Dr Bonnie Fraser

About me: The main goal of our research group is to investigate how populations adapt to their local environment. How populations adapt to local environments is not only a fundamental question in evolutionary biology but one that has implications for the conservation of species in our rapidly changing world. We explore local adaptation using an interdisciplinary approach that combines population genomics, quantitative genetics, behavioural ecology, and experimental evolution.

Interests:

How repeatable is evolution?
Convergent evolution, where independent lineages evolve similar phenotypes in response to similar challenges, can provide valuable insight into how selection operates and the limitations it encounters. It can also provide a framework for predicting evolution to future challenges. Our research takes a population genomics approach to understand how convergent evolution operates at the genomic level coupled with quantitative genetics to understand the genetic architecture of known convergently evolving traits. 
 
How do populations adapt to new environments?
The early phases of adaptation may be the most important, as it will determine whether a population will persist in its new environment. This time is also coupled with small founding populations, adding to the challenges faced by populations in new environments. Our work has taken a temporal genomics and experimental evolution approach to this question, where we have sampled genomic data over multiple time points in experimental populations to examine the dynamics of early adaptation.  
 
What maintains variation in natural populations?
Populations harbour enormous diversity in important and we still do not fully understand why. Recent genome sequence analysis suggests that ‘balancing selection’ plays a major role in maintaining genetic diversity and negative frequency-dependent selection (NFDS) might be the most powerful and prevalent. NFDS occurs when fitness of a particular genetic type increases as its frequency within a population decreases. Our work examines the genomic signatures of balancing selection in natural populations. We are also developing experimental evolution systems to directly map the drivers of NFDS to the genome. 

Research Systems
Our research primarily uses the model evolutionary and ecological system the Trinidadian guppy. Guppies in the Northern Mountain Range of Trinidad offer a natural laboratory for studying evolutionary change and the genetics of adaptation. Waterfalls separate the rivers the guppies call home into downstream stretches, which contain many predators, and upstream stretches, where the guppies live relatively free of predation. In response to this naturally replicated environmental gradient, guppies from low predation sites have evolved to be larger and more colourful, and to display less anti-predator behaviour. They are also subject to a series of in situ translocation studies, making studying rapid evolution tractable.

We are developing these questions and research areas in new systems, from fisheries to invasive species (watch this space!).

Postgraduate Research opportunities:  I am open to email enquires from students with their own funding interested in pursuing an MSc by Research or PhD in evolutionary biology research. I am also open to supporting students interested in this are who would like to apply to the China Scholarship Council, Commonwealth Scholarship, or other PhD funding scheme.