Dr Nathan Lo1

1The University of Sydney, Australia

Biography:

I am interested in genome evolution, molecular ecology, and phylogenetics of insects and other arthropods. After joining the School of Life and Environmental Sciences at The University of Sydney in 2009, I was an ARC QEII Research Fellow from 2010-2014, and then ARC Future Fellow (2017-2021). I was Biodiversity Research Initiative Leader at the Australian Museum, Sydney from 2008-2009, and an ARC Australian Postdoctoral Fellow at the University of Sydney from 2004-2007. I also held postdoctoral fellowships at the University of Milan, Italy (2003-2004) and the National Institute of Agrobiological Sciences (Tsukuba, Japan; 2001-2003). I have published over 170 scientific papers, which have been cited over 11000 times.

Abstract:

The genetic changes that enabled the evolution of eusociality have long captivated biologists. In recent years, attention has focussed on the consequences of eusociality on genome evolution. Studies have reported higher molecular evolutionary rates in eusocial hymenopteran insects compared with their solitary relatives. To investigate the genomic consequences of eusociality in termites, we sequenced genomes from three of their non-eusocial cockroach relatives. Using a phylogenomic approach, we found that termite genomes experienced lower rates of synonymous mutations than those of cockroaches, possibly as a result of longer generation times. We identified higher rates of nonsynonymous mutations in termite genomes than in cockroach genomes and identified pervasive relaxed selection in the former (24–31% of the genes analysed) compared with the latter (2–4%). We infer that this is due to a reduction in effective population size, rather than gene-specific effects (e.g., indirect selection of caste-biased genes). We found no obvious signature of increased genetic load in termites, and postulate efficient purging at the colony level. Our results provide insights into the evolution of termites and the genomic consequences of eusociality more broadly.