Publications by Year: 2014

Anastopoulou I, Eliopoulos C, Valakos ED, Manolis SK. Application of Purkait's triangle method on a skeletal population from southern Europe. Forensic Sci Int. 2014;245:203.e1-4.Abstract
The existence of sexual dimorphism in individual elements of the human skeleton allows sex determination and significantly enhances the identification of fragmentary skeletal material. Traditionally, the pelvis and the skull are used for an accurate sex determination. Sometimes they are not available and alternative methods have to be used. The aim of this work is to study the sexual dimorphism of the proximal portion of the posterior femur by analyzing the biometric data of the Purkait's triangle. The studied sample comprises 203 individuals (112 males and 91 females) from the Modern Human Skeletal Reference Collection (The Athens Collection) of the Department of Animal & Human Physiology (National & Kapodistrian University of Athens). The biometric data were analyzed by Discriminant Analysis and equations were generated for sex determination, which gave an overall correct classification of 78.3%. For the right and the left femur the percentages of correct classification were 77.8% and 75.9% respectively. These accuracy rates were compared to those of an Indian population and were found to be lower (86.5% for males and 86.3% for females). The study of sexual dimorphism (SD) in Greek, Indian, European-American and African-American populations gave interesting results. The AB diameter in the Greek sample shows the lowest degree of SD while the AC diameter shows the highest. In the other three population samples, the BC diameter shows the highest degree of SD. We assume that the femur anatomy of the Greeks is the major cause that the Purkait method does not give high rates of correct classification. It is therefore advisable that practitioners exercise caution when using this method on skeletal material from Greece, especially in forensic contexts.
Sagonas K, Poulakakis N, Lymberakis P, Parmakelis A, Pafilis P, Valakos ED. Molecular systematics and historical biogeography of the green lizards (Lacerta) in Greece: Insights from mitochondrial and nuclear DNA. Molecular Phylogenetics and Evolution. 2014;76:144-154.
Sagonas K, Pafilis P, Lymberakis P, Donihue CM, Herrel A, Valakos ED. Insularity affects head morphology, bite force and diet in a Mediterranean lizard. Biological Journal of the Linnean Society. 2014;112:469-484.Abstract
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 head morphology and feeding ecology of island and mainland populations of the Balkan green lizard, Lacerta trilineata. We predicted that head morphology, performance and diet composition would differ between sexes and habitats as a result of varying sexual and natural selection pressures. We employed geometric morphometrics to test for differences in head morphology, measured bite forces and analysed the diet of 154 adult lizards. Morphological analyses revealed significant differences between sexes and also between mainland and island populations. Relative to females, males had larger heads, a stronger bite and consumed harder prey than females. Moreover, island lizards differed in head shape, but not in head size, and, in the case of males, demonstrated a higher bite force. Islanders had a wider food niche breadth and included more plant material in their diet. Our findings suggest that insularity influences feeding ecology and, through selection on bite force, head morphology. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, ●●, ●●–●●.
Kotsakiozi P, Parmakelis A, Aggeli I-K, Gaitanaki C, Giokas S, Valakos ED. Water balance and expression of heat-shock protein 70 in Codringtonia species: A study within a phylogenetic framework. Journal of Molluscan Studies. 2014;doi: 10.1093/mollus/eyu042.Abstract
Seasonal differences in the water content of fourCodringtoniaspecies were investigated using specimens collected from the field. In addition, rate of water loss and expression of heat-shock protein 70 (Hsp70) were measured in a laboratory setting with sixCodringtoniaspecies subjected to a short-term heat shock. Using a phylogenetic framework, both the Hsp70 expression levels and the rate of water loss were inves tigated for their correlation with spatial and climatic variables. As indicated by the field-collected samples, during summer aestivation only C. helenaeexhibited a tendency for water loss. During the short-term heat shock the rate of water loss inC. helenaewas also significantly greater. No interspecific differences could be detected in the levels of Hsp70 in the species subjected to short-term heat shock. A singleCodringtoniaspecies seemed to maintain increased Hsp70 protein levels. In the species subjected to short-term heat shock, a positive relationship was found between Hsp70 levels and rate of water loss. On the other hand, the Hsp70 levels under normal conditions showed a negative correlation with altitude and mean summer precipitation of the sampling localities. Thus, species seem to adapt to harsher environmental conditions by maintaining higher levels of Hsp70.