow Trout within a single lake with intensive trout farming. Our results also argue for proficient mitigation measures that include management of escapes and strategies to minimize unintentional releases from farm facilities
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The decoupled nature of basal metabolic rate and body temperature in endotherm evolution
The origins of endothermy in birds and mammals are important events in vertebrate evolution. Endotherms can maintain their body temperature (Tb) over a wide range of ambient temperatures primarily using the heat that is generated continuously by their high basal metabolic rate (BMR)1. There is also an important positive feedback loop as Tb influences BMR1,2,3. Owing to this interplay between BMRs and Tb, many ecologists and evolutionary physiologists posit that the evolution of BMR and Tb must have been coupled during the radiation of endotherms3,4,5, changing with similar trends6,7,8. However, colder historical environments might have imposed strong selective pressures on BMR to compensate for increased rates of heat loss and to keep Tb constant9,10,11,12. Thus, adaptation to cold ambient temperatures through increases in BMR could have decoupled BMR from Tb and caused different evolutionary routes to the modern diversity in these traits. Here we show that BMR and Tb were decoupled in approximately 90% of mammalian phylogenetic branches and 36% of avian phylogenetic branches. Mammalian BMRs evolved with rapid bursts but without a long-term directional trend, whereas Tb evolved mostly at a constant rate and towards colder bodies from a warmer-bodied common ancestor. Avian BMRs evolved predominantly at a constant rate and without a long-term directional trend, whereas Tb evolved with much greater rate heterogeneity and with adaptive evolution towards colder bodies. Furthermore, rapid shifts that lead to both increases and decreases in BMRs were linked to abrupt changes towards colder ambient temperatures—although only in mammals. Our results suggest that natural selection effectively exploited the diversity in mammalian BMRs under diverse, often-adverse historical thermal environments
Assessing Evidence for a Pervasive Alteration in Tropical Tree Communities
In Amazonian tropical forests, recent studies have reported increases in aboveground biomass and in primary productivity, as well as shifts in plant species composition favouring fast-growing species over slow-growing ones. This pervasive alteration of mature tropical forests was attributed to global environmental change, such as an increase in atmospheric CO2 concentration, nutrient deposition, temperature, drought frequency, and/or irradiance. We used standardized, repeated measurements of over 2 million trees in ten large (16–52 ha each) forest plots on three continents to evaluate the generality of these findings across tropical forests. Aboveground biomass increased at seven of our ten plots, significantly so at four plots, and showed a large decrease at a single plot. Carbon accumulation pooled across sites was significant (+0.24 MgC ha−1 y−1, 95% confidence intervals [0.07, 0.39] MgC ha−1 y−1), but lower than reported previously for Amazonia. At three sites for which we had data for multiple census intervals, we found no concerted increase in biomass gain, in conflict with the increased productivity hypothesis. Over all ten plots, the fastest-growing quartile of species gained biomass (+0.33 [0.09, 0.55] % y−1) compared with the tree community as a whole (+0.15 % y−1); however, this significant trend was due to a single plot. Biomass of slow-growing species increased significantly when calculated over all plots (+0.21 [0.02, 0.37] % y−1), and in half of our plots when calculated individually. Our results do not support the hypothesis that fast-growing species are consistently increasing in dominance in tropical tree communities. Instead, they suggest that our plots may be simultaneously recovering from past disturbances and affected by changes in resource availability. More long-term studies are necessary to clarify the contribution of global change to the functioning of tropical forests
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