The evolution of human-commensalism in House sparrows

INVITED TALK - WEBINAR IN BIODIVERSITY AND EVOLUTION

House sparrows (Passer domesticus) are a hugely successful anthrodependent species; occurring on nearly every continent and well known by most people. Yet despite their ubiquity and familiarity, surprisingly little is known about how this intriguing and popular species came to be. We sought to investigate the evolutionary origins of the House sparrow and to identify the processes involved in its transition to a human-commensal niche.
We first used whole-genome resequencing of 17 species, covering nearly the entire Passer genus to construct a phylogeny. This suggests Eurasian sparrows (House, Italian and Spanish) diverged and diversified in Northern Africa and the Middle East. Analysis of a resequencing dataset of >250 individuals from across the Eurasian distribution using coalescent modelling confirms that commensal House sparrows most probably arose in the Middle/Near East and then moved westwards into Europe with the spread of agriculture following the Neolithic revolution.
To identify genes and traits involved in adaptation to an anthropocentric niche, we compared phenotypes and genotypes of human-commensal and wild lineages of P. domesticus. 3D analysis of skull morphology suggests more robust skull development and increased brain size in commensal house sparrows. We also identified clear signatures of recent, positive selection in the genome of the commensal house that are absent in wild populations. The strongest selected region encompasses two major candidate genes; COL11A – which regulates craniofacial and skull development and AMY2A which has previously been linked to adaptation to high-starch diets in humans and dogs.
Our work examines human-commensalism in an evolutionary framework, identifies phenotypic traits and genomic regions involved in rapid adaptation and ties their evolution to the development of modern human civilization.

Mark Ravinet is an evolutionary biologist focusing on using genomics to investigate adaptation and speciation. More recently, his interest has shifted to the study of human commensalism and understanding how animals evolve and adapt to thrive in human environments. Mark’s work focuses on using Passer sparrows as a model for this. Mark did his PhD at Queen’s University Belfast on speciation in sticklebacks before going to the National Institute of Genetics, Japan as a JSPS postdoctoral fellow. After this, Mark was a Marie Curie Fellow at the University of Oslo. Mark is now an Assistant Professor at the University of Nottingham, UK. With Glenn-Peter Sætre, he wrote the book ‘Evolutionary Genetics’ (Oxford University Press, 2019).

[Host: Martim Melo, Tropical Biology]