Research InterestsI am interested in how biological diversity evolves and is maintained. I am currently focusing on two main questions:
1. To what extent does local adaptation play a role in speciation?The
differentiation of populations into distinct species can be the result
of local adaptation pushing populations apart, can be due to drift and other neutral
evolutionary processes, or most likely, a combination of both. I am trying to understand which evolutionary forces
are responsible for the diversifications of the white proteas in South
Africa. The white proteas are a small subgenus (6 species)
within the genus Protea,
which are endemic to the Cape Floristic Region in southwestern South
Africa. The environments in which they live vary in water and
availability so I am investigating the degree to which differentiation
in traits associated with their use has been associated with speciation
events. I am doing this by comparing patterns of variation in
genetic markers with variation in water and nutrient related
traits. I will then relate these to soil and climate
characteristics of their home
2. Community assembly of the Cape floraI became interested in the questions of how communities are assembled through a side project on Pelargonium,
a diverse genus in the Cape Floristic region. Pelargoniums vary
in many ways, including leaf morphology and floral morphology, but most spectacularly in their body plans. They range from
shrubs, to subshrubs, to stem succulents to acaulescent geophytes.
They can live in close proximity to each other, sometimes within
inches. I am interested in exploring how it is that pelargoniums
can share space. Do they tend to be found near closely
related species, or more distantly related species? I, together
with collaborators, am investigating this question at two scales.
The first is at the scale of the individual. How far from
each individual do we find their nearest conspecific pelargonium?
How far from each individual do we find their nearest
heterospecific pelargonium? The second scale is across western
South Africa. We will explain the degree to which the
co-occurrence of species is explained by genetic distance and
morphological differences between the species. We will then be
able to address the question of how community assembly processes differ
at different scales.
I am also interested in exploring similar questions within the genus Protea. The presence or absence of every protea species at 60, 000 locations in South Africa has been mapped in the Protea Atlas Project.
These data will allow us to very throughly investigate the
relative importance of different community assembly processes, such as
selection and competition, at a wide variety of scales, ranging from 1/4
degree radius plots to larger landscape scales.