Geographical Variability in Common Hamster Mandibles, Cricetus cricetus (Linnaeus, 1758)

V diplomski nalogi smo analizirali geografsko variabilnost mandibule velikega hrčka. V analizo smo vključili 217 mandibul iz treh geografskih območij (nemški in srbski vzorec predstavljata evropsko geografsko območje, ruski vzorec predstavlja azijsko geografsko območje). Vsaki mandibuli smo priredili 16 oslonilnih točk in izvedli analizo velikosti in oblike s pomočjo metod geometrijske morfologije. V sklopu naloge smo preverjali sekundarni spolni dimorfizem. Rezultati analize variabilnosti velikosti in oblike izkazujejo signifikantno razliko med samci in samicami pri evropskem vzorcu (od evropskih živali smo vključili samo osebke iz nemškega vzorca z znanim spolom). Pri ruskem vzorcu nismo potrdili sekundarnega spolnega dimorfizma. Menimo, da so za razjasnitev tega fenomena potrebne nadaljnje študije. Različen vzorec v velikosti in obliki mandibule nemškega in ruskega vzorca lahko razlagamo na podlagi vpliva habitata. Morebiten vpliv starostne variabilnosti na velikost in obliko mandibule smo izločili, saj analize variabilnosti v kombinaciji s starostjo, spolom in geografskim območjem izvora mandibul ne izkazujejo statistične signifikantnosti. V zadnjem raziskovalnem poglavju smo obravnavali geografsko variabilnost mandibule velikega hrčka. Rezultati analize variabilnosti tako v velikosti, kot obliki so pokazali, da prihaja do razlik med vsemi tremi geografskimi območji. V velikosti se razlikujeta evropski in azijski vzorec, pri čemer smo prišli do zaključka, da so ruski hrčki večji. Srbski in nemški vzorec sta po velikosti precej podobna. V obliki prihaja do največjih razlik na veji mandibule, kjer so koronoidni, kondilarni in angularni izrastki.The purpose of this research was to analyse the geographical variability of mandibles in common hamsters. Our analysis included 217 mandibles from three geographical regions (the German and Serbian samples represent the geographical area of Europe, while the Russian sample represents the geographical area of Asia). We assigned 16 landmark points to each mandible, and used methods of geometric morphometrics to determine their size and shape. As part of our research we also examined secondary sexual dimorphism. Our analysis of size and shape variability showed a significant difference between male and female hamsters in the European sample (among the European animals we only included German specimens where the sex was known). We did not confirm secondary sexual dimorphism in the Russian sample, and we believe that the clarification of this phenomenon requires further research. The differences in the size and shape of German and Russian mandibles are most likely a result of the impact of habitat. We excluded the possibility of the variable of age having an impact on size and shape, since the analysis of variables, in combination with age, sex, and the mandibles\u27 geographical region of origin, did not exhibit statistical significance. The last section of our research deals with the geographical variability of mandibles in large hamsters. The results of our analysis on size and shape variability showed that differences occur among all three geographical regions. The European and Asian samples differed in size, which lead us to believe that Russian hamsters are larger than their European counterparts, while the Serbian and German samples were very similar in size. The greatest differences in shape were found in the coronoid and condylar process and the angle of the mandible