| 1. |
- 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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| 2. |
- 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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| 3. |
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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
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