The process of species diversification is often associated with niche shifts in the newly arising lineages so that interspecific competition is minimized. However, an opposing force known as niche conservatism causes that related species tend to resemble each other in their niche requirements. Due to the inherent multidimensionality of niche space, some niche components may be subject to divergent evolution while others remain conserved in the process of speciation. One such possible component is the species' climatic niche. Here, we test the role of climatic niche evolution on the diversification of the Old World cat snakes of the genus Telescopus. These slender, nocturnal snakes are distributed in arid and semiarid areas throughout Africa, southwest Asia and adjoining parts of Europe. Because phylogenetic relationships among the Telescopus species are virtually unknown, we generated sequence data for eight genetic markers from ten of the 14 described species and reconstructed a time-calibrated phylogeny of the genus. Phylogenetic analysesindicate that the genus is of considerably old origin that dates back to the Eocene/Oligocene boundary. Biogeographical analyses place the ancestor of the genus in Africa, where it diversified into the species observed today and from where it colonized Arabia and the Levant twice independently. The colonization of Arabia occurred in the Miocene, that of the Levant either in the Late Oligocene or Early Miocene. We then identified temperature and precipitation niche space and breadth of the species included in the phylogeny and examined whether there is phylogenetic signal in these climatic niche characteristics. Despite the vast range of the genus and its complex biogeographic history, most Telescopus species have similar environmental requirements with preference for arid to semiarid conditions. One may thus expect that the genus' climatic niche will be conserved. However, our results suggest that most of the climatic niche axes examined show no phylogenetic signal, being indicative of no evolutionary constraints on the climatic niche position and niche breadth in Telescopus. The only two variables with positive phylogenetic signal (temperature niche position and precipitation niche breadth) evolved under the Brownian motion model, also indicating no directional selection on these traits. As a result, climatic niche evolution does not seem to be the major driver for the diversification in Telescopus.

• MeSH
• analýza hlavních komponent MeSH
• Bayesova věta MeSH
• biologická evoluce * MeSH
• časové faktory MeSH
• Colubridae klasifikace   MeSH
• déšť MeSH
• fylogeneze MeSH
• fylogeografie * MeSH
• kalibrace MeSH
• podnebí * MeSH
• teplota MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Afrika MeSH
• Arábie MeSH

The genus Rhynchocalamus comprises three species distributed in Southwest Asia. Little is known about them, most probably because of their secretive fossorial lifestyle. The poor knowledge of the genus is even underscored by the fact that its phylogenetic affinities remained unclear until very recently. The least known of the species, Rhynchocalamus arabicus, is known only from the holotype collected in Aden, Yemen, and it has not been observed since its description in 1933. Here we provide a second record for this species, which represents the first record of this genus for Oman. This extends its range in southern Arabia by more than 1000 km. The observed specimen was determined as R. arabicus on the basis of its similarity in size, color, and scalation with the holotype. Furthermore, we sequenced three mitochondrial (12S, 16S, cytb) and one nuclear (cmos) genes for R. arabicus and for two individuals of R. melanocephalus and one R. satunini and inferred the phylogenetic relationships of all currently recognized species of the genus for the first time. The results of our phylogenetic analyses indicate that Rhynchocalamus is a member of the Western Palearctic clade of Colubrinae and is sister to Lytorhynchus, with which it forms a very well supported clade and shares some morphological characters. As our results show, R. satunini is the basal lineage of the genus and R. melanocephalus is sister to R. arabicus.

• MeSH
• anatomické struktury zvířat anatomie a histologie   růst a vývoj   MeSH
• Colubridae anatomie a histologie   klasifikace   genetika   růst a vývoj   MeSH
• fylogeneze * MeSH
• RNA ribozomální 16S genetika   MeSH
• rozšíření zvířat MeSH
• velikost orgánu MeSH
• velikost těla MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Omán MeSH

Understanding how species responded to past climate change can provide information about how they may respond to the current global warming. Here we show how a European reptile species responded to the last natural global warming event at the Pleistocene-Holocene transition that led to the Holocene climatic optimum approximately 5000-8000 years ago. The Aesculapian snake, Zamenis longissimus, is a thermophilous species whose present-day distribution in the southern half of Europe is a remnant of much wider range during the Holocene climatic optimum when populations occurred as far north as Denmark. These northern populations went extinct as the climate cooled, and presently the species is extinct from all central Europe, except few relic populations in locally suitable microhabitats in Germany and the Czech Republic. Our phylogenetic and demographic analyses identified two major clades that expanded from their respective western and eastern refugia after the last glacial maximum (18,000-23,000 years ago) and contributed approximately equally to the present range. Snakes from the relic northern populations carried the Eastern clade, showing that it was primarily the snakes from the eastern, probably Balkan, refugium that occupied the central and northern Europe during the Holocene climatic optimum. Two small, deep-branching clades were identified in near the Black Sea and in Greece. These clades provide evidence for two additional refugia, which did not successfully contribute to the colonization of Europe. If, as our results suggest, some populations responded to the mid-Holocene global warming by shifting their ranges further north than other populations of the same species, knowing what populations were able to expand in different species may provide information about what populations will be important for the species' ability to cope with the current global warming.

• MeSH
• Colubridae klasifikace   genetika   MeSH
• fylogeneze MeSH
• fylogeografie MeSH
• haplotypy MeSH
• mitochondriální DNA genetika   MeSH
• molekulární evoluce MeSH
• podnebí MeSH
• pravděpodobnostní funkce MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

Animals are ancestrally important stimuli for humans who pay disproportional attention to animal objects and exhibit an outstanding ability to categorize animal species, especially those most relevant to them. Humans as well as other primates perceive snakes as ambivalent stimuli that elicit unspecific arousal and attention. We assessed human aesthetic preferences toward milk snakes, the traditional model for studies of Batesian mimicry. The genus is fairly uniform in size and shape, but includes a great variety of color forms; some possessing aposematic patterns while others being rather cryptic. This provides an opportunity to test which features are responsible for positive aesthetic evaluation of the species. We asked the respondents to rank 34 pictures of milk snakes according to perceived beauty. The sets (whole bodies, heads, and skin fragments) covered most of naturally occurring variation in milk snake appearance. While ranking the beauty, the respondents spontaneously classified the species according to two dimensions. In each set, one of the dimensions corresponds to perceived beauty. The respondents' ranking revealed several distinct clusters of species instead of a continuous gradient. The species clustered in a similar way irrespective of evaluated set. One dimension of the ranking associated with the relative representation of red color and the number of transversal stripes, the other corresponded to a low proportion of red and a high proportion of black color. When the whole body of the snake is evaluated, aposematic coloration contributes to its perceived beauty. In conclusion, humans showed a surprising ability to classify milk snake patterns; they repeatedly formed the same distinct groups of species, thus completing a process that resembles unsupervised categorization.

• MeSH
• analýza hlavních komponent MeSH
• Colubridae anatomie a histologie   klasifikace   MeSH
• estetika psychologie   MeSH
• hlava anatomie a histologie   MeSH
• kognice MeSH
• krása MeSH
• kůže anatomie a histologie   MeSH
• lidé MeSH
• molekulární mimikry MeSH
• rozpoznávání obrazu MeSH
• shluková analýza MeSH
• světelná stimulace MeSH
• vnímání barev MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH