| 1. |
- Abalos, Javier, et al.
(författare)
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No evidence for differential sociosexual behavior and space use in the color morphs of the European common wall lizard (Podarcis muralis)
- 2020
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 10:20, s. 10986-11005
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Tidskriftsartikel (refereegranskat)abstract
- Explaining the evolutionary origin and maintenance of color polymorphisms is a major challenge in evolutionary biology. Such polymorphisms are commonly thought to reflect the existence of alternative behavioral or life-history strategies under negative frequency-dependent selection. The European common wall lizard Podarcis muralis exhibits a striking ventral color polymorphism that has been intensely studied and is often assumed to reflect alternative reproductive strategies, similar to the iconic “rock–paper–scissors” system described in the North American lizard Uta stansburiana. However, available studies so far have ignored central aspects in the behavioral ecology of this species that are crucial to assess the existence of alternative reproductive strategies. Here, we try to fill this gap by studying the social behavior, space use, and reproductive performance of lizards showing different color morphs, both in a free-ranging population from the eastern Pyrenees and in ten experimental mesocosm enclosures. In the natural population, we found no differences between morphs in site fidelity, space use, or male–female spatial overlap. Likewise, color morph was irrelevant to sociosexual behavior, space use, and reproductive success within experimental enclosures. Our results contradict the commonly held hypothesis that P. muralis morphs reflect alternative behavioral strategies, and suggest that we should instead turn our attention to alternative functional explanations.
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| 2. |
- Abalos, Javier, et al.
(författare)
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Viability, behavior, and color expression in the offspring of matings between common wall lizard Podarcis muralis color morphs
- 2021
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Ingår i: Current Zoology. - : Oxford University Press (OUP). - 1674-5507 .- 2396-9814. ; 68:1, s. 41-55
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Tidskriftsartikel (refereegranskat)abstract
- Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature. Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis. Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations. Here, we examined the effect of parental morph combination on fertilization success, embryonic viability, newborn quality, antipredator, and foraging behavior, as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis, where color morphs are frequently assumed to reflect alternative phenotypic optima (e.g., alternative reproductive strategies). Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth, survival, and morph inheritance. In agreement with a previous genome-wide association analysis, morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci. Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards, but we found no evidence for the existence of alternative breeding investment strategies in female morphs, or morph-combination effects on offspring viability and behavior. We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P. muralis from the Pyrenees.
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| 3. |
- Cordero, Gerardo A., et al.
(författare)
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Physiological plasticity in lizard embryos exposed to high-altitude hypoxia
- 2017
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Ingår i: JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY. - : Wiley. - 2471-5646 .- 2471-5638. ; 327:7, s. 423-432
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Tidskriftsartikel (refereegranskat)abstract
- Coping with novel environments may be facilitated by plastic physiological responses that enable survival during environmentally sensitive life stages. We tested the capacity for embryos of the common wall lizard (Podarcis muralis) from low altitude to cope with low-oxygen partial pressure (hypoxia) in an alpine environment. Developing embryos subjected to hypoxic atmospheric conditions (15-16% O-2 sea-level equivalent) at 2,877m above sea level exhibited responses common to vertebrates acclimatized to or evolutionarily adapted to high altitude: suppressed metabolism, cardiac hypertrophy, and hyperventilation. These responses might have contributed to the unaltered incubation duration and hatching success relative to the ancestral, low-altitude, condition. Even so, hypoxia constrained egg energy utilization such that larger eggs produced hatchlings with relatively low mass. These findings highlight the role of physiological plasticity in maintaining fitness-relevant phenotypes in high-altitude environments, providing impetus to further explore altitudinal limits to ecological diversification in ectothermic vertebrates.
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| 4. |
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| 5. |
- Feiner, Nathalie, et al.
(författare)
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Vertical transmission of a nematode from female lizards to the brains of their offspring
- 2020
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Ingår i: American Naturalist. - : University of Chicago Press. - 0003-0147 .- 1537-5323. ; 195:5, s. 918-926
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Tidskriftsartikel (refereegranskat)abstract
- Parasites have evolved a diversity of lifestyles that exploit the biology of their hosts. Some nematodes that parasitize mammals pass via the placenta or milk from one host to another. Similar cases of vertical transmission have never been reported in avian and nonavian reptiles, suggesting that egg laying may constrain the means of parasite transmission. However, here we report the first incidence of transovarial transmission of a previously undescribed nematode in an egg-laying amniote, the common wall lizard (Podarcis muralis). Nematodes enter the developing brain from the female ovary early in embryonic development. Infected lizard embryos develop normally and hatch with nematodes residing in their braincase. We present a morphological and molecular phylogenetic characterization of the nematode and suggest that particular features of lizard biology that are absent from birds and turtles facilitated the evolutionary origin of this novel life history.
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| 6. |
- Grassini, Simone, et al.
(författare)
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Pattern matters : Snakes exhibiting triangular and diamond-shaped skin patterns modulate electrophysiological activity in human visual cortex
- 2019
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Ingår i: Neuropsychologia. - : Elsevier. - 0028-3932 .- 1873-3514. ; 131, s. 62-72
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Tidskriftsartikel (refereegranskat)abstract
- The neural and perceptual mechanisms that support the efficient visual detection of snakes in humans are still not fully understood. According to the Snake Detection Theory, selection pressures posed by snakes on early primates have shaped the development of the visual system. Previous studies in humans have investigated early visual electrophysiological activity in response to snake images vs. various alternative dangerous or non-dangerous stimuli. These studies have shown that the Early Posterior Negativity (EPN) component is selectively elicited by snake or snake-like images. Recent findings yielded the complementary/alternative hypothesis that early humans (and possibly other primates) evolved an aversion especially for potentially harmful triangular shapes, such as teeth, claws or spikes. In the present study we investigated the effect of triangular and diamond-shaped patterns in snake skins on the ERP correlates of visual processing in humans. In the first experiment, we employed pictures of snakes displaying either triangular/diamond-shaped patterns or no particular pattern on their skins, and pictures of frogs as control. Participants observed a random visual presentation of these pictures. Consistent with previous studies, snakes elicited an enhanced negativity between 225 and 300 ms (EPN) compared to frogs. However, snakes featuring triangular/diamond-shaped patterns on their skin produced an enhanced EPN compared to the snakes that did not display such patterns. In a second experiment we used pictures displaying only skin patterns of snakes and frogs. Results from the second experiment confirmed the results of the first experiment, suggesting that triangular snake-skin patterns modulate the activity in human visual cortex. Taken together, our results constitute an important contribution to the snake detection theory.
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| 7. |
- Michaelides, Sozos N., et al.
(författare)
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Loss of genetic diversity and increased embryonic mortality in non-native lizard populations
- 2016
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083. ; 25:17, s. 4113-4125
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Tidskriftsartikel (refereegranskat)abstract
- Many populations are small and isolated with limited genetic variation and high risk of mating with close relatives. Inbreeding depression is suspected to contribute to extinction of wild populations, but the historical and demographic factors that contribute to reduced population viability are often difficult to tease apart. Replicated introduction events in non-native species can offer insights into this problem because they allow us to study how genetic variation and inbreeding depression are affected by demographic events (e.g. bottlenecks), genetic admixture and the extent and duration of isolation. Using detailed knowledge about the introduction history of 21 non-native populations of the wall lizard Podarcis muralis in England, we show greater loss of genetic diversity (estimated from microsatellite loci) in older populations and in populations from native regions of high diversity. Loss of genetic diversity was accompanied by higher embryonic mortality in non-native populations, suggesting that introduced populations are sufficiently inbred to jeopardize long-term viability. However, there was no statistical correlation between population-level genetic diversity and average embryonic mortality. Similarly, at the individual level, there was no correlation between female heterozygosity and clutch size, infertility or hatching success, or between embryo heterozygosity and mortality. We discuss these results in the context of human-mediated introductions and how the history of introductions can play a fundamental role in influencing individual and population fitness in non-native species.
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| 8. |
- Michaelides, Sozos, et al.
(författare)
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Phylogeography and conservation genetics of the common wall lizard, Podarcis muralis, on islands at its northern range.
- 2015
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Populations at range limits are often characterized by lower genetic diversity, increased genetic isolation and differentiation relative to populations at the core of geographical ranges. Furthermore, it is increasingly recognized that populations situated at range limits might be the result of human introductions rather than natural dispersal. It is therefore important to document the origin and genetic diversity of marginal populations to establish conservation priorities. In this study, we investigate the phylogeography and genetic structure of peripheral populations of the common European wall lizard, Podarcis muralis, on Jersey (Channel Islands, UK) and in the Chausey archipelago. We sequenced a fragment of the mitochondrial cytochrome b gene in 200 individuals of P. muralis to infer the phylogeography of the island populations using Bayesian approaches. We also genotyped 484 individuals from 21 populations at 10 polymorphic microsatellite loci to evaluate the genetic structure and diversity of island and mainland (Western France) populations. We detected four unique haplotypes in the island populations that formed a sub-clade within the Western France clade. There was a significant reduction in genetic diversity (HO, HE and AR) of the island populations in relation to the mainland. The small fragmented island populations at the northern range margin of the common wall lizard distribution are most likely native, with genetic differentiation reflecting isolation following sea level increase approximately 7000 BP. Genetic diversity is lower on islands than in marginal populations on the mainland, potentially as a result of early founder effects or long-term isolation. The combination of restriction to specific localities and an inability to expand their range into adjacent suitable locations might make the island populations more vulnerable to extinction.
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| 9. |
- Uller, Tobias, et al.
(författare)
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Genetic differentiation predicts body size divergence between island and mainland populations of common wall lizards (Podarcis muralis)
- 2019
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Ingår i: Biological Journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4066 .- 1095-8312. ; 127:4, s. 771-786
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Tidskriftsartikel (refereegranskat)abstract
- Small-bodied vertebrates sometimes evolve gigantism on islands, but there is a lack of consistent association with ecological factors or island characteristics. One possible reason is that, even if the ecological conditions are right, body size might fail to diverge on islands that were isolated recently or if there is gene flow between islands and the mainland. We studied body size, ventral colour polymorphism and genetic structure across nine islands and adjacent mainland populations of common wall lizards (Podarcis muralis) off the western coast of France. Population genetic data suggested that island populations might have maintained gene flow after their geographical isolation from the mainland. Island lizards were larger and heavier than mainland lizards on average, but the extent of gigantism varied substantially between islands. Island size and distance from the mainland were poor predictors of body size, but lizards from populations that were highly genetically differentiated from the mainland were larger than lizards from less differentiated populations. Colour morphs that were rare on the mainland tended to be more common on islands. We propose that genetic isolation or bottlenecks promote body size evolution in island lizards, which makes it challenging to identify ecological causes of island gigantism without complementary genetic information.
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| 10. |
- Yang, Weizhao, et al.
(författare)
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Population Genomics of Wall Lizards Reflects the Dynamic History of the Mediterranean Basin
- 2022
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 39:1
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Tidskriftsartikel (refereegranskat)abstract
- The Mediterranean Basin has experienced extensive change in geology and climate over the past six million years. Yet, the relative importance of key geological events for the distribution and genetic structure of the Mediterranean fauna remains poorly understood. Here, we use population genomic and phylogenomic analyses to establish the evolutionary history and genetic structure of common wall lizards (Podarcis muralis). This species is particularly informative because, in contrast to other Mediterranean lizards, it is widespread across the Iberian, Italian, and Balkan Peninsulas, and in extra-Mediterranean regions. We found strong support for six major lineages within P. muralis, which were largely discordant with the phylogenetic relationship of mitochondrial DNA. The most recent common ancestor of extant P. muralis was likely distributed in the Italian Peninsula, and experienced an "Out-of-Italy" expansion following the Messinian salinity crisis (∼5 Mya), resulting in the differentiation into the extant lineages on the Iberian, Italian, and Balkan Peninsulas. Introgression analysis revealed that both inter- and intraspecific gene flows have been pervasive throughout the evolutionary history of P. muralis. For example, the Southern Italy lineage has a hybrid origin, formed through admixture between the Central Italy lineage and an ancient lineage that was the sister to all other P. muralis. More recent genetic differentiation is associated with the onset of the Quaternary glaciations, which influenced population dynamics and genetic diversity of contemporary lineages. These results demonstrate the pervasive role of Mediterranean geology and climate for the evolutionary history and population genetic structure of extant species.
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