We are recruiting a highly motivated student to undertake PhD studies into the systematics and biogeography of dioecy in the Hawaiian radiation of flowering plants within the genus Wikstroemia, based at the dynamic and collegial Biology Department at Lund University, Sweden. Background: This is the second of 2 PhD positions funded by an ERC starting grant to the principal investigator. The major goal of this research is to understand the genomic changes underlying a critical evolutionary transition in eukaryotic life: the evolution of separate sexes (dioecy) from hermaphroditism via the origin of new sex chromosomes. This work will shed light on how new sex-determining genes and sex-linked genome regions evolve by studying repeated evolutionary transitions from hermaphroditism to dioecy within the endemic Hawaiian radiation of the flowering plant genus Wikstroemia (Thymelaeaceae; ¡­12 spp.). The Hawaiian Wikstroemia are particularly interesting in this respect because they have evolved at least two, and possibly three, different genetic mechanisms of sex-determination in parallel during what appears to be a recent island radiation. Note: the start date for this position was originally planned for later in 2024 (as mentioned in an earlier evoldir announcement), but has been moved forward to March/April. ---- PhD opportunity: "Molecular systematics of Hawaiian Wikstroemia and the biogeography of sex-determining genes" Anticipated start date: March 2024 The goal of this PhD project is to provide the macroevolutionary context for understanding the evolution of dioecy in the Hawaiian Wikstroemia by clarifying both the systematics of the Hawaiian clade within the genus, and the biogeography of sex-linked genome regions and sex-determining genes within the Hawaiian radiation. The major aims of the project are to (i) clarify the phylogenetic relationships among extant Wikstroemia species, including estimating the timing of colonization of the Hawaiian archipelago by a hermaphrodite ancestor, and placing the Hawaiian clade within the broader genus-level phylogeny; (ii) perform a phylogenomic and biogeographic analysis of sex-linked genome regions for each form of dioecy, with the aim of reconstructing the origin and evolution of the different sex-linked genome regions both by a formal historical biogeographical analysis, and also (iii) by studying congruence/discordance between the species tree for the Hawaiian radiation-level phylogeny and gene trees for coding sequences within the sex-linked genome region for each form of dioecy. The Hawaiian Wikstroemia have a fascinating evolutionary history, with many possible directions for related systematic and biogeographic questions, depending on the interests of the student. The project may include field work in Hawai¡¯i, but will also involve extensive use of herbaria collections and 'museomics', and is suitable for candidates with a background and an interest in phylogenetics, molecular systematics, biogeography, evolutionary biology of flowering plants, and botany. APPLY HERE: https://lu.varbi.com/en/what:job/jobID:693839/ (reference #PA2024/183). The position should also be listed at https://www.lunduniversity.lu.se/vacancies. For more information, please see the project description at https://colinolito.com/opportunities/, or send me an email. Successful applicants will have a track-record demonstrating a passion for evolutionary biology, genetics, systematics, and/or botany. Suitable applicants must meet the general admission requirements for third-cycle courses and study programmes (i.e., the international equivalent of B.Sc., with honors research experience) in a discipline relevant to the PhD project. Applicants with additional relevant experience and/or a M.Sc degree are strongly encouraged to apply. The Olito Lab is part of the Genetics of Sex Differences Research Group (https://portal.research.lu.se/en/organisations/genetics-of-sex-differences) within the dynamic and highly collegial Biology Department at Lund University. The SexGen research group is a welcoming and highly collaborative group of PI's, post-docs, and students from the labs of Dr. Jessica Abbott, Dr. Bengt Hansson, and Dr. Colin Olito. Colin Olito, Biology Department, Lund University email: colin.olito at biol.lu.se Lab website: https://colinolito.com/ Colin Olito (to subscribe/unsubscribe the EvolDir send mail to golding@mcmaster.ca)