Abstract Adaptive radiation, or the rapid evolution of morphologically and ecologically diverse species from a single ancestor, usually implies two coincidental processes: multiplication of species number (species richness) and increased phenotypic
Adaptive radiation, or the rapid evolution of morphologically and ecologically diverse species from a single ancestor, usually implies two coincidental processes: multiplication of species number (species richness) and increased phenotypic disparity (morphological diversification). The importance of adaptive radiation as an evolutionary phenomenon was first recognized by George Gaylord Simpson in “The Major Features of Evolution”. Much of the current species richness, ecological and morphological diversity in such clades as birds, angiosperms and mammals, is the result of multiple radiation events. Thus, understanding the causes and constraints of adaptive radiations is critical in the study of the evolution of diversity. We investigate the relative significance for intrinsic and extrinsic factors in avian diversifications and we reveal how the developmental genetic mechanisms controlling adaptive cranial shapes themselves evolved. In our work, we combine phylogenetics, transcriptomics, comparative embryology and functional experimentation to understand how morphological diversity is generated and maintained from phylogenetic and ontogenetic perspectives.
Dr Arkhat Abzhanov is a Reader in Evolution and Developmental Genetics at Imperial College London. His research group is interested in a variety of topics related to the vertebrate craniofacial (head) development, craniofacial genetic conditions in humans and craniofacial developmental evolution. His group uses morphometric, molecular, cellular and genetic approaches to study the precise mechanisms of cranial skeletal cell differentiation and skull/face morphogenesis in amniotes. The species they work with range from the laboratory “model” systems, such as chicken embryos and mouse mutants, to the “non-model” species used for evolutionary developmental studies, for example, Darwin’s Finches and their relatives from Caribbean Islands, as well as other birds and, more recently, reptiles, both squamates (e.g. Anolis lizards), and archosaurs, such as alligators. This combination of laboratory “model” species with “non-model” species from natural environments allows us to address important conceptual questions, such as the roles of particular developmental genetic mechanisms (e.g. modularity) in evolution of adaptive variation and significant morphological transitions at both small and large evolutionary scales.
Generally, their studies on evolutionary developmental biology (Evo-Devo) have a tripartite structure of the overall approach: 1) The first step is quantification of morphological variation using methods ranging from simply scoring the absence or presence of particular structures to 3D imaging and modeling; 2) The second component is identification of candidate genetic and developmental mechanisms using methods ranging from observations of the trait as it emerges in real time to quantitative trait locus (QTL) mapping to microarray and RNAseq screens;3) The third part is functional assays of candidate genes/pathways to reveal the more causative relationships by methods ranging from physical manipulations to tissue and embryo transgenesis with molecular vectors.
If you would like to talk to Arkhat, please contact David Ferrier.
(Tuesday) 1:00 pm - 2:00 pm
Carolin Kosiol, Shoko Sugasawa, & Nora Carlsonck202@st-andrews.ac.uk, email@example.com, firstname.lastname@example.org Dyers Brae, University of St Andrews, St Andrews, Fife, KY16 9TH, UK