Sökning: "Geometric Morphometrics"

Hittade 4 avhandlingar innehållade orden Geometric Morphometrics.

1. 1. Conodont biostratigraphy, taxonomy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia - with focus on meteorite and extraterrestrial chromite-rich strata

   Författare :Johanna Mellgren; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conodonts; biostratigraphy; taxonomy; palaeoecology; morphometrics; extraterrestrial chromite; meteorites; Darriwilian; Middle Ordovician; Baltoscandia;

   Sammanfattning : This thesis deals with conodont biostratigraphy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia, with focus on limestone strata showing traces of the ~ 470 Ma L-chondrite parent body break-up. The evidence for this cosmic event includes abundant centimeter to decimeter-sized fossil meteorites and elevated levels of sediment-dispersed extraterrestrial L-type chromite found in a stratigraphical interval corresponding to the uppermost Lenodus antivariabilis, the L. LÄS MER

3. 2. The development of resource polymorphism – Effects of diet, predation risk and population dynamical feedbacks

   Författare :Jens Andersson; Lennart Persson; André M. De Roos; Umeå universitet; []
   Nyckelord :body shape; diet; geometric morphometrics; phenotypic plasticity; population dynamics; predation risk; resource polymorphism; size structured populations;

   Sammanfattning : This thesis deals with the evolution of individuals within a species adapted to utilize specific resources, i.e. resource polymorphism. Although a well-known phenomenon, the understanding of the mechanisms behind is not complete. LÄS MER

4. 3. 100 million years of shark macroevolution : A morphometric dive into tooth shape diversity

   Författare :Mohamad Bazzi; Per Ahlberg; Matt Friedman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sharks; Macroevolution; Extinction recovery dynamics; Geometric Morphometrics; Morphospace-Disparity Framework; Teeth; Biology with specialization in Evolutionary Organismal Biology; Biologi med inriktning mot evolutionär organismbiologi;

   Sammanfattning : Few vertebrate clades exhibit the evolutionary longevity and versatility of sharks, which constitute nearly half of all current chondrichthyan biodiversity and represent an ecological diversity of mid-to-apex trophic-level predators in both marine and freshwater environments. The rich fossil record of shark teeth from Mesozoic and Cenozoic rocks also makes the group amenable to large-scale quantitative analyses. LÄS MER

5. 4. The Interplay Between Selection And Constraints On Adaptive Divergence And Phenotypic Evolution

   Författare :Fabrice Eroukhmanoff; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Selection; Constraints; Adaptive Divergence; G-matrix; Gene Flow.; Speciation;

   Sammanfattning : Under natural or sexual selection, individuals with advantageous traits or combinations of traits will be more successful than their peers at surviving and/or reproducing. Provided these traits are heritable, meaning that they have a genetic basis, the traits combinations which are selected for, will increase in frequency in the population. LÄS MER