Kostas SagonasAristotle University of Thessaloniki | AUTH · School of Biology
Kostas Sagonas
Postdoc
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38
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Publications (38)
Simple Summary: Insularity shapes many aspects of animal biology, and thermal physiology is not an exception. However, not all islands affect animals in the same way. Here, we aim to shed light on the thermal adaptations that animals attain on small islets of the Aegean Sea, Greece. We compare the thermoregulatory profile of the endemic Milos wall...
The continuing biodiversity loss represents a global environmental crisis and a major challenge for the 21st century, highlighting the need for improved biomonitoring. However, classical survey methods are often prone to human errors due to difficulties in identifying cryptic species and species in early life stages and may be unreliable in identif...
Simple Summary
As ectotherms that do not produce metabolic heat to regulate their body temperature, lizards largely rely on the thermal quality of the environment for most aspects of their biology. To compensate for geographically induced changes in the thermal environment, different lizard populations within a single species should either regulate...
Genome sequencing enables answering fundamental questions about the genetic basis of adaptation, population structure and epigenetic mechanisms. Yet, we usually need a suitable reference genome for mapping population-level resequencing data. In some model systems, multiple reference genomes are available, giving the challenging task of determining...
Genome-level sequencing enables us to ask fundamental questions about the genetic basis of adaptation, population structure, and epigenetic mechanisms, but usually requires a suitable reference genome for mapping population-level re-sequencing data. In some model systems, multiple reference genomes are available, giving researchers the challenging...
This is a pre-print. Currently, the paper is under-review.
You may download it freely from here: 10.2139/ssrn.4578618
Balancing selection describes evolutionary processes that maintain genetic diversity. To date, the number of impacted genes and underlying biological functions remain elusive. Using 60 three-spined stickleback genomes (Gasterosteus aculeatus) from five recently diverged lake-river population-pairs, we performed genome-wide scans across two levels o...
Balancing selection describes evolutionary processes that maintain genetic diversity. To date, the number of impacted genes and underlying biological functions remain elusive. Using 60 three-spined stickleback genomes ( Gasterosteus aculeatus ) from five recently diverged lake-river population-pairs, we performed genome-wide scans across two levels...
Tissue regeneration is a fundamental evolutionary adaptation, which is well known in lizards that can regenerate their entire tail. However, numerous parameters of this process remain poorly understood. Lizard tail serves many functions. Thus, tail autotomy comes with many disadvantages and the need for quick regeneration is imperative. To provide...
Parasites are arguably among the strongest drivers of natural selection, constraining hosts to evolve resistance and tolerance mechanisms. Although, the genetic basis of adaptation to parasite infection has been widely studied, little is known about how epigenetic changes contribute to parasite resistance and eventually, adaptation. Here, we invest...
The genus Pelophylax has been considered a model organism for understanding hybridization. Despite being the most diverse within the Western Palearctic group of Pelophylax , the ridibundus / bedriagae lineage that includes six species, remains largely understudied, revealing many knowledge gaps in regards to their evolution and conservation. Using...
Biodiversity conservation is a global issue where the challenge is to integrate all levels of biodiversity to ensure the long‐term evolutionary potential and resilience of biological systems. Genetic approaches have largely contributed to conservation biology by defining “conservation entities” accounting for their evolutionary history and adaptive...
Studies on life history characters are of pivotal importance to understand population dynamics and demography and, if required, to propose effective conservation measures. The Balkan green lizard (Lacerta trilineata) is the most widespread lizard species in the Balkans but, interestingly, there are no studies on its reproductive biology. Herein, we...
The major histocompatibility complex (MHC) has long served as a model for the evolution of adaptive genetic diversity in wild populations. Pathogen-mediated selection is thought to be a main driver of MHC diversity, but it remains elusive to what degree selection shapes MHC diversity in complex biogeographical scenarios where other evolutionary pro...
Information is provided on the feeding ecology and reproduction of the european Green lizard, Lacerta viridis (Laurenti, 1768), from the very south of its distribution range. The authors analyzed the stomach contents of 86 preserved specimens originating from the Greek mainland stored at the Herpetological collection of the natural History Museum o...
Aim
Animal body sizes are often remarkably variable across islands, but despite much research we still have a poor understanding of both the patterns and the drivers of body size evolution. Theory predicts that interspecific competition and predation pressures are relaxed on small, remote islands, and that these conditions promote body size evoluti...
Species occurring in sympatry have to effectively segregate their niche in order to co-exist. In the case of ectotherms in particular, the very important parameter of thermal biology has to be taken into account. Here we investigated the thermoregulatory effectiveness (E) of two endemic Greek lizards (Hellenolacerta graeca and Podarcis peloponnesia...
Caudal autotomy is one of the most effective and widespread defensive mechanisms among lizards. When
predators grasp the tail, lizards are able to shed it from the point of the attack and further. Numerous factors have
been reported to affect tail-shedding performance such as temperature, age, predation pressure, intraspecific competition
etc. Inte...
In caudal autotomy, lizards shed their tail to escape from an attacking predator. Since the tail serves multiple functions, caudal regeneration is of pivotal importance. However, it is a demanding procedure that requires substantial energy and nutrients. Therefore, lizards have to increase energy income to fuel the extraordinary requirements of the...
The ability for effective, accurate and precise thermoregulation is of paramount importance for ectotherms. Sympatric lizards often partition their niche and select different microhabitats. These microhabitats, however, usually differ in their thermal conditions and lizards have to adapt their thermoregulation behaviour accordingly. Here, we evalua...
The ecological importance of islet endemics are in the front line of conservation efforts and thus the good knowledge of their biology is required. Podarcis levendis is a lacertid lizard, endemic to two rocky islets in the Cretan Sea, Greece, that was raised to specific level in 2008 and since then no data on its biology are available. Here we pres...
The gecko Mediodactylus kotschyi is considered rare in mainland Greece, yet it is very abundant on the Aegean islands. It has been thought to be saxicolous throughout much of its range. In a recent survey on the Pelopon-nese peninsula, however, we encountered it mainly on trees, and with higher frequency than previously reported. We combined our ob...
Environmental temperatures considerably affect the reptilian ability for thermoregulation and harsh climatic conditions may impose a highly effective body temperature regulation to lizards. Such demanding conditions are more common to extreme mainland habitats (e.g. deserts or mountains). To the contrary, islands have more benign climate conditions...
Effective digestion is decisive for survival. In nature, where most animals feed sporadically, high digestive performance guarantees they will gain the most out of their infrequent meals. Larger body size implies higher energy requirements and digestion should function properly to provide this extra energy. Comparing Skyros wall lizards (Podarcis g...
The ability of vertebrates to evolve different defense strategies in response to varying parasitism regimes remains poorly understood. Hosts may adopt two different strategies to defend themselves against parasites: tolerance (hosts alleviate the negative fitness consequences of parasite infection) and resistance (hosts strengthen their immune resp...
Purpose During the last three decades, the number of devices that emit non-ionizing electromagnetic radiation (EMR) at the wireless communication spectrum has rapidly increased and possible effects on living organisms have become a major concern. The purpose of this study was to investigate the effects of radiofrequency EMR emitted by a widely used...
Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan gr...
Although rapid evolution of body size on islands has long been known, the ecological mechanisms behind this island phenomenon remain poorly understood. Diet is an important selective pressure for morphological divergence. Here we investigate if selection for novel diets has contributed to the multiple independent cases of island gigantism in the Sk...
The Balkan green lizard (Lacerta trilineata) is the most widespread lizard in the Balkans, ranging from Croatia to Crete and from Ionian to Black Sea. Surprisingly, its feeding ecology remains largely understudied. In this study we describe the diet of the species using 288 specimens from museum collections that derived from 8 island and 4 mainland...
Island environments differ with regard to numerous features from the mainland and may induce large-scale changes in most aspects of the biology of an organism. In this study, we explore the effect of insularity on the morphology and performance of the feeding apparatus, a system crucial for the survival of organisms. To this end, we examined the he...
The overall biology of ectotherms is strongly affected by the thermal quality of the environment. The particular conditions prevailing on islands have a strong effect on numerous features of animal life. In this study we compared mainland and island populations of the lizard Lacerta trilineata and hypothesized that insularity would affect the therm...
Grazing of goats on Mediterranean islets is a common practice. Its consequences on plant communities are well documented, although not on vertebrates. We aim to shed light on the effect of livestock farming on lizards by investigating five populations of the insular lizard, Podarcis gaigeae, differing in the duration and intensity of grazing. Data...
Body size shapes the overall biology of organisms. We assessed the impact of size on temperature
regulation in populations of normal-sized and large-bodied insular Mediterranean lizards (Podarcis
gaigeae, Lacertidae). We hypothesized that large lizards would achieve higher body temperatures and
thermoregulate more effectively than their smaller kin...
Differences in ecological conditions can result in the evolution of dramatic inter-population shifts in whole suites of traits. We studied variation in reproductive output in three lizard populations of the Skyros Wall Lizard {Podareis galgeae, Lacertidae) endemic to the Skyros Archipelago (Greece), which live under similar climatic conditions but...
Differences in ecological conditions can result in the evolution of dramatic inter-population shifts in whole suites of traits. We studied variation in reproductive output in three lizard populations of the Skyros Wall Lizard (Podarcis gaigeae, Lacertidae) endemic to the Skyros Archipelago (Greece), which live under similar climatic conditions but...