Major professional aims and interests
I have a life-long fascination with the complexity and diversity of biological shapes in animals, which range from relatively simple to the most intricate forms. My main interest is to study the mechanistic principles of biological shape changes during evolution. As all animal shapes arise through the developmental process, it is critical to understand the relationship between evolution and development. Intellectually, I am a disciple of Karl von Baer, D’Arcy Thompson, Ivan Schmalhausen, C.H. Waddington, Stephen J. Gould and Pere Alberch, who all believed that a successful exploration of many evolutionary phenomena relies on the deeper understanding of the connection between the phylogeny and ontogeny and learning the principles upon which the organisms are constructed during individual development. In modern developmental evolution field research,
I distinguish three distinct but highly interdependent components:
- (i) morphometrics to reveal the kind and direction of morphological change within a given phylogeny,
(ii) identification of candidate mechanisms that correlate with evolutionary changes, and
(iii) functional experiments which causally link developmental changes with morphological transitions.
In my own work, I take a cross-disciplinary and highly collaborative approach that integrates the three evo-devo research components and combines advances from disparate fields, such as phylogenetics, genomics, paleontology, morphometrics, cell biology, and developmental genetics to gain mechanistic understanding of morphogenesis and evolutionary processes that generate morphological variation.
A combination of geometric morphometrics, comparative molecular embryology and functional experimentation methods helps us address many important evolutionary questions and groups of organisms (central diagram from Mallarino and Abzhanov, 2012). My projects on non-model species follow this scheme and they are in different stage of progression from morphological studies (blue) to identification of associated candidate developmental mechanisms (orange) to their experimental testing (green). My major devo-evo projects are several diverse groups of vertebrates: 1) Darwin’s Finches and tanager relatives, 2) Hawaiian Honeycreepers’ beak diversity; 3) non-avian to avian dinosaur large-scale transition; 4) skull diversification and dimorphism in anole lizards; and 5) diverse faces of phyllostomid bat ecomorphs.
The principal focus for my studies is on the vertebrate face and head. Vertebrate head is the most complex part of the body and cranial diversity in vertebrates is an inviting and challenging research topic as animal crania show many unique and adaptive features which reflect their natural history. Most of the head diversity depends on the shapes and sizes of the bones and cartilages that make up the cranial skeleton. Thus, studies on craniofacial skeletal development in “model” (laboratory-bred species) and “non-model” (wild species) animals are fundamental to understanding mechanisms that generated cranial diversity during vertebrate evolution and continue to generate morphological variation today. They are also critical to the advancement of future diagnoses and treatments of human craniofacial disorders. Even though many of the species I study cannot be established in the laboratory, they remain extremely important “natural experiments” and should be explored mechanistically.
My group studies non-model organisms to understand how morphological evolution arose under natural conditions and selective pressures, and I use model organisms to study the underlying developmental principles and to functionally test roles of candidate genes identified in comparative studies. The main reason for my studying multiple non-model species in parallel is to recognize common principles and mechanisms as different taxa can give insights into different aspects of the great puzzle of adaptive evolution that I wish to understand.
Dr Anjan Bhullar, Yale University, Evolution of cranial diversity in Archosauria., 2020
Dr Mark Ravinet, University of Nottingham, Evolution of beak morphology in sparrows., 2019
Dr Anthony Herrel, Natural History Museum, Paris, Development, structure and evolution of osteoderms in lizards., 2018
Dr Susan Evans, University College London, Development, structure and function of osteoderms., 2018
Dr Mahadevan, Harvard Univeraity, Mathematical and biological mechanisms of morphogenesis., 2018
Dr Anjali Goswami, Natural History Museum, London, Evolution of cranial modulatiry., 2017
Dr Jor Tobias, Imperial Collegen London, Phylogenetic analyses of avian evolution., 2017
Dr Leif Andresson, Uppsala University (Sweden), Evolution of beak diversity in Darwin;'s finches., 2017
Dr Yanis Bouchenak-Khelladi, University de Bourgogne, Dijon, France, Phylogenetic analysis of avian adaptive radiations., 2016
Colin Stevenson, Crocodiles of the World, Evolution of cranial diversity in crocodilians., 2016
Dr Stephanie E. Pierce, Harvard University, Evolution of cranial diversity in crocodillians., 2015
Dr Guojie Zhang, University of Copenhagen and China National Genebank at BGI-Shenzhen, Evolution of avian beak diversity., 2015
Dr Kent A. Vliet[, University of Florida, Evolution of cranial diversity in crocodillians., 2014
Dr Nancy Simmons, American Museum of Natural History, New York, Evolution fo cranial diversity in phyllostomid bats., 2013
Dr Helen james, Smithsonian Institute and Natural History Museum, Washington, DC, Evolution of beak diversity in Hawaiian Honeycreepers., 2013
Dr Behringer, University of Texas, Evolution of cranial diversity in phyllostomid bats., 2013
Drs Peter and Rosemary Grant, Princeton University, Evolution of beak shapes in Darwin;'s finches., 2000
How and why biological shapes change during evolution: from D’Arcy Thompson to developmental genetics, The Linnean Society of London, London, UK, 2020
Phylogenetic evidence and ontogenetic mechanisms for evolvability in avian adaptive radiations, St Andrews University, Scotland, UK, 2020
Shaping the faces of Darwin's finches and phyllostomid bats: developmental mechanisms of two famous adaptive radiations., Fondation des Treilles, Tourtour, Nice, France, 2019
Shaping the beaks of Darwin's finches: developmental mechanisms of the famous adaptive radiation, "Darwin’s Day" symposium organised by Norway Sciences Academy at the University of Oslo, Oslo, Norway, 2019
Developmental Evolution of the Animal Face: evolvability, heterochrony and novelty, Lund University, Lund, Sweden, 2018
Developmental Evolution of the Animal Face: from Principles to Mechanisms, University of Sheffield, Sheffied, UK, 2017
Evolution of the Animal Face: from Principles to Mechanisms, University of Basel, Basel, Switzerland, 2017
Principles and mechanisms of beak shape evolution: insights from Darwin’s finches and other songbirds, Queen Mary U of London, London, UK, 2017
Evolution of the Animal Face: from Principles to Mechanisms, The Roslin Institute, Edinburgh, Scotland, 2017
Developmental Evolution of the Animal Face: from Principles to Mechanisms, Pontificia Universidad Católica del Ecuador, Quito, Ecuador, 2017
Evolution of the Animal Face: from Principles to Mechanisms, Centro Andaluz de Biología del Desarrollo (CABD), Universidad Pablo de Olavide,, Seville, Spain, 2016
Cranial Evolution and Diversity, Joint Evolution/Ecology and Molecular/Cell Biology programmes Seminar, Chargé de recherche CNRS, Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Montpellier, France, 2016
Cranial Development and Evoution, University College London (UCL), London, UK, 2016
Evolution and development of the Face, University of Cambridge, Cambridge, UK, 2016
Cranial development and evolution, Department of Craniofacial Development and Stem Cell Biology, King's College London, London, UK, 2016
Evolution and development of the Face, University of Iceland, Reykjavik, Iceland, 2016
Cranial Evolution and Development, Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG),, Dresden, Germany, 2015
Craniofacial evolution and development, Department of Zoology, Oxford University, Oxford, UK, 2015
Research Student Supervision
Cabocel,V, Mapping the diversity of pterosaur crania from phylogenetic and ontogenetic perspectives using geometric morphometrics
Coidan,WD, Evolution of Crocodilian Skull Shape with Relation to Ecology and Behavior
Gleeson,A, Assessing the Complexity and Diversity of the Internal Cranial Sutures of Salamanders, Crocodiles and Caecilians.
Hiu Wai,L, Cranial sutures and evolution of skull composition in archosaurs.
Horton,J, An Anatomical Network Analysis of Crocodilian skull ecomorphology and modularity
Ip,KY, Behind the adaptive radiation of Hawaiian honeycreepers: morphometric and eco-evolutionary comparisons to other passerines
Kerr,MR, A geometric morphometric approach for looking at crocodilian development, and its applications for ageing fossil taxa
Rai,S, Developmental mechanisms underlying the evolution of cranial morphological diversity in Crocodylians
Reaney,A, Phylogenetic analysis if avian adaptive radiations.
Richardson,R, The Origin and Evolution of Vertebrate Cranial Sutures: Assessing the Morphological Diversity of Sutures in Early Tetrapods
Wai Lee,H, Preliminary Study of Structural Complexity and Modularity in Archosaurs using Anatomical Network Analysis
Whitlock,M, Does the addition of the third dimension facilitate any additional insight into the evaluation of Crocodilian skull morphology?
Zhang,Y, Dietary composition across modern crocodilians