Sökning: "jawed vertebrates"
Visar resultat 1 - 5 av 10 avhandlingar innehållade orden jawed vertebrates.
Sammanfattning : Gnathostomes, or jawed vertebrates, make up the overwhelming majority of modern vertebrate diversity. Among living vertebrates, they comprise the chondrichthyans (“cartilaginous fishes” such as sharks, skates, rays, chimaeras) and the osteichthyans (“bony fishes” or bony vertebrates, inclusive of tetrapods). LÄS MER
Sammanfattning : During the Silurian, the Swedish island Gotland was positioned close to the equator and covered by a shallow sea called the Baltic Basin. The sedimentary rocks (predominantly carbonates) comprising most of the island today were initially formed in this warm sea, and the relatively complete succession of rocks often contains fossil fragments and scales from early vertebrates, including heterostracans, anaspids, thelodonts, osteostracans, acanthodians, and a stem-osteichthyan. LÄS MER
3. Three-dimensional Virtual Histology of Early Vertebrate Scales Revealed by Synchrotron X-ray Phase-contrast Microtomography
Sammanfattning : Vertebrate hard tissues first appeared in the dermal skeletons of early jawless vertebrates (ostracoderms) and were further modified in the earliest jawed vertebrates. Fortunately, histological information is usually preserved in these early vertebrate fossils and has thus been studied for more than a century, done so by examining thin sections, which provide general information about the specific features of vertebrate hard tissues in their earliest forms. LÄS MER
Sammanfattning : Fishes (Superclass Pisces) constitute the most numerous and morphologically diverse vertebrate group, yet only a small fraction of all molecular evolutionary studies concern piscine evolution. This thesis aims to investigate the vertebrate tree, through the analysis of mitochondrial (mt) DNA sequences. LÄS MER
Sammanfattning : Gene regulation implicates an important role in organismal complexity through contributing to phenotypic variation. In my thesis, I studied three diverse components of gene regulatory networks including transcription factors, DNA methylation and microRNAs to elucidate their role in vertebrates. LÄS MER