My research focuses upon the evolution, biogeography, and systematics of the angiosperm order Apiales, which includes the well-known families Apiaceae, Araliaceae and Pittosporaceae. Evolutionary relationships within Apiales have been difficult to resolve due to large amounts of parallel and convergent evolution of morphological characters (presumably due to repeated migrations of Southern Hemisphere and tropical lineages into the north-temperate zones). This problem is compounded by difficulties at almost every taxonomic level, from species circumscriptions to the placement of this order among the higher dicots. Molecular phylogenies, primarily using DNA sequence data from chloroplast and nuclear regions, have given us a solid ordinal framework, enabling us to examine evolutionary patterns more closely. Importantly, it will allow us to critically examine morphological characters, from gross morphology to embryogeny.

My research will continue the ordinal-level work on Apiales, but will focus on the polyphyletic (unnatural) apioid subfamily Hydrocotyloideae. This subfamily was considered intermediate, or a “bridging group,” between Araliaceae (more primitive) and Apiaceae (more advanced), so it was the focus of many evolutionary studies and theories for the entire order. Our recent work suggests that the hydrocotyloids are spread between four distinct lineages. Since the hydrocotyloids were envisioned as a bridging group between Apiaceae and Araliaceae, many evolutionary assumptions about these families were based morphological studies involving this group. Our findings question many of these assumptions about apioid evolution, and our work is now focusing on individual hydrocotyloid lineages so that we can begin to untangle the complex web of apialean evolution. Hydrocotyloids occur primarily in Australia, southern Africa and South America. Field studies are important in biology, and systematics is no exception. We aim to collect more material in these regions, which will not only provide physical material for our studies, but provide the collectors with information about the group that cannot be gained by looking at an herbarium sheet. Morphological studies will parallel our molecular focus on the hydrocotyloids, and across Apiales, including electron microscopy and embryology.

I am also entering into studies of polyploid evolution (genome duplication) in Asteraceae, the second most diverse family of flowering plants, by examining the genus Antennaria, which has several large, polyploid agamic complexes. The Antennaria rosea complex grows in Rocky Mountains of North America contain (and possibly in the Andes of South America), and is an excellent model system for studying polyploid evolution, as so much background information available, including morphological, allozyme, ecological, and molecular data. This work is being conducted in close collaboration with Dr. Randall Bayer, the leading expert on Antennaria.

I maintain close collaborative research with colleagues both within the U.S. and abroad, including Argentina, Australia, Britain, France, New Zealand and South Africa. Collaborations are important not only for fostering communication among workers, as they provide a means for the exchange of material and field support.

My past research involved studies on Australian legumes (Fabaceae), producing phylogenies and monographs for several genera, particularly the large and complex genera found in the botanically diverse regions of southwest Australia. I am also involved in a collaborative project on the Pittosporaceae that involves workers in the US, Australia, Britain, and New Zealand. Click here to view my laboratory poster (pdf).

Chandler, G. T., and G. M. Plunkett. 2004. Evolution in Apiales: nuclear and chloroplast markers together in (almost) perfect harmony. Botanical Journal of the Linnean Society 143: 123-147.

Chandler, G. T., R. J. Bayer, and S. R. Gilmore (2004). The Oxylobium/Gastrolobium (Fabaceae: Mirbelieae) conundrum: further studies using molecular data, and a reappraisal of morphological characters. Plant Species Biology 18.

Chandler, G. T., M. D. Crisp, L. W. Cayzer, and R. J. Bayer. 2002. Monograph of Gastrolobium (Fabaceae: Mirbelieae). Australian Systematic Botany 15: 619-739.

Chandler, G.T., R. J. Bayer, and M. D. Crisp. 2001. A molecular phylogeny of the Australian genus Gastrolobium (Fabaceae: Mirbelieae) and allied genera using chloroplast and nuclear markers. American Journal of Botany 88: 1675-1687.

Chandler, G. T., and R. J. Bayer. 2000. Phylogenetic placement of the enigmatic Australian genus Emblingia based on rbcL sequences. Plant Species Biology 15: 67-72.