Following his journey to Lord Howe Island to research the evolution of flora on remote oceanic systems, PhD Student Theodore Brook sat down with us to talk about his experiences and what his research is all about.
What is your academic background, and how did you get involved in this project?
I did my undergraduate degree at Cambridge University and then did my master’s at UCL and the Natural History Museum: a real dream come true! My background is broadly in systematics, phylogenetics, and genomics, skills that have come in handy during my PhD. My current project, which is based in the Department of Life Sciences and Kew Gardens, focuses on the evolution of flora on remote oceanic systems, particularly a tiny Australian island in South Pacific. Before my PhD, my work had primarily focused within zoology, so it was very exciting to explore a different kingdom of life. In my project, I combine ecological and genomic data to understand how species evolve in isolated systems.
Why were you interested in going to Lord Howe Island specifically?
My PhD project is focused on the evolution of the flora of Lord Howe Island, a tiny Australian island (less than 16 km2) in the South Pacific Ocean. It is very remote, around 600 km from the mainland. This isolation means that much of the flora (around half) are endemic, meaning they are found nowhere else in the world.
The island provides a natural laboratory to study speciation, the process whereby a species separates into distinct species, in the absence of geographic barriers. This challenges the conventional view held by Charles Darwin and others that geographic barriers, such as mountains and seas, are required for species to become distinct.
How did this opportunity come about?
Previous research from my supervisor Professor Vincent Savolainen and his group has shown that several species, including the world’s most commercially significant palm (genus Howea), have diverged on the island whilst still breeding and exchanging genes with each other. This is the most convincing example of so-called sympatric speciation in nature.
When I noticed the PhD project, which is funded through the Grantham Institute’s SSCP Doctoral Training Programme, I was immediately interested in developing our understanding of this system and determining whether similar processes may be occurring in other groups of plants on Lord Howe.
What were the main goals of your research on the island and how does working on an island like Lord Howe help answer your research questions?
I mostly focus on the genus Coprosma, known as the currant bushes. These plants are found across the Pacific, from Hawai’i to Southeast Asia. Interestingly, Lord Howe Island hosts a staggering five described species, and we currently have a paper in review that describes an additional two new species. This group is a candidate for sympatric speciation, so we are investigating whether this is the case.
Alongside studying Coprosma, I was also provided with the opportunity to start another research project focusing on Gonocarpus, a group of plants known as the raspworts that are found only in Australasia. Through this project, which was funded through the Angela Mawle Seed Fund, I hope to identify a population of Gonocarpus on Lord Howe Island and determine if it is a new species by comparing it molecularly and morphologically to its mainland relatives.
What was a typical day like in the field? Were there any moments of surprise, discovery, or difficulty during the trip?
I have been lucky enough to go to Lord Howe Island three times, with a slightly different objective each time. A typical day in the field would start the evening before with planning the field site for the next day. After packing my bag with materials for sampling, I then head out early on my push bike, the primary mode of transport on Lord Howe, to the start of the hike. I then track down the population of plants I am aiming to sample.
Most of the species I study are high-elevation rainforest species, so this would usually involve a substantial hike to the field site. Once at the site, my colleagues and myself collect plant material for genetic samples alongside ecological data and more material for dried herbarium specimens,
During my last trip I even had the opportunity to camp in the cloud forest at the top of one of the mountains in the south of the island, as we were aiming to collect rare plants from one of the most remote areas of the island.
How did working with international collaborators influence your research or perspective?
Working with international collaborators has been hugely beneficial for my PhD project and my professional development more generally. We work closely with Ian Hutton, a world-renowned naturalist who lives on Lord Howe Island, who has an intimate knowledge of the flora of the island. Without him, it would be impossible to properly understand the distribution of species and habitats across the island.
I was also fortunate enough to spend four months working with colleagues at the Botanic Gardens of Sydney. I primarily worked with Dr Trevor Wilson, a Systematic Botanist at the National Herbarium of New South Wales. Trevor is an exceptional botanist who not only helped develop my PhD project but also taught me invaluable skills, such as plant identification, field skills, and herbarium management, that will help my professional development as a botanist.
I also started an exciting project with Dr Karen Sommerville and Mel O’Donovan at the Australian PlantBank to study the seed biology of Coprosma seeds, such that they can be stored and germinated outside of their home environment. I want to extend a huge thank you to all the team at Botanic Gardens of Sydney for hosting me and supporting my project, it was a brilliant experience!
What was the most memorable part of your experience on Lord Howe?
The most memorable part of my fieldwork was the moment I landed for the first time on Lord Howe. The two-hour flight from Sydney is entirely over the ocean, on a tiny and somewhat scary plane, until this tiny bit of rock with two mountains and a brilliant blue lagoon sticks out from the water. As someone interested in botany and the natural world more generally, this was utterly surreal and a real ‘pinch-me’ moment.
Thank you for sharing this wonderful and inspiring experience!