Medvrstna variabilnost lobanje cokorjev, Mylospalax (Mammalia: Rodentia)

Ferlič, Blaž

| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

First page > Show document

Show document

Title:	Medvrstna variabilnost lobanje cokorjev, Mylospalax (Mammalia: Rodentia)
Authors:	ID Ferlič, Blaž (Author) ID Janžekovič, Franc (Mentor) More about this mentor... ID Kryštufek, Boris (Comentor)
Files:	UN_Ferlic_Blaz_2016.pdf (1,53 MB) MD5: 2EA4DEF382F3A5EEDEC8574D3D81229A
Language:	Slovenian
Work type:	Undergraduate thesis
Typology:	2.11 - Undergraduate Thesis
Organization:	FNM - Faculty of Natural Sciences and Mathematics
Abstract:	Tema diplomskega dela je bila analiza variabilnosti lobanj treh vrst cokorjev: M. aspalax, M. myospalax in M. psilurus. Vir podatkov je predstavljalo 250 fotografij lateralne strani lobanje cokorjev razdeljenih v 6 operacijskih taksonomskih enot oz. OTU-jev. S pomočjo metod geometrijske morfometrije in statističnih analiz smo preverjali, ali se lobanje razlikujejo med vrstami, glede na sekundarni spolni dimorfizem in glede na geografski izvor. Najprej smo določili 19 oslonilnih točk na lateralni strani lobanje, nato pa opravili uni- in multivariatne analize. Pri geometrijski morfometriji obravnavamo in analiziramo podatke o velikosti in obliki objektov ločeno, kar smo storili tudi mi. Ugotovili smo, da sekundarni spolni dimorfizem v velikosti ni izražen, v obliki lobanje pa obstajajo razlike, ki pa niso zelo izrazite. Potrdili smo, da so med različnimi vrstami cokorjev iz različnih geografskih lokalitet prisotne razlike v velikosti lobanj. Največje lobanje so imeli M. myospalax iz Tomska, najmanjše pa M. aspalax iz Zabajkalje. Z analizo glavnih komponent (PCA) in diskriminantno analizo smo preverjali variabilnost v obliki lobanj. Prišli smo do zaključka, da se lobanje različnih vrst prav tako razlikujejo po obliki. Opazno pa je tudi razlikovanje med lobanjami iste vrste iz različnih geografskih območji. Razlike smo nato predstavili z vizualizacijo regresije točk na prvo diskriminantno funkcijo. Ugotovili smo, da se med seboj najbolj razlikujeta OTU-ja M. myospalax-Tomsk in M. aspalax-Zabajkalje. To ustreza pričakovanjem, saj gre za dve različni vrsti, ki prihajata iz različnih geografskih območji. Lobanje znotraj vrste M. myospalax med različnimi geografskimi območji se najbolj razlikujejo glede na višino lobanje, pozicijo anteriornega dela zigomatičnega loka, dolžino predčeljustnice, ter pozicijo osnove zatilnega čvršča in bobničnega mehurja. OTU Kazahstan izkazuje najmanjše odstopanje od povprečne vrednosti, OTU Novosibirsk pa največje.
Keywords:	Myospalax aspalax, Myospalax myospalax, Myospalax psilurus, lateralna stran lobanje, geometrijska morfometrija, sekundarni spolni dimorfizem, geografska variabilnost, medvrstna variabilnost
Place of publishing:	Maribor
Publisher:	[B. Ferlič]
Year of publishing:	2016
PID:	20.500.12556/DKUM-63862
UDC:	599.323.7(043.2)
COBISS.SI-ID:	22753544
NUK URN:	URN:SI:UM:DK:NS0BBZX9
Publication date in DKUM:	11.11.2016
Views:	1590
Downloads:	186
Metadata:
Categories:	FNM
:	Copy citation

Average score:	(0 votes)
Your score:	Voting is allowed only for logged in users.
Share:

Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Secondary language

Language:	English
Title:	Interspecies variability of the skull of Zokors, Mylospalax (Mammalia: Rodentia)
Abstract:	The focus of my graduation thesis was the analysis of the variability of the skull in three different species of Zokors: M. aspalax, M. myospalax in M. psilurus. The sources of data were 250 photographs of the lateral view of the skull of the three species. We divided the specimens into 6 distinct Operational taxonomic units (OTU). The aim of the thesis was to analyse the skulls with the method of geometric morphometry. We wanted to find out if the skulls show differences in regard to, secondary sexual dimorphism, geographical origin and interspecies differences. First we determined the location of 19 landmarks that we placed on prominent and easy recognizable features of the lateral view of the skull. With all the landmarks in place on all specimens we performed a number of univariate and multivariate analyses. In geometric morphometrics we analyse the shape and the size of objects independent from each other. We found that secondary sexual dimorphism in regard to size were not present in our samples. There were however small differences in shape between the male and female samples. We confirmed the presence of size differences between the species from different geographic locations. The biggest skulls were present in the OTU M. myospalax-Tomsk, while the smallest where from the OTU M. aspalax-Zabajkalje. We tested the variability in the shape of the skull with the Principal Component Analysis (PCA) and the discriminant analysis. We came to the conclusion that the skulls form different species also differ in their respective shapes. We also determined that there are differences in the skulls from the same species which came from different geographical locations. We then displayed the differences with the visualization of the regression points in regards to the first discriminant function. We concluded that the skulls of OTU M. myospalax-Tomsk and M. aspalax-Zabajkalje displayed the largest amount of differences compared to each other. This meets our expectations, because they are two different species which also come from two different locations. We can also see that the skulls within the species M. myospalax differ from each other in regards to the height of the sagittal crest, the position of the anterior part of the zygomatic arch, the length of the premaxilla and the position of the base of the occipital condyle and the tympanic bulla.
Keywords:	Myospalax aspalax, Myospalax myospalax, Myospalax psilurus, lateral view of the skull, geometric morphometry, secondary sexual dimorphism, geographic variability, interspecies variability

Comments

Leave comment

You must log in to leave a comment.

Comments (0)

0 - 0 / 0

There are no comments!

Back