Search results for "Macroevolution"
showing 4 items of 14 documents
Evolutionary and developmental hypotheses in rodent dentition through time : the adaptive radiation of Arvicolinae (Rodentia)
2014
The evolution of mammalian dentition is defined by profound morphological modifications as occlusion and heterodonty. Among rodents, characterized by a reduced dental formula, arvicolines have a highly derived dentition, with prismatic and hypsodont molars. The aim of this Ph.D thesis is to explore various morphological innovations through developmental and adaptive aspects. Geometric morphometric methods were used on molars, incisors and mandibles to investigate the dynamics of development and evolution of dentition. A developmental model predicting molar proportions is tested and confirmed for the rodent order; it could be also extended to the premolar. The relationship between dental mor…
Spatial patterns of disparity and diversity of the Recent cuttlefishes (Cephalopoda) across the Old World
2003
Aim Diversity and disparity metrics of all Recent cuttlefishes are studied at the macroevolutionary scale (1) to establish the geographical biodiversity patterns of these cephalopods at the species level and (2) to explore the relationships between these two metrics. Location Sampling uses what is known about these tropical, subtropical and warm temperate cephalopods of the Old World based on a literature review and on measurements of museum specimens. Some 111 species spread across seventeen biogeographical areas serve as basic units for exploring diversity and disparity metrics in space. Methods Landmarks describe the shape of the cuttlebone (the inner shell of the sepiids) and difference…
Mollusc shellomes: Past, present and future.
2020
13 pages; International audience; In molluscs, the shell fabrication requires a large array of secreted macromolecules including proteins and polysaccharides. Some of them are occluded in the shell during mineralization process and constitute the shell repertoire. The protein moieties, also called shell proteomes or, more simply, 'shellomes', are nowadays analyzed via high-throughput approaches. These latter, applied so far on about thirty genera, have evidenced the huge diversity of shellomes from model to model. They also pinpoint the recurrent presence of functional domains of diverse natures. Shell proteins are not only involved in guiding the mineral deposition, but also in enzymatic a…
Diversification in evolutionary arenas - assessment and synthesis
2019
Abstract Understanding how and why rates of evolutionary diversification vary is a central issue in evolutionary biology and ecology. The concept of adaptive radiation has attracted much interest, but is metaphorical and verbal in nature, making it difficult to quantitatively compare different evolutionary lineages or geographic regions. In addition, the causes of evolutionary stasis are relatively neglected. Here we review the central concepts in the evolutionary diversification literature and bring these together by proposing a general framework for estimating rates of diversification and quantifying their underlying dynamics, which can be applied across clades and regions and across spat…