Estimating the phylogeny of geoemydid turtles (Cryptodira) from landmark data: an assessment of different methods
      
      
        
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
        
        Published in:
        
          
            
            - PeerJ. - 2019, vol. 7, p. e7476
 
       
      
      
      
       
      
      
      
        
        English
        
        
        
          Background: In the last 20 years, a general picture of the evolutionary relationships  between geoemydid turtles (ca. 70 species distributed over the Northern hemisphere)  has emerged from the analysis of molecular data. However, there is a paucity of good  traditional morphological characters that correlate with the phylogeny, which are  essential for the robust integration of fossil and molecular data. Part of this problem  might be due to intrinsic limitations of traditional discrete characters. Here, we explore  the use of continuous data in the form of 3D coordinates of homologous landmarks on  the turtle shell for phylogenetic inference and the phylogenetic placement of single  species on a scaffold molecular tree. We focus on the performance yielded by  sampling the carapace and/or plastral lobes and using various phylogenetic  methods.Methods: We digitised the landmark coordinates of the carapace and  plastron of 42 and 46 extant geoemydid species, respectively. The configurations  were superimposed and we estimated the phylogenetic tree of geoemydids with  landmark analysis under parsimony, traditional Farris parsimony, unweighted squared- change parsimony, maximum likelihood with a Brownian motion model, and  neighbour-joining on a matrix of pairwise Procrustes distances. We assessed the  performance of those analyses by comparing the trees against a reference phylogeny  obtained from seven molecular markers. For comparisons between trees we used  difference measures based on quartets and splits. We used the same reference tree  to evaluate phylogenetic placement performance by a leave-one-out validation  procedure.Results: Whatever method we used, similarity to the reference phylogeny  was low. The carapace alone gave slightly better results than the plastron or the  complete shell. Assessment of the potential for placement of single species on the  reference tree with landmark data gave much better results, with similar accuracy and  higher precision compared to the performance of discrete characters with parsimony.
        
        
       
      
      
      
        
        
        
        
        
        
        
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          Faculty
          
        
- Faculté des sciences et de médecine
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          Department
          
        
- Département de Géosciences
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          Classification
        
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                  Palaeontology
                
              
            
          
        
- Other electronic version
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          Persistent URL
        
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          https://folia.unifr.ch/unifr/documents/308148
        
 
   
  
  
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