21,469 research outputs found
Into the Light: Diurnality has Evolved Multiple Times in Geckos
Geckos are the only major lizard group consisting mostly of nocturnal species. Nocturnality is presumed to have evolved early in gecko evolution and geckos possess numerous adaptations to functioning in low light and at low temperatures. However, not all gecko species are nocturnal and most diurnal geckos have their own distinct adaptations to living in warmer, sunlit environments. We reconstructed the evolution of gecko activity patterns using a newly generated time-calibrated phylogeny. Our results provide the first phylogenetic analysis of temporal activity patterns in geckos and confirm an ancient origin of nocturnality at the root of the gecko tree. We identify multiple transitions to diurnality at a variety of evolutionary time scales and transitions back to nocturnality occur in several predominantly diurnal clades. The scenario presented here will be useful in reinterpreting existing hypotheses of how geckos have adapted to varying thermal and light environments. These results can also inform future research of gecko ecology, physiology, morphology and vision as it relates to changes in temporal activity patterns
The Connotative Meaning of the Visual Sign of Tokek (Gekko Gecko) on the T-Shirt Used as a Souvenir in Lombok, West Nusa Tenggara
The background of the study was the use of the visual sign of tokek (Gekko gecko) used in various souvenirs,
one of which was T-shirt, in Lombok. This study aimed at revealing the meaning of the visual sign of tokek (Gekko gecko) on the T-shirt. Purposive sampling technique was used in this study; the sample used was supposed to represent the study, the symmetric and asymmetric types. The connotative meaning of the visual sign of tokek (Gekko gecko) was analyzed using the theory of semiotics in which the Pierce’s theory was employed to see the signs such as icons, indices, and symbols in the picture. The theory proposed by Rolland Barthes was used to analyze the connotative meaning and the reading codes such as narration, hermeneutics, semantics, symbolism, and culture. The results of analyses showed that the sign of visual tokek showed the visual sign of lizards found in the sarcophagus of Aik Renung, Sumbawa, meaning that
the use of the visual sign of tokek referred to the prehistoric situation when the people in Lombok believed
in animism. The use of the sign of visual on the t-shirt used as the souvenir was intended to show the existence and place which differed Lomok Island from the other regions.
Keywords: Connotation meaning, gecko (gekko gecko), and Lombok t-shirt
COLONIZATION OF NORTHERN LOUISIANA BY THE MEDITERRANEAN GECKO, HEMIDACTYLUS TURCICUS
The Mediterranean Gecko, Hemidactylus turcicus, is known to have colonized nearly every state in the southern United States. In Louisiana, the Mediterranean Gecko has been documented in many of the southern parishes, but records for the northern portion of the state are limited. We sampled northern Louisiana parishes to document the presence of the Mediterranean Gecko. We sampled a total of 21 parishes in northern Louisiana and found geckos in 17 of those parishes, 16 of which represent new distribution records for the species. This indicates a significant range expansion of this introduced species throughout northern Louisiana. Geckos were found across a temperature range of 14.0–28.0°C and had a strong association with buildings. The species’ affinity for anthropogenic association and the continual nature of anthropogenic expansion facilitate the high vagility of this species. The result is a successful colonization throughout much of Louisiana and likely continued range expansion throughout the southern United States
Biodiversity in a forest island: reptiles and amphibians of the West African Togo Hills
Our recent surveys of the herpetological diversity of the West African Togo Hills documented a total of 65 reptile and amphibian species, making Kyabobo National Park one of the most diverse sites surveyed in Ghana. We provide accounts for all species recorded along with photographs to aid in identification. We recorded 26 amphibians, including six new records for Kyabobo N. P., one of which is a record for the Togo Hills. Our collection of reptile species (22 lizards, 16 snakes, and one crocodile) also provides new records and range extensions for Kyabobo N. P., such as the first observation of the dwarf crocodile, Osteolaemus tetraspis. Amphibian species still lacking from our surveys in the Togo Hills include several species that are adapted to fast running water or large closed forests, like the Togo toad, Bufo togoensis and the slippery frog, Conraua derooi. Appropriate habitat for such species still remains in Kyabobo, highlighting the need for additional survey work. We draw attention to the importance of conserving forest stream habitats, which will in turn help ensure the persistence of forest-restricted species. We also highlight those species that may prove most useful for evolutionary studies of West African rain forest biogeography
Implementation of RTOS to the WSN node
Bezdrátové senzorické sieťe zväčša používajú `event-driven` operačné systémy. Táto práca diskutuje výhody nevýhody použitia RTOS v bezdrátových senzorických sieťach. Najvhodnejší RTOS je vybratý a sú podniknuté všetky kroky aby bolo možne demonštrovať schopnosť mikrokontrolérov Gecko od EnergyMicro prevádzkovať tento RTOS s nízkou spotrebou energie a demonštrovať jednoduchú bezdrátovú komunikáciu s Atmel AT86RF212 rádiami.Wireless sensors networks mostly use event-driven OSes. This works discusses pros and cons of using RTOS in wirless sensors networks. A most appropriate RTOS is chosen and all necessary steps are undergone to demonstrate EnergyMicro Gecko MCU's ability to run the RTOS with low energy consumption and demonstrate wireless simple communication with Atmel AT86RF212 radios.
Tertiary Climate Change and the Diversification of the Amazonian Gecko Genus Gonatodes (Sphaerodactylidae, Squamata)
The genus Gonatodes is a monophyletic group of small-bodied, diurnal geckos distributed across northern South America, Central America, and the Caribbean. We used fragments of three nuclear genes (RAG2, ACM4, and c-mos) and one mitochondrial gene (16S) to estimate phylogenetic relationships among Amazonian species of Gonatodes. We used Penalized Likelihood to estimate timing of diversification in the genus. Most cladogenesis occurred in the Oligocene and early Miocene and coincided with a burst of diversification in other South American animal groups including mollusks, birds, and mammals. The Oligocene and early Miocene were periods dominated by dramatic climate change and Andean orogeny and we suggest that these factors drove the burst of cladogenesis in Gonatodes geckos as well as other taxa. A common pattern in Amazonian taxa is a biogeographic split between the eastern and western Amazon basin. We observed two clades with this spatial distribution, although large differences in timing of divergence between the east–west taxon pairs indicate that these divergences were not the result of a common vicariant event
Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces
Acknowledgements V.B., N.K.G., and E.A. contributed with conception and experimental design. V.B. performed the experiments. V.B., R.H., A.G., and R.M.M. carried out analysis and interpretation of data. V.B., R.H., A.G., and E.A. wrote the manuscript. V.B. and R.H. contributed equally to this work. V.B. acknowledges funding by SPP 1420 of the German Science Foundation DFG. E.A., N.K.G., and R.H. acknowledge funding from the European Research Council under the European Union/ERC Advanced Grant “Switch2Stick,” Agreement No. 340929.Peer reviewedPublisher PD
Ecology and co-existence of two endemic day gecko (Phelsuma) species in Seychelles native palm forest
In island ecosystems, reptiles play diverse ecological roles as a result of niche broadening, which increases potential niche overlap between species. Ecological niche partitioning is a means of reducing direct competition between coexisting species and differences in habitat use among island gecko species have been suggested as a by-product of specialization to feeding on certain resources. Here, we examine modes and drivers of niche partitioning of two endemic species of Phelsuma gecko (Phelsuma sundbergi and Phelsuma astriata) in relict native palm forest in the Seychelles to further understanding of congeneric reptile co-existence in native habitats. Phelsuma abundance, microhabitat use and habitat composition were quantified in different macrohabitat types. P. sundbergi showed a clear preference for habitat dominated by the coco de mer palm, Lodoicea maldivica and a strong association with male individuals of this dioecious species. P. astriata density increased significantly with arboreal biodiversity but did not display a relationship with a specific tree type. High levels of resource segregation were determined along the microhabitat axis, based on differential tree preference. Our results suggest that P. sundbergi and P. astriata may have evolved to co-exist in this habitat type through partitioning of microhabitat as members of a divergent specialist/generalist assemblage determined by consumption of L. maldivica pollen by P. sundbergi. Our findings concur with the hypothesis that differences in habitat use among island reptiles are a by-product of trophic specialization and support the conservation of native habitat for maintenance of reptile diversity
Coming to America: Multiple Origins of New World Geckos
Geckos in the Western Hemisphere provide an excellent model to study faunal assembly at a continental scale. We generated a time-calibrated phylogeny, including exemplars of all New World gecko genera, to produce a biogeographic scenario for the New World geckos. Patterns of New World gecko origins are consistent with almost every biogeographic scenario utilized by a terrestrial vertebrate with different New World lineages showing evidence of vicariance, dispersal via temporary land bridge, overseas dispersal, or anthropogenic introductions. We also recovered a strong relationship between clade age and species diversity, with older New World lineages having more species than more recently arrived lineages. Our data provide the first phylogenetic hypothesis for all New World geckos and highlight the intricate origins and ongoing organization of continental faunas. The phylogenetic and biogeographical hypotheses presented here provide an historical framework to further pursue research on the diversification and assembly of the New World herpetofauna
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