Darwin Day abstracts
40 Years of Evolution: Darwin’s finches on Daphne Major Island
Speakers: Peter R. Grant & B. Rosemary Grant, Princeton University (USA)
Abstract: In the “Origin of Species” Charles Darwin established the scientific basis for understanding how evolution occurs by natural selection. To explain how species form he envisioned a three-step process: colonization, involving the expansion of a population into a new environment; divergence, when populations become adapted to novel environmental conditions through natural selection; and finally, the formation of a barrier to interbreeding between divergent lineages. He showed characteristic insight by suggesting that investigations of what we now call “very young adaptive radiations” might provide windows through which we can view the processes involved. Since Darwin’s time insights from the fields of genetics, behavior and ecology have continued to illuminate how and why species evolve. In this talk we will discuss the progress that has been made in our understanding of speciation with special reference to the young radiation of Darwin’s Finches. We draw upon the results of a long-term field study of finch populations spanning several decades, combined with laboratory investigations of the molecular genetic basis of beak development.
Shaping the beaks of Darwin's finches: developmental mechanisms of the famous adaptive radiation
Speaker: Arkhat Abzhanov, Imperial College London and Natural History Museum (UK)
Abstract: Darwin’s finches are a classical, textbook example of adaptive radiation, a process by which multiple ecologically distinct species rapidly evolve from a single ancestor. Birds and many other groups of living organisms greatly benefited from adaptive radiation events in the past. Adaptive radiations feature coincidental multiplication of species numbers and increased morphological disparity in the descendants and they are normally explained by the selection to the new ecological opportunities. Darwin’s finches and close relatives display extreme, in many ways unique variation and evolvability, especially in beak shapes, matched by the diversity of their diets. While much is already known about ecology and history of these birds, the exact causes that generated their diversity are still being investigated. In our work, we combine phylogenetic, morphometric and developmental genetics methods to uncover mechanisms that explain the evolutionary success of this “most singular group of finches”.
Evolution and ecological adaptation as revealed by whole genome sequencing of Darwin’s finches and other species
Speaker: Leif Andersson, Uppsala University (Sweden), Texas A&M University (USA), Swedish University of Agricultural Sciences (Sweden), Princeton University (USA)
Abstract: The Darwin’s finches are a classical example of an adaptive radiation and an iconic model in evolutionary biology. We have now developed a highly contiguous genome assembly for the small tree finch (Camarhynchus parvulus) using long-read Nanopore sequencing combined with HiC analysis. In addition, we have generated extensive Nanopore sequence data from species representing all major types of Darwin’s finches. These data will allow us to explore the importance of genome rearrangements during the rapid evolution of Darwin’s finches as a complement to our previous whole genome sequencing of hundreds of birds using short reads. The Atlantic herring (Clupea harengus) is another iconic model for evolutionary biology. Its merit is a huge population size and minute genetic drift, facilitating studies of the genetic basis of ecological adaptation. Also for this species we have developed a highly contiguous assembly that now facilitates the detection of putative inversions associated with adaptation.