Yoland Savriama

Yoland Savriama
Max Planck Institute for Evolutionary Biology · Department of Evolutionary Genetics

PhD in Evolutionary Biology

About

70
Publications
25,691
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
504
Citations
Introduction
Yoland Savriama currently works at the Institute of Biotechnology, University of Helsinki. Yoland does research in Evolutionary Biology, Developmental Biology and Biostatistics. Their most recent publication is 'Additional File 3'.
Additional affiliations
January 2019 - present
Max Planck Institute for Evolutionary Biology
Position
  • PostDoc Position
Description
  • 3D statistical shape analysis of craniofacial features in rats and birds
September 2014 - December 2018
University of Helsinki
Position
  • PostDoc Position
Description
  • Working on seal's teeth and skull with Academy Professor Jukka Jernvall.
May 2013 - September 2014
St. John's University
Position
  • Visiting Scientist
Education
September 2005 - September 2008
The University of Manchester
Field of study
  • Biological Sciences
September 2004 - June 2005
University of Burgundy
Field of study
  • Earth Sciences Palaeontology
September 2002 - June 2003
University of Burgundy
Field of study
  • Earth Sciences

Publications

Publications (70)
Article
Full-text available
Various advances in 3D automatic phenotyping and landmark-based geometric morphometric methods have been made. While it is generally accepted that automatic landmarking compromises the capture of the biological variation, no studies have directly tested the actual impact of such landmarking approaches in analyses requiring a large number of specime...
Article
Full-text available
Molar morphology is shaped by phylogenetic history and adaptive processes related to food processing. Topographic parameters of the occlusal surface, such as sharpness and relief, can be especially informative regarding diet preferences of a species. The occlusal surface can however be deeply modified by wear throughout an animal's life, potentiall...
Preprint
Full-text available
Background Various advances in 3D automatic phenotyping and particularly in landmark-based geometric morphometric methods have been made, but only a few studies have tested the reliability of such automatic procedures in morphometric analyses. It is generally accepted that automatic landmarking compromises the capture of the actual biological varia...
Article
Full-text available
Genic copy number differences can have phenotypic consequences, but this has not been much studied in natural populations so far. We have analyzed here the natural variation of two families of tandemly repeated regulatory small nucleolar RNAs (SNORD115 and SNORD116) in the house mouse (Mus musculus). They are encoded within the Prader-Willi Syndrom...
Chapter
Full-text available
D'Arcy Thompson's work foreshadowed the emergence of a science of forms, one facet of which is a new branch of biometrics, morphometrics, which focuses on the quantitative description of shapes and the statistical analysis of their variations. This chapter describes the morphometric characterization of symmetry and illustrates its applications in b...
Article
Full-text available
Ecomorphological studies evaluating the impact of environmental and biological factors on the brain have so far focused on morphology or size measurements, and the ecological relevance of potential multi-level variations in brain architecture remains unclear in vertebrates. Here, we exploit the extraordinary ecomorphological diversity of squamates...
Article
Full-text available
In the Cabo Verde archipelago, Campanula spp. (bellflowers) are currently represented by four endemic species restricted to mountainous islands (C. bravensis, C. feijoana, C. hortelensis and C. jacobaea), all of which are known for high floral polymorphism. Diagnostic features of the corolla often differ from original descriptions, bringing into qu...
Article
Full-text available
Abstract Symmetry is a pervasive feature of organismal shape and the focus of a large body of research in Biology. Here, we consider complex patterns of symmetry where a phenotype exhibits a hierarchically structured combination of symmetries. We extend the Procrustes ANOVA for the analysis of nested symmetries and the decomposition of the overall...
Article
Full-text available
An increasing number of mammalian species have been shown to have a history of hybridization and introgression based on genetic analyses. Only relatively few fossils, however, preserve genetic material, and morphology must be used to identify the species and determine whether morphologically intermediate fossils could represent hybrids. Because den...
Article
Full-text available
This paper provides a step-by-step guide for the morphological analysis of corolla and the decomposition of corolla shape variation into its symmetric and asymmetric components. The shape and symmetric organisation of corolla are key traits in the developmental and evolutionary biology of flowering plants. The various spatial layout of petals can e...
Preprint
Full-text available
An increasing number of mammalian species have been shown to have a history of hybridization and introgression based on genetic analyses. Only relatively few fossils, however, preserve genetic material and morphology must be used to identify the species and determine whether morphologically intermediate fossils could represent hybrids. Because dent...
Preprint
Full-text available
Symmetry is a pervasive feature of organismal shape and the focus of a large body of research in Biology. Here, we consider complex patterns of symmetry where a phenotype exhibits a hierarchically structured combination of symmetries. We extend the Procrustes ANOVA for the analysis of nested symmetries and the decomposition of the overall morpholog...
Article
Full-text available
From gastrulation to late organogenesis animal development involves many genetic and bio-mechanical interactions between epithelial and mesenchymal tissues. Ectodermal organs, such as hairs, feathers and teeth are well studied examples of organs whose development is based on epithelial-mesenchymal interactions. These develop from a similar primordi...
Data
Implementation of cell-cell mechanical interactions in the EmbryoMaker framework (Marin-Riera et al. 2016). A, Mechanical interactions between spherical nodes (mesenchyme and suprabasal layer) are determined by the distance between their centers and their equilibrium radius (edge of the darker circle). B–D, Mechanical interactions between two epith...
Data
Parameter exploration of different cell mechanical parameters. A parameter exploration was performed by varying the cell incompressibility parameter (pREC) independently for epithelial, suprabasal and mesenchymal cells. A-C show shape variation for different combinations of suprabasal and mesenchymal values of pREC, keeping epithelial pREC constant...
Data
Parameter screening of the tissue specific proliferation rates (sepi, ssup and smes). A, B, C, Variation in tooth germ morphology with different combinations of sepi and ssup, keeping smes constant, under the different hypotheses (frontal sections depicted). In all cases, cervical loops form when sepi is relatively high and ssup is relatively low,...
Data
In silico separation experiments performed with different adhesion parameters. A, B, cap stage tooth germs simulated with different adhesion parameters. C, D, the same tooth germs as in A and B respectively, after the separation. Growth parameters used: sepi = 0.055, ssup = 0.033, smes = 0.245. (PNG)
Data
Time series of the in silico separation shown on Fig 9, depicting mechanical forces at different time points. Colour code indicates mechanical stress, the same as in Figs 7 and 9. (PNG)
Data
The whole growth parameter exploration for hypothesis III in the 3D model. Each panel (A-D) displays model simulations for all the permutations of suprabasal and mesenchymal growth rate values (ssup and smes) for a constant value of epithelial growth rate (sepi). sepi values gradually increase in each subsequent panel. Colouring as in Fig 3. (PNG)
Data
Sensitivity analysis of the 2D model parameter screening. Each plots shows the distribution of the standard error between model and empirical data in log scale (Y axis) separately for the different values of one specific parameter (X axis) as a violin plot. Each violin groups simulation runs with a fixed value of a specific parameter, while the res...
Data
Parameter exploration of differential adhesion parameters. A, Tooth germ morphologies are shown with different combinations of mesenchymal homotypic adhesion and suprabasal homotypic adhesion values, while the other adhesion parameters are set to 1.0. High values of mesenchymal homotypic adhesion result in low growth angles whereas high values of s...
Data
Time series of the three simulations (A-C) shown in Fig 7A–7C, depicting mechanical forces on the mesenchyme (top series for each panel) and the suprabasal layer (bottom series for each panel) at different time points. Top series for each simulation shows only the tooth mesenchyme through a sagittal cut (only the buccal half is displayed). Bottom s...
Data
Growth curve measurements for empirical and in silico data. A, B, individual frames from the time-lapse video (taken from Morita et al. 2016 with permission) that we chose as starting and finishing time points for the measurement. The white segment in A corresponds to the reference unit of length we chose for measuring epithelial perimeter and supr...
Data
Depiction of forces at the interface between epithelium and suprabasal layer and between epithelium and mesenchyme. Epithelial cells are depicted as nodes (small spheres) connected by a spring (green). Thin frontal sections are shown in order to see clearly individual rods (i.e. force mechanical interactions. Parameters used in A, bee = 1.0, bes =...
Data
Depiction of the geometric argument explaining differences in length between AP and BL cervical loops. A, depiction of a simplified 2D tooth germ, seen from below. These could also be seen as tooth germs in which the angle of growth is 180 degrees. The light shade of blue indicates the anterior (A) and posterior (P) parts of the germ, where the A a...
Data
Separation experiment on an E13.5 tooth bud. No major deformation in the epithelial bud is observed, and neither in the surrounding mesenchyme. Dashed line shows the epithelial mesenchymal boundary. Time after immersion in the dispase solution is shown beneath each panel. Scale bar is 200 μm long. (PNG)
Data
Analyses of variance (ANOVAs) for landmark digitizing error in shape and size (i.e. centroid size) for tooth germs and the model. SS, sum of squares; MS, mean square; Df, degrees of freedom; F, F-value; P, P value. (PDF)
Data
Time lapse recording of one separation experiment of six E14.5 tooth germs. Tooth germs were dissected and sectioned into thick slices. Sections were submerged into a dispase solution with the sectioned surface laying flat on the bottom. It can be seen that, as soon as epithelium and mesenchyme detach, the mesenchyme recoils towards one side of the...
Data
Additional information on model design and Methods. (PDF)
Article
Full-text available
The ecological origin of snakes remains amongst the most controversial topics in evolution, with three competing hypotheses: fossorial; marine; or terrestrial. Here we use a geometric morphometric approach integrating ecological, phylogenetic, paleontological, and developmental data for building models of skull shape and size evolution and developm...
Article
Full-text available
Background While floral symmetry has traditionally been assessed qualitatively, recent advances in geometric morphometrics have opened up new avenues to specifically quantify flower shape and size using robust multivariate statistical methods. In this study, we examine, for the first time, the ability of geometric morphometrics to detect morphologi...
Article
Using the centipede model species Strigamia maritima as a subject of study, we illustrate the potential of geometric morphometrics for investigating the development and evolution of segmentation, with a specific focus on post-embryonic segmental patterning. We show how these techniques can contribute detailed descriptive data for comparative purpos...
Article
Full-text available
Does a modular body organization present a challenge for developmental control? We investigate the idea of a possible developmental cost of modularity by examining the relationship between modularity and developmental stability in a multi-segmented arthropod taxon: the geophilomorph centipedes. In a sample of eight species, we tested the correlatio...
Data
The surroundings of the Cortiou sewage are among the most polluted environments of the French Mediterranean Sea (Marseilles, France). So far, no studies have precisely quantified the impact of pollution on the development of organisms in this area.Methods: We used a fluctuating asymmetry (FA) measure of developmental instability (DI) to assess envi...
Article
Full-text available
Matching pairs of skeletal elements is of fundamental importance when re-associating skeletons from commingled settings. This study presents a new method that combines the use of traditional anthropometric size measurements and the analysis of shape, through geometric morphometrics, to form pairs from commingled settings. We tested the hypothesis t...
Article
Symmetry is an important feature of floral structure, and floral symmetries are diverse and often complex. We use a new morphometric approach for analysing shapes with complex types of symmetry, which partitions shape variation into a component of symmetric variation and different components of asymmetry. This approach, based on the mathematical th...
Article
Full-text available
Studies of symmetric structures have made important contributions to evolutionary biology, for example, by using fluctuating asymmetry as a measure of developmental instability or for investigating the mechanisms of morphological integration. Most analyses of symmetry and asymmetry have focused on organisms or parts with bilateral symmetry. This is...
Article
Full-text available
Algal cells show many types of complex symmetry. For instance, Micrasterias rotata cells are symmetric relative to two perpendicular axes of symmetry. Due to the mode of cell division of Micrasterias rotata cells, the symmetry axes can be interpreted as a left-right axis and a juvenile-adult axis. Here, we analyze symmetry and allometry in Micraste...
Article
Local adaptation may be important for the preservation of genetic diversity and the promotion of speciation. However, local adaptation may also constrain establishment in different environments. The consequences of local adaptation depend strongly on the pleiotropic effects of the genes involved in adaptation. Here, we investigated the pleiotropic...

Projects

Project (1)
Archived project