| 1. |
- Coates, Melissa
(författare)
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Visual ecology and functional morphology of Cubozoa (Cnidaria)
- 2003
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 43:4, s. 542-548
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Tidskriftsartikel (refereegranskat)abstract
- Jellyfish belong to one of the oldest extant animal phyla, the Cnidaria. The first Cnidaria appear in the fossil record 600 million years ago, preceeding the Cambrian explosion. They are an extremely successful group present in all marine environments and some freshwater environments. In contrast to many animal phyla in which vision is a primary sense Cnidarians do not, generally, employ image forming eyes. One small class stands alone: the Cubozoa. Cubomedusae are commonly known as box jellyfish. They possess image forming eyes (Coates et al., 2001) which certainly evolved independently from other metazoans. Cubomedusae therefore offer a unique perspective on the evolution of image forming eyes. This literature review collects, into one place, what is known about: the multiple eye types of box jellyfish, cubomedusan life history and ecology, and the sensory and neural systems of box jellyfish. Here I discuss how these features set cubomedusae apart from scyphomedusae and hydromedusae. Knowledge in these areas is sparse; the work done to date inspires increased efforts.
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| 2. |
- Jones, Adam G., et al.
(författare)
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The measurement of sexual selection using Bateman's principles : An experimental test in the sex-role-reversed pipefish Syngnathus typhle
- 2005
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 45:5, s. 874-884
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Tidskriftsartikel (refereegranskat)abstract
- Angus J. Bateman's classic study of sexual selection in Drosophila melanogaster has had a major influence on the development of sexual selection theory. In some ways, Bateman's study has served a catalytic role by stimulating debate on sex roles, sexual conflict and other topics in sexual selection. However, there is still considerable disagreement regarding whether or not "Bateman's principles" are helpful in the study of sexual selection. Here, we test the idea that Bateman's principles provide the basis for a useful method to quantify and compare mating systems. In this study, we focus on the sex-role-reversed pipefish Syngnathus typhle as a model system to study the measurement of sexual selection. We set up artificial breeding assemblages of pipefish in the laboratory and used microsatellite markers to resolve parentage. Three different sex-ratio treatments (female-biased, even and male-biased) were used to manipulate the expected intensity of sexual selection. Measures of the mating system based on Bateman's principles were calculated and compared to the expected changes in the intensity of sexual selection. We also compare the results of this study to the results of a similar study of Bateman's principles in the rough-skinned newt, a species with conventional sex roles. The results of this experiment show that measures of the mating system based on Bateman's principles do accurately capture the relative intensities of sexual selection in the different treatments and species. Thus, widespread use of Bateman's principles to quantify mating systems in nature would facilitate comparative studies of sexual selection and mating system evolution.
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| 3. |
- Jönsson, K. Ingemar, 1959-
(författare)
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The evolution of life histories in holo-anhydrobiotic animals : a first approach
- 2005
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Ingår i: Integrative and Comparative Biology. - 1540-7063 .- 1557-7023. ; 45:5, s. 764-770
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Tidskriftsartikel (refereegranskat)abstract
- The life histories of holo-anhydrobiotic animals differ from those of all other organisms by a regular or irregular entrance into an ametabolic state induced by desiccation. Such ametabolic periods will arrest growth and reproduction completely and thus affect primary life history parameters dramatically. The selective forces and the genetic and physiological trade-offs acting on anhydrobiotic animals are to a large extent unknown. Assuming low growth rates and low juvenile to adult survival, general theoretical models on life history responses to stress predict that anhydrobiotic animals will be selected for a high degree of iteroparity, with low fecundity, large egg size, and low total reproductive investment. A high degree of variability in growth and reproduction should create a selective force in the same direction. Although basic empirical data on life history parameters are very scarce, available observations seem to be consistent with this prediction.
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| 4. |
- Kelber, Almut, et al.
(författare)
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Colour vision in diurnal and nocturnal hawkmoths
- 2003
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 43:4, s. 571-579
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Tidskriftsartikel (refereegranskat)abstract
- Diurnal and nocturnal hawkmoths (Sphingidae, Lepidoptera) have three spectral types of receptor sensitive to ultraviolet, blue and green light. As avid flower visitors and pollinators, they use olfactory and visual cues to find and recognise flowers. Moths of the diurnal species Macroglossum stellatarum and the nocturnal species Deilephila elpenor, Hyles lineata and Hyles gallii use and learn the colour of flowers. Nocturnal species can discriminate flowers at starlight intensities when humans and honeybees are colour-blind. M. stellatarum can use achromatic, intensity-related cues if colour cues are absent, and this is probably also true for D. elpenor. Both species can recognise colours even under a changed illumination colour.
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| 5. |
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| 6. |
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| 7. |
- Berio, Fidji, 1992-, et al.
(författare)
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Ontogenetic Plasticity in Shoaling Behavior in a Forage Fish under Warming
- 2023
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Ingår i: Integrative and Comparative Biology. - 1540-7063 .- 1557-7023. ; 63:3, s. 730-741
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Tidskriftsartikel (refereegranskat)abstract
- Shoaling behavior is known to increase survival rates during attacks from predators, minimize foraging time, favor mating, and potentially increase locomotor efficiency. The onset of shoaling typically occurs during the larval phase, but it is unclear how it may improve across ontogenetic stages in forage fishes. Warming is known to increase metabolic rates during locomotion in solitary fish, and shoaling species may adjust their collective behavior to offset the elevated costs of swimming at higher temperatures. In this study, we quantified the effects of warming on shoaling performance across the ontogeny of a small forage fish, zebrafish (Danio rerio) at different speeds. Shoals of larval, juvenile, and adult zebrafish were acclimated at two temperatures (28°C and 32°C), and metabolic rates were quantified prior to and following nonexhaustive exercise at high speed. Shoals of five individuals were filmed in a flow tank to analyze the kinematics of collective movement. We found that zebrafish improve shoaling swimming performance from larvae to juveniles to adults. In particular, shoals become more cohesive, and both tail beat frequency (TBF) and head-to-tail amplitude decrease with ontogeny. Early life stages have higher thermal sensitivity in metabolic rates and TBF especially at high speeds, when compared to adults. Our study shows that shoaling behavior and thermal sensitivity improve as zebrafish shift from larval to juvenile to adult stages.
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| 8. |
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| 9. |
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| 10. |
- Bok, Michael J., et al.
(författare)
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Here, There and Everywhere : The Radiolar Eyes of Fan Worms (Annelida, Sabellidae)
- 2016
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 56:5, s. 784-795
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Tidskriftsartikel (refereegranskat)abstract
- Fan worms (Annelida: Sabellidae) possess some of the strangest eyes in nature. Their eponymous fans are composed of two sets of radiolar tentacles that project from the head up out of the worm's protective tube into the water column. Primarily used for respiration and feeding, these radioles are also often involved in photoreception. They display a surprising diversity of eyes of varying levels of sophistication, ranging from scattered single ocelli to compound eyes with up to hundreds of facets. These photoreceptors could represent a relatively recent evolutionary development to cope with a sessile, tube-dwelling lifestyle, and the primary cerebral eyes (haplessly positioned within the tube most of the time) amount to little more than minute pigment cups with scant visual potential. The radiolar eyes on the other hand, appear to function as visual burglar alarms for detecting looming predators and eliciting a startle response for the worm to rapidly retreat within its fortified tube. Despite sometimes resembling arthropod compound eyes, the radiolar photoreceptors have many canonically vertebrate-like physiological characteristics. Considering the unusual and apparently recently evolved nature of the fan worm radiolar photoreceptors, these animals are an excellent case for examining the emergence of novel visual systems, the development of rudimentary visually guided behaviors, and the function of distributed sensory systems. Here, we review over 100 years of investigations into the anatomical diversity of sabellid radiolar photoreceptors and eyes in an evolutionary and functional context. We provide new information on radiolar eye structure in several species of fan worms, and we attempt to organize the various eye types and ocellar structures into meaningful hierarchies. We discuss the developmental, evolutionary, and functional significance of the radiolar eyes and highlight areas of future interest in deciphering their unique nature.
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| 11. |
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| 12. |
- Bowlin, Melissa, et al.
(författare)
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Grand Challenges in Migration Biology
- 2010
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 50:3, s. 261-279
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Konferensbidrag (refereegranskat)abstract
- Billions of animals migrate each year. To successfully reach their destination, migrants must have evolved an appropriate genetic program and suitable developmental, morphological, physiological, biomechanical, behavioral, and life-history traits. Moreover, they must interact successfully with biotic and abiotic factors in their environment. Migration therefore provides an excellent model system in which to address several of the "grand challenges" in organismal biology. Previous research on migration, however, has often focused on a single aspect of the phenomenon, largely due to methodological, geographical, or financial constraints. Integrative migration biology asks 'big questions' such as how, when, where, and why animals migrate, which can be answered by examining the process from multiple ecological and evolutionary perspectives, incorporating multifaceted knowledge from various other scientific disciplines, and using new technologies and modeling approaches, all within the context of an annual cycle. Adopting an integrative research strategy will provide a better understanding of the interactions between biological levels of organization, of what role migrants play in disease transmission, and of how to conserve migrants and the habitats upon which they depend.
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| 13. |
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| 14. |
- Bowlin, M. S., et al.
(författare)
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The aerodynamic consequences of molt
- 2011
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 51, s. 14-14
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Konferensbidrag (refereegranskat)
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| 15. |
- Colley, Nansi Jo, et al.
(författare)
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Photoreception in Phytoplankton
- 2016
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 56:5, s. 764-775
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Tidskriftsartikel (refereegranskat)abstract
- In many species of phytoplankton, simple photoreceptors monitor ambient lighting. Photoreceptors provide a number of selective advantages including the ability to assess the time of day for circadian rhythms, seasonal changes, and the detection of excessive light intensities and harmful UV light. Photoreceptors also serve as depth gauges in the water column for behaviors such as diurnal vertical migration. Photoreceptors can be organized together with screening pigment into visible eyespots. In a wide variety of motile phytoplankton, including Chlamydomonas, Volvox, Euglena, and Kryptoperidinium, eyespots are light-sensitive organelles residing within the cell. Eyespots are composed of photoreceptor proteins and typically red to orange carotenoid screening pigments. This association of photosensory pigment with screening pigment allows for detection of light directionality, needed for light-guided behaviors such as positive and negative phototaxis. In Chlamydomonas, the eyespot is located in the chloroplast and Chlamydomonas expresses a number of photosensory pigments including the microbial channelrhodopsins (ChR1 and ChR2). Dinoflagellates are unicellular protists that are ecologically important constituents of the phytoplankton. They display a great deal of diversity in morphology, nutritional modes and symbioses, and can be photosynthetic or heterotrophic, feeding on smaller phytoplankton. Dinoflagellates, such as Kryptoperidinium foliaceum, have eyespots that are used for light-mediated tasks including phototaxis. Dinoflagellates belonging to the family Warnowiaceae have a more elaborate eye. Their eye-organelle, called an ocelloid, is a large, elaborate structure consisting of a focusing lens, highly ordered retinal membranes, and a shield of dark pigment. This complex eye-organelle is similar to multicellular camera eyes, such as our own. Unraveling the molecular makeup, structure and function of dinoflagellate eyes, as well as light-guided behaviors in phytoplankton can inform us about the selective forces that drove evolution in the important steps from light detection to vision. We show here that the evolution from simple photoreception to vision seems to have independently followed identical paths and principles in phytoplankton and animals, significantly strengthening our understanding of this important biological process.
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| 16. |
- Cronin, Thomas W, et al.
(författare)
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Crustacean Larvae-Vision in the Plankton
- 2017
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 57:5, s. 1139-1150
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Forskningsöversikt (refereegranskat)abstract
- We review the visual systems of crustacean larvae, concentrating on the compound eyes of decapod and stomatopod larvae as well as the functional and behavioral aspects of their vision. Larval compound eyes of these macrurans are all built on fundamentally the same optical plan, the transparent apposition eye, which is eminently suitable for modification into the abundantly diverse optical systems of the adults. Many of these eyes contain a layer of reflective structures overlying the retina that produces a counterilluminating eyeshine, so they are unique in being camouflaged both by their transparency and by their reflection of light spectrally similar to background light to conceal the opaque retina. Besides the pair of compound eyes, at least some crustacean larvae have a non-imaging photoreceptor system based on a naupliar eye and possibly other frontal eyes. Larval compound-eye photoreceptors send axons to a large and well-developed optic lobe consisting of a series of neuropils that are similar to those of adult crustaceans and insects, implying sophisticated analysis of visual stimuli. The visual system fosters a number of advanced and flexible behaviors that permit crustacean larvae to survive extended periods in the plankton and allows them to reach acceptable adult habitats, within which to metamorphose.
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| 17. |
- Dawson, H. M., et al.
(författare)
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Large Diversity in Nitrogen- and Sulfur-Containing Compatible Solute Profiles in Polar and Temperate Diatoms
- 2020
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Ingår i: Integrative and Comparative Biology. - : OXFORD UNIV PRESS INC. - 1540-7063 .- 1557-7023. ; 60:6, s. 1401-1413
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Tidskriftsartikel (refereegranskat)abstract
- Intense bottom-ice algal blooms, often dominated by diatoms, are an important source of food for grazers, organic matter for export during sea ice melt, and dissolved organic carbon. Sea-ice diatoms have a number of adaptations, including accumulation of compatible solutes, that allows them to inhabit this highly variable environment characterized by extremes in temperature, salinity, and light. In addition to protecting them from extreme conditions, these compounds present a labile, nutrient-rich source of organic matter, and include precursors to climate active compounds (e.g., dimethyl sulfide [DMS]), which are likely regulated with environmental change. Here, intracellular concentrations of 45 metabolites were quantified in three sea-ice diatom species and were compared to two temperate diatom species, with a focus on compatible solutes and free amino acid pools. There was a large diversity of metabolite concentrations between diatoms with no clear pattern identifiable for sea-ice species. Concentrations of some compatible solutes (isethionic acid, homarine) approached 1 M in the sea-ice diatoms, Fragilariopsis cylindrus and Navicula cf. perminuta, but not in the larger sea-ice diatom, Nitzschia lecointei or in the temperate diatom species. The differential use of compatible solutes in sea-ice diatoms suggests different adaptive strategies and highlights which small organic compounds may be important in polar biogeochemical cycles.
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| 18. |
- Day, L. B., et al.
(författare)
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Correlated Evolution of Acrobatic Display and Both Neural and Somatic Phenotypic Traits in Manakins (Pipridae)
- 2021
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 61:4, s. 1343-1362
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Tidskriftsartikel (refereegranskat)abstract
- Brightly colored manakin (Ayes: Pipridae) males are known for performing acrobatic displays punctuated by non-vocal sounds (sonations) in order to attract dull colored females. The complexity of the display sequence and assortment of display elements involved (e.g., sonations, acrobatic maneuvers, and cooperative performances) varies considerably across manakin species. Species-specific display elements coevolve with display-distinct specializations of the neuroanatomical, muscular, endocrine, cardiovascular, and skeletal systems in the handful of species studied. Conducting a broader comparative study, we previously found positive associations between display complexity and both brain mass and body mass across eight manakin genera, indicating selection for neural and somatic expansion to accommodate display elaboration. Whether this gross morphological variation is due to overall brain and body mass expansion (concerted evolution) versus size increases in only functionally relevant brain regions and growth of particular body ("somatic") features (mosaic evolution) remains to be explored. Here, we test the hypothesis that cross-species variation in male brain mass and body mass is driven by mosaic evolution. We predicted positive associations between display complexity and variation in the volume of the cerebellum and sensorimotor arcopallium, brain regions which have roles in sensorimotor processes, and learning and performance of precisely timed and sequenced thoughts and movements, respectively. In contrast, we predicted no associations between the volume of a limbic arcopallial nucleus or a visual thalamic nudeus and display complexity as these regions have no-specific functional relationship to display behavior. For somatic features, we predicted that the relationship between body mass and complexity would not include contributions of tarsus length based on a recent study suggesting selection on tarsus length is less labile than body mass. We tested our hypotheses in males from 12 manakin species and a closely related flycatcher. Our analyses support mosaic evolution of neural and somatic features functionally relevant to display and indicate that sexual selection for acrobatic complexity increases the capacity for procedural learning via cerebellar enlargement and may decrease maneuverability via increases in tarsus length.
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| 19. |
- Di Santo, Valentina
(författare)
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EcoPhysioMechanics : Integrating Energetics and Biomechanics to Understand Fish Locomotion under Climate Change
- 2022
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 62:3, s. 711-720
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Tidskriftsartikel (refereegranskat)abstract
- Ecological physiologists and biomechanists have investigated swimming performance in a diversity of fishes; however, the connection between form, function, and energetics of locomotion has been rarely evaluated in the same system and under climate change scenarios. In this perspective, I argue that working within the framework of “EcoPhysioMechanics,” i.e. integrating energetics and biomechanics tools, to measure locomotor performance and behavior under different abiotic factors, improves our understanding of the mechanisms, limits and costs of movement. To demonstrate how EcoPhysioMechanics can be applied to locomotor studies, I outline how linking biomechanics and physiology allows us to understand how fishes may modulate their movement to achieve high speeds or reduce the costs of locomotion. I also discuss how the framework is necessary to quantify swimming capacity under climate change scenarios. Finally, I discuss current dearth of integrative studies and gaps in empirical datasets that are necessary to understand fish swimming under changing environments.
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| 20. |
- Engel, Sophia, et al.
(författare)
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The Role of Wind-Tunnel Studies in Integrative Research on Migration Biology
- 2010
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 50:3, s. 323-335
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Konferensbidrag (refereegranskat)abstract
- Wind tunnels allow researchers to investigate animals' flight under controlled conditions, and provide easy access to the animals during flight. These increasingly popular devices can benefit integrative migration biology by allowing us to explore the links between aerodynamic theory and migration as well as the links between flight behavior and physiology. Currently, wind tunnels are being used to investigate many different migratory phenomena, including the relationship between metabolic power and flight speed and carry-over effects between different seasons. Although biotelemetry is also becoming increasingly common, it is unlikely that it will be able to completely supplant wind tunnels because of the difficulty of measuring or varying parameters such as flight speed or temperature in the wild. Wind tunnels and swim tunnels will therefore continue to be important tools we can use for studying integrative migration biology.
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| 21. |
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| 22. |
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| 23. |
- Hart, M. W., et al.
(författare)
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Selection on coevolving human gamete recognition genes
- 2016
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Ingår i: Integrative and Comparative Biology. - Simon Fraser Univ, Burnaby, BC V5A 1S6, Canada. Arizona State Univ, Tempe, AZ 85287 USA. Univ Chicago, Chicago, IL 60637 USA. Uppsala Univ, Uppsala, Sweden.. - 1540-7063 .- 1557-7023. ; 56, s. E84-E84
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 24. |
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| 25. |
- Henze, Miriam, et al.
(författare)
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The Dynamic Evolutionary History of Pancrustacean Eyes and Opsins.
- 2015
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 55:5, s. 830-842
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Tidskriftsartikel (refereegranskat)abstract
- Pancrustacea (Hexapoda plus Crustacea) display an enormous diversity of eye designs, including multiple types of compound eyes and single-chambered eyes, often with color vision and/or polarization vision. Although the eyes of some pancrustaceans are well-studied, there is still much to learn about the evolutionary paths to this amazing visual diversity. Here, we examine the evolutionary history of eyes and opsins across the principle groups of Pancrustacea. First, we review the distribution of lateral and median eyes, which are found in all major pancrustacean clades (Oligostraca, Multicrustacea, and Allotriocarida). At the same time, each of those three clades has taxa that lack lateral and/or median eyes. We then compile data on the expression of visual r-opsins (rhabdomeric opsins) in lateral and median eyes across Pancrustacea and find no evidence for ancient opsin clades expressed in only one type of eye. Instead, opsin clades with eye-specific expression are products of recent gene duplications, indicating a dynamic past, during which opsins often changed expression from one type of eye to another. We also investigate the evolutionary history of peropsins and r-opsins, which are both known to be expressed in eyes of arthropods. By searching published transcriptomes, we discover for the first time crustacean peropsins and suggest that previously reported odonate opsins may also be peropsins. Finally, from analyzing a reconciled, phylogenetic tree of arthropod r-opsins, we infer that the ancestral pancrustacean had four visual opsin genes, which we call LW2, MW1, MW2, and SW. These are the progenitors of opsin clades that later were variously duplicated or lost during pancrustacean evolution. Together, our results reveal a particularly dynamic history, with losses of eyes, duplication and loss of opsin genes, and changes in opsin expression between types of eyes.
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| 26. |
- Hill, G. E., et al.
(författare)
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Genetic Basis for Red Coloration in Birds
- 2017
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Ingår i: Integrative and Comparative Biology. - : OXFORD UNIV PRESS INC. - 1540-7063 .- 1557-7023. ; 57, s. E292-E292
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 27. |
- Hoogewijs, D., et al.
(författare)
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From critters to cancers: bridging comparative and clinical research on oxygen sensing, HIF signaling, and adaptations towards hypoxia
- 2007
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 47:4, s. 552-577
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this symposium at the First International Congress of Respiratory Biology (ICRB) was to enhance communication between comparative biologists and cancer researchers working on O-2 sensing via the HIF pathway. Representatives from both camps came together on August 13-16, 2006, in Bonn, Germany, to discuss molecular adaptations that occur after cells have been challenged by a reduced (hypoxia) or completely absent (anoxia) supply of oxygen. This brief "critters-to-cancer" survey discusses current projects and new directions aimed at improving understanding of hypoxic signaling and developing therapeutic interventions.
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| 28. |
- Husby, Arild, Associate Senior Lecturer
(författare)
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On the Use of Blood Samples for Measuring DNA Methylation in Ecological Epigenetic Studies
- 2020
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Ingår i: Integrative and Comparative Biology. - : OXFORD UNIV PRESS INC. - 1540-7063 .- 1557-7023. ; 60:6, s. 1558-1566
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Tidskriftsartikel (refereegranskat)abstract
- There is increasing interest in understanding the potential for epigenetic factors to contribute to phenotypic diversity in evolutionary biology. One well studied epigenetic mechanism is DNA methylation, the addition of a methyl group to cytosines, which have the potential to alter gene expression depending on the genomic region in which it takes place. Obtaining information about DNA methylation at genome-wide scale has become straightforward with the use of bisulfite treatment in combination with reduced representation or whole-genome sequencing. While it is well recognized that methylation is tissue specific, a frequent limitation for many studies is that sampling-specific tissues may require sacrificing individuals, something which is generally undesirable and sometimes impossible. Instead, information about DNA methylation patterns in the blood is frequently used as a proxy tissue. This can obviously be problematic if methylation patterns in the blood do not reflect that in the relevant tissue. Understanding how, or if, DNA methylation in blood reflect DNA methylation patterns in other tissues is therefore of utmost importance if we are to make inferences about how observed differences in methylation or temporal changes in methylation can contribute to phenotypic variation. The aim of this review is to examine what we know about the potential for using blood samples in ecological epigenetic studies. I briefly outline some methods by which we can measure DNA methylation before I examine studies that have compared DNA methylation patterns across different tissues and, finally, examine how useful blood samples may be for ecological studies of DNA methylation. Ecological epigenetic studies are in their infancy, but it is paramount for the field to move forward to have detailed information about tissue and time dependence relationships in methylation to gain insights into if blood DNA methylation patterns can be a reliable bioindicator for changes in methylation that generate phenotypic variation in ecologically important traits.
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| 29. |
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| 30. |
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| 31. |
- Leslie, CE, et al.
(författare)
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Estrogenic Modulation of Retinal Sensitivity in Reproductive Female Túngara Frogs
- 2021
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Ingår i: Integrative and comparative biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 61:1, s. 231-239
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Tidskriftsartikel (refereegranskat)abstract
- Although mate searching behavior in female túngara frogs (Physalaemus pustulosus) is nocturnal and largely mediated by acoustic cues, male signaling includes visual cues produced by the vocal sac. To compensate for these low light conditions, visual sensitivity in females is modulated when they are in a reproductive state, as retinal thresholds are decreased. This study tested whether estradiol (E2) plays a role in this modulation. Female túngara frogs were injected with either human chorionic gonadotropin (hCG) or a combination of hCG and fadrozole. hCG induces a reproductive state and increases retinal sensitivity, while fadrozole is an aromatase inhibitor that blocks hCG-induced E2 synthesis. In an analysis of scotopic electroretinograms (ERGs), hCG treatment lowered the threshold for eliciting a b-wave response, whereas the addition of fadrozole abolished this effect, matching thresholds in non-reproductive saline-injected controls. This suggests that blocking E2 synthesis blocked the hCG-mediated reproductive modulation of retinal sensitivity. By implicating E2 in control of retinal sensitivity, our data add to growing evidence that the targets of gonadal steroid feedback loops include sensory receptor organs, where stimulus sensitivity may be modulated, rather than more central brain nuclei, where modulation may affect mechanisms involved in motivation.
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| 32. |
- Marras, Stefano, et al.
(författare)
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Not So Fast : Swimming Behavior of Sailfish during Predator-Prey Interactions using High-Speed Video and Accelerometry
- 2015
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 55:4, s. 719-727
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Tidskriftsartikel (refereegranskat)abstract
- Synopsis Billfishes are considered among the fastest swimmers in the oceans. Despite early estimates of extremely high speeds, more recent work showed that these predators (e.g., blue marlin) spend most of their time swimming slowly, rarely exceeding 2 m s(-1). Predator-prey interactions provide a context within which one may expect maximal speeds both by predators and prey. Beyond speed, however, an important component determining the outcome of predator-prey encounters is unsteady swimming (i.e., turning and accelerating). Although large predators are faster than their small prey, the latter show higher performance in unsteady swimming. To contrast the evading behaviors of their highly maneuverable prey, sailfish and other large aquatic predators possess morphological adaptations, such as elongated bills, which can be moved more rapidly than the whole body itself, facilitating capture of the prey. Therefore, it is an open question whether such supposedly very fast swimmers do use high-speed bursts when feeding on evasive prey, in addition to using their bill for slashing prey. Here, we measured the swimming behavior of sailfish by using high-frequency accelerometry and high-speed video observations during predator-prey interactions. These measurements allowed analyses of tail beat frequencies to estimate swimming speeds. Our results suggest that sailfish burst at speeds of about 7 m s(-1) and do not exceed swimming speeds of 10 m s(-1) during predator-prey interactions. These speeds are much lower than previous estimates. In addition, the oscillations of the bill during swimming with, and without, extension of the dorsal fin (i.e., the sail) were measured. We suggest that extension of the dorsal fin may allow sailfish to improve the control of the bill and minimize its yaw, hence preventing disturbance of the prey. Therefore, sailfish, like other large predators, may rely mainly on accuracy of movement and the use of the extensions of their bodies, rather than resorting to top speeds when hunting evasive prey.
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| 33. |
- Natesan, D., et al.
(författare)
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Airflow mediated antennal positioning in flying hawkmoths
- 2016
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Ingår i: Integrative and Comparative Biology. - Natl Ctr Biol Sci, Bangalore, Karnataka, India. KTH, Stockholm, Sweden.. - 1540-7063 .- 1557-7023. ; 56, s. E159-E159
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 34. |
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| 35. |
- Nilsson, Dan E., et al.
(författare)
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Low-Resolution Vision-at the Hub of Eye Evolution
- 2017
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 57:5, s. 1066-1070
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Tidskriftsartikel (refereegranskat)abstract
- Simple roles for photoreception are likely to have preceded more demanding ones such as vision. The driving force behind this evolution is the improvement and elaboration of animal behaviors using photoreceptor input. Because the basic role for all senses aimed at the external world is to guide behavior, we argue here that understanding this "behavioral drive" is essential for unraveling the evolutionary past of the senses. Photoreception serves many different types of behavior, from simple shadow responses to visual communication. Based on minimum performance requirements for different types of tasks, photoreceptors have been argued to have evolved from non-directional receptors, via directional receptors, to low-resolution vision, and finally to high-resolution vision. Through this sequence, the performance requirements on the photoreceptors have gradually changed from broad to narrow angular sensitivity, from slow to fast response, and from low to high contrast sensitivity during the evolution from simple to more advanced and demanding behaviors. New behaviors would only evolve if their sensory performance requirements to some degree overlap with the requirements of already existing behaviors. This need for sensory "performance continuity" must have determined the order by which behaviors have evolved and thus been an important factor guiding animal evolution. Naturally, new behaviors are most likely to evolve from already existing behaviors with similar neural processing needs and similar motor responses, pointing to "neural continuity" as another guiding factor in sensory evolution. Here we use these principles to derive an evolutionary tree for behaviors driven by photoreceptor input.
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| 36. |
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| 37. |
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| 38. |
- Ortega-Hernandez, J., et al.
(författare)
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Origin and Evolution of the Panarthropod Head - a Deep Time Perspective
- 2017
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Ingår i: Integrative and Comparative Biology. - Univ Cambridge, Cambridge, England. Uppsala Univ, Uppsala, Sweden. : OXFORD UNIV PRESS INC. - 1540-7063 .- 1557-7023. ; 57, s. E369-E369
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 39. |
- Ouyang, Jenny Q., et al.
(författare)
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A New Framework for Urban Ecology : An Integration of Proximate and Ultimate Responses to Anthropogenic Change
- 2018
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 58:5, s. 915-928
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Tidskriftsartikel (refereegranskat)abstract
- As urban areas continue to grow, understanding how species respond and adapt to urban habitats is becoming increasingly important. Knowledge of the mechanisms behind observed phenotypic changes of urban-dwelling animals will enable us to better evaluate the impact of urbanization on current and future generations of wildlife and predict how animals respond to novel environments. Recently, urban ecology has emerged not only as a means of understanding organismal adaptation but also as a framework for exploring mechanisms mediating evolutionary phenomena. Here, we have identified four important research topics that will advance the field of urban ecology and shed light on the proximate and ultimate causes of the phenotypic differences commonly seen among species and populations that vary in their responses to urbanization. First, we address the ecological and socio-economic factors that characterize cities, how they might interact with each other, and how they affect urban species. Second, we ask which are the proximate mechanisms underlying the emergence over time of novel traits in urban organisms, focusing on developmental effects. Third, we emphasize the importance of understanding the ultimate causations that link phenotypic shifts to function. This question highlights the need to quantify the strength and direction of selection that urban individuals are exposed to, and whether the phenotypic shifts associated with life in the city are adaptive. Lastly, we stress the need to translate how individual-level responses scale up to population dynamics. Understanding the mechanistic underpinnings of variation among populations and species in their responses to urbanization will unravel species resilience to environmental perturbation, which will facilitate predictive models for sustainability and development of green cities that maintain or even increase urban biodiversity and wildlife health and wellbeing.
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| 40. |
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| 41. |
- Redmond, N. E., et al.
(författare)
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Phylogeny and Systematics of Demospongiae in Light of New Small-Subunit Ribosomal DNA (18S) Sequences
- 2013
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 53:3, s. 388-415
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Tidskriftsartikel (refereegranskat)abstract
- The most diverse and species-rich class of the phylum Porifera is Demospongiae. In recent years, the systematics of this clade, which contains more than 7000 species, has developed rapidly in light of new studies combining molecular and morphological observations. We add more than 500 new, nearly complete 18S sequences (an increase of more than 200%) in an attempt to further enhance understanding of the phylogeny of Demospongiae. Our study specifically targets representation of type species and genera that have never been sampled for any molecular data in an effort to accelerate progress in classifying this diverse lineage. Our analyses recover four highly supported subclasses of Demospongiae: Keratosa, Myxospongiae, Haploscleromorpha, and Heteroscleromorpha. Within Keratosa, neither Dendroceratida, nor its two families, Darwinellidae and Dictyodendrillidae, are monophyletic and Dictyoceratida is divided into two lineages, one predominantly composed of Dysideidae and the second containing the remaining families (Irciniidae, Spongiidae, Thorectidae, and Verticillitidae). Within Myxospongiae, we find Chondrosida to be paraphyletic with respect to the Verongida. We amend the latter to include species of the genus Chondrosia and erect a new order Chondrillida to contain remaining taxa from Chondrosida, which we now discard. Even with increased taxon sampling of Haploscleromorpha, our analyses are consistent with previous studies; however, Haliclona species are interspersed in even more clades. Haploscleromorpha contains five highly supported clades, each more diverse than previously recognized, and current families are mostly polyphyletic. In addition, we reassign Janulum spinispiculum to Haploscleromorpha and resurrect Reniera filholi as Janulum filholi comb. nov. Within the large clade Heteroscleromorpha, we confirmed 12 recently identified clades based on alternative data, as well as a sister-group relationship between the freshwater Spongillida and the family Vetulinidae. We transfer Stylissa flabelliformis to the genus Scopalina within the family Scopalinidae, which is of uncertain position. Our analyses uncover a large, strongly supported clade containing all heteroscleromorphs other than Spongillida, Vetulinidae, and Scopalinidae. Within this clade, there is a major division separating Axinellidae, Biemnida, Tetractinellida, Bubaridae, Stelligeridae, Raspailiidae, and some species of Petromica, Topsentia, and Axinyssa from Agelasida, Polymastiidae, Placospongiidae, Clionaidae, Spirastrellidae, Tethyidae, Poecilosclerida, Halichondriidae, Suberitidae, and Trachycladus. Among numerous results: (1) Spirophorina and its family Tetillidae are paraphyletic with respect to a strongly supported Astrophorina within Tetractinellida; (2) Agelasida is the earliest diverging lineage within the second clade listed above; and (3) Merlia and Desmacella appear to be the earliest diverging lineages of Poecilosclerida.
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| 42. |
- Salmon, Pablo, et al.
(författare)
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Effects of the Urban Environment on Oxidative Stress in Early Life : Insights from a Cross-fostering Experiment
- 2018
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; , s. 986-994
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Tidskriftsartikel (refereegranskat)abstract
- As urban areas expand rapidly worldwide, wildlife is exposed to a wide range of novel environmental stressors, such as increased air pollution and artificial light at night. Birds in highly polluted and/or urbanized habitats have been found to have increased antioxidant protection, which is likely important to avoid accumulation of oxidative damage, which can have negative fitness consequences. Yet, the current knowledge about the ontogeny of antioxidant protection in urban areas is limited; i.e., is the capacity to up-regulate the antioxidant defences already established during pre-natal development, or does it manifest itself during post-natal development? We cross-fostered great tit (Parus major) nestlings within and between urban and rural habitats, to determine if oxidative stress (measured as non-enzymatic total antioxidant capacity, superoxide dismutase (SOD), and plasma lipid peroxidation) is affected by habitat of origin and/or by habitat of rearing. The results demonstrate that being reared in the urban environment triggers an increase in SOD (an intracellular, enzymatic antioxidant) independent of natal habitat. Oxidative damage increased with hatching date in urban-reared nestlings, but there was little seasonal change in rural-reared nestlings. Total antioxidant capacity was neither affected by habitat of rearing or habitat of origin, but we observed a decline with hatching date in both rearing habitats. Taken together, our results support the growing evidence that the urban environment induces a direct plastic adjustment in antioxidant protection, but that up-regulation is not sufficient to avoid increased oxidative damage in late-hatched broods. Future studies should explore the underlying causes for this effect in late-hatched broods and whether it has any negative long-term implications, both at the individual- and the population level.
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| 43. |
- Sanders, Kate L., et al.
(författare)
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Independent innovation in the evolution of paddle-shaped tails in viviparous sea snakes (Elapidae Hydrophiinae)
- 2012
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Ingår i: Integrative and Comparative Biology. - 1540-7063 .- 1557-7023. ; 52:2, s. 311-320
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Tidskriftsartikel (refereegranskat)abstract
- The viviparous sea snakes (Hydrophiinae) comprise ∼90% of living marine reptiles and display many physical and behavioral adaptations for breathing, diving, and achieving osmotic balance in marine habitats. Among the most important innovations found in marine snakes are their paddle-shaped (dorsoventrally expanded) tails, which provide propulsive thrust in the dense aquatic medium. Here, we reconstruct the evolution of caudal paddles in viviparous sea snakes using a dated molecular phylogeny for all major lineages and computed tomography of internal osteological structures. Bayesian ancestral state reconstructions show that extremely large caudal paddles supported by elongated vertebral processes are unlikely to have been present in the most recent common ancestor of extant sea snakes. Instead, these characters appear to have been acquired independently in two highly marine lineages of relatively recent origin. Both the Aipysurus and Hydrophis lineages have elongated neural spines that support the dorsal edge of their large paddles. However, whereas in the Aipysurus lineage the ventral edge of the paddle is supported by elongated haemapophyses, this support is provided by elongated and ventrally directed pleurapophyses in the Hydrophis lineage. Three semi-marine lineages (Hydrelaps, Ephalophis, and Parahydrophis) form the sister group to the Hydrophis clade and have small paddles with poorly developed dorsal and ventral supports, consistent with their amphibious lifestyle. Overall, our results suggest that not only are the viviparous hydrophiines the only lineage of marine snakes to have acquired extremely large, skeletally supported caudal paddles but also that this innovation has occurred twice in the group in the past ∼2–6 million years.
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| 44. |
- Sanders, Kate L., et al.
(författare)
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Independent innovation in the evolution of paddle-shaped tails in viviparous sea snakes (Elapidae Hydrophiinae)
- 2012
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press. - 1540-7063 .- 1557-7023. ; 52:2, s. 311-320
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Tidskriftsartikel (refereegranskat)abstract
- The viviparous sea snakes (Hydrophiinae) comprise ∼90% of living marine reptiles and display many physical and behavioral adaptations for breathing, diving, and achieving osmotic balance in marine habitats. Among the most important innovations found in marine snakes are their paddle-shaped (dorsoventrally expanded) tails, which provide propulsive thrust in the dense aquatic medium. Here, we reconstruct the evolution of caudal paddles in viviparous sea snakes using a dated molecular phylogeny for all major lineages and computed tomography of internal osteological structures. Bayesian ancestral state reconstructions show that extremely large caudal paddles supported by elongated vertebral processes are unlikely to have been present in the most recent common ancestor of extant sea snakes. Instead, these characters appear to have been acquired independently in two highly marine lineages of relatively recent origin. Both the Aipysurus and Hydrophis lineages have elongated neural spines that support the dorsal edgeof their large paddles. However, whereas in the Aipysurus lineage the ventral edge of the paddle is supported by elongated haemapophyses, this support is provided by elongated and ventrally directed pleurapophyses in the Hydrophis lineage. Three semi-marine lineages (Hydrelaps, Ephalophis, and Parahydrophis) form the sister group to the Hydrophis clade and have small paddles with poorly developed dorsal and ventral supports, consistent with their amphibious lifestyle. Overall, our results suggest that not only are the viviparous hydrophiines the only lineage of marine snakes to have acquired extremely large, skeletally supported caudal paddles but also that this innovation has occurred twice in the group in the past ∼2–6 million years.
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| 45. |
- Stöckl, Anna, et al.
(författare)
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Resolving the trade-off between visual sensitivity and spatial acuity - lessons from hawkmoths
- 2017
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1557-7023 .- 1540-7063. ; 57:5, s. 1093-1103
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Tidskriftsartikel (refereegranskat)abstract
- The visual systems of many animals, particularly those active during the day, are optimized for high spatial acuity. However, at night, when photons are sparse and the visual signal competes with increased noise levels, fine spatial resolution cannot be sustained and is traded-off for the greater sensitivity required to see in dim light. High spatial acuity demands detectors and successive visual processing units whose receptive fields each cover only a small area of visual space, in order to reassemble a finely sampled and well resolved image. However, the smaller the sampled area, the fewer the photons that can be collected, and thus the worse the visual sensitivity becomes—leading to the classical trade-off between sensitivity and resolution. Nocturnal animals usually resolve this trade-off in favour of sensitivity, and thus have lower spatial acuity than their diurnal counterparts. Here we review results highlighting how hawkmoths, a highly visual group of insects with species active at different light intensities, resolve the trade-off between sensitivity and spatial resolution. We compare adaptations both in the optics and retina, as well as at higher levels of neural processing in a nocturnal and a diurnal hawkmoth species, and also give a perspective on the behavioral consequences. We broaden the scope of our review by drawing comparisons with the adaptive strategies used by other nocturnal and diurnal insects.
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| 46. |
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| 47. |
- Treberg, Jason R., et al.
(författare)
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Comparing Electron Leak in Vertebrate Muscle Mitochondria
- 2018
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Ingår i: Integrative and Comparative Biology. - : Oxford University Press (OUP). - 1540-7063 .- 1557-7023. ; 58:3, s. 495-505
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial electron transfer for oxidative ATP regeneration is linked to reactive oxygen species (ROS) production in aerobic eukaryotic cells. Because they can contribute to signaling as well as oxidative damage in cells, these ROS have profound impact for the physiology and survival of the organism. Although mitochondria have been recognized as a potential source for ROS for about 50 years, the mechanistic understanding on molecular sites and processes has advanced recently. Most experimental approaches neglect thermal variability among species although temperature impacts mitochondrial processes significantly. Here we delineate the importance of temperature by comparing muscle mitochondrial ROS formation across species. Measuring the thermal sensitivity of respiration, electron leak rate (ROS formation), and the antioxidant capacity (measured as H2O2 consumption) in intact mitochondria of representative ectothermic and endothermic vertebrate species, our results suggest that using a common assay temperature is inappropriate for comparisons of organisms with differing body temperatures. Moreover, we propose that measuring electron leak relative to the mitochondrial antioxidant capacity (the oxidant ratio) may be superior to normalizing relative to respiration rates or mitochondrial protein for comparisons of mitochondrial metabolism of ROS across species of varying mitochondrial respiratory capacities.
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| 48. |
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| 49. |
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| 50. |
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