The R.A. Fisher Prize

 The winner of this year’s R. A. Fisher Prize is Megan Greischar, for her paper “Predicting optimal transmission investment in malaria parasites.” Evolution (2016) 70:1542-1558.

In this study, Dr. Greischar examined the growth-reproduction tradeoff faced by malaria parasites, which must allocate resources to within-host proliferation as well as the production of specialized life stages for onward transmission. The way parasites balance this tradeoff influences exploitation of host resources---and hence virulence---and the rate of disease spread through host populations. She built a within-host model to examine the conflicting selection pressures and identify the optimal allocation to transmission. She developed novel computational methods to consider a wide range of potential strategies, using splines to describe plastic allocation with few parameters. The model suggested that parasites benefit from delaying transmission stage production, just as macroorganisms can benefit from delayed reproductive effort. Innate immunity and coinfecting parasites imposed strong selection favoring parasites that invest disproportionately in proliferation rather than transmission (“reproductive restraint''), resulting in more rapid and extreme exploitation of host resources. Selection on transmission investment therefore represents one mechanism by which enhanced virulence could be adaptive for parasites. More generally, the approach can accommodate highly complex strategies within richly detailed ecological models, providing a much-needed alternative to analytical methods that could be adapted to diverse organisms.

About the R. A. Fisher Prize

R. A. Fisher Prize

The R. A. Fisher Prize is awarded annually by the Society for the Study of Evolution for an outstanding Ph.D. dissertation paper published in the journal Evolution during a given calendar year.

This prize pays tribute to one of the most distinguished evolutionists of the 20th Century, Sir Ronald Fisher, who with JBS Haldane and Sewall Wright, developed theoretical population genetics and established its central position within evolutionary biology.  Fisher’s interests ranged widely, but placed particular emphasis on the dynamics of mutation and selection and how these contribute to adaptation.


2016 Application Information

The R. A. Fisher Prize is awarded annually by the Society for the Study of Evolution for an outstanding Ph.D. dissertation paper published in the journal Evolution during a given calendar year. The award comes with a $1000 honorarium.
Eligibility -- To be eligible for consideration, a manuscript must be based on graduate work of the primary author.
Nominations/Application -- Authors of eligible manuscripts may initiate a nomination upon acceptance of their manuscripts for publication. Nominations must include the final version of the manuscript, dissertation completion date, and a supporting letter from the Ph.D. supervisor or other individual familiar with the candidate and their work. The supporting letter should indicate the candidate’s role in completing the research and writing the paper (if the candidate is not sole author), should place the work in the larger context of the field (novelty, importance), and should discuss the overall quality of the student's research.

Nominations for manuscripts published in 2016, Volume 70, will be accepted throughout the year but must arrive no later than January 31, 2017. The complete nomination should be submitted electronically to the SSE Secretary (Cynthia Weinig) at

Award -- The Fisher Prize is accompanied by a check for U.S. $1000, and will be awarded at the annual meeting of the Society for the Study of Evolution. The recipient is invited to attend the annual meeting to receive the award. To facilitate attendance, the SSE provides funds to cover the costs of conference registration, accommodation during the conference, and expenses for travel to and from the conference. The recipient will be notified of the award by late March 2017.


Past Fisher Prize Winners

2016 Jennifer Lohr (more info)
2015 Alison E. Wright (more info)
2014 Amy Hurford (more info)
2013 William Soto
2012 David McCandlish
2011 D. Luke Mahler
2010 Britt Koskella
2009 Megan Higgie
2008 R. Brian Langerhans
2007 Guillaume Martin
2006 Maurine Neiman



Dr. Alison E. WrightThe 2016 Fisher Prize was awarded to Dr. Jennifer N. Lohr, for her paper: Lohr, J. N., and C. R. Haag. 2015. Genetic load, inbreeding depression, and hybrid vigor covary with population size: An empirical evaluation of theoretical predictions. Evolution 69:3109-3122.

In this paper, Lohr and Haag test predictions from population genetic theory on the genetic consequences of small population size, a fundamental question in evolutionary biology. Lohr used eight natural populations of Daphnia magna that varied in effective population size, along with carefully designed crosses within and among populations, to test these predictions. She showed that Ne accurately predicted inbreeding depression, genetic load, and hybrid vigor, strongly supporting theoretical predictions based on recurrent mutation to unconditionally deleterious alleles. These results have important implications for evolutionary processes in natural populations, including for the evolution of dispersal, breeding systems, local adaptation, and aging.

Dr. Lohr received her PhD in 2015 from the Department of Biology at the University of Fribourg, with Christopher Haag. She is now a Postdoctoral Research Associate at the University of Hamburg with Susanne Dobler.


Dr. Alison E. Wright

The 2015 Fisher Prize was awarded to Dr. Alison E. Wright, for her paper: Alison E. Wright, Peter W. Harrison, Stephen H. Montgomery, Marie A. Pointer and Judith E. Mank. 2014. Independent stratum formation on the avian sex chromosomes reveals inter-chromosomal gene conversion and predominance of purifying selection on the W chromosome. Evolution. 68(11):3281–3295.

In this paper, Wright and co-authors used a comparative approach across a monophyletic clade of birds, spanning 90 million years, to study the mode, mechanism and rate of divergence between the avian Z and W sex chromosomes. This work, based on the largest cross-species dataset of Z-W orthologs to date, revealed the complex recombinational history of the avian sex chromosomes. The results show that although birds share the same sex chromosome system, recombination between the sex chromosomes has been suppressed independently multiple times, allowing for convergent patterns of divergence. Wright and her co-authors also found that recombination and gene conversion persist on sex chromosomes over both long and short evolutionary trajectories. Importantly, the study shows that the female-limited and degenerated W chromosome is evolving with a significant contribution of purifying selection, indicating that the remaining W-linked genes play an important role in female-specific fitness.

Dr Wright received her PhD in 2014 from the Department of Zoology at the University of Oxford, with Judith Mank. She is now a Postdoctoral Research Associate at University College London.





The 2014 Fisher Prize was awarded to Dr. Amy Hurford for her paper: Hurford, A. and T. Day. 2013. Immune evasion and the evolution of molecular mimicry in parasites. Evolution 67(10): 2889-2904. Amy Hurford

Hurford explored a variety of hypotheses about the coevolution of vertebrate immune systems and pathogens, using mathematical models. One of her primary goals was to understand the evolutionary origins of infection-induced autoimmune disorders. She developed mathematical models using techniques from dynamical systems and game theory to better understand the conditions under which we might expect pathogens to evolve molecular mimicry. She and her coauthor analyzed the patterns of molecular mimicry that are expected under two hypotheses regarding molecular mimicry by parasites. One of their findings was that the highest risk of autoimmunity comes from parasites that display intermediate levels of mimicry. Interestingly, and highly relevantly, they also explored the consequences of different medical interventions on the evolution of mimicry and the incidence of autoimmunity.

Dr. Hurford received her Ph.D. in 2011 from the Department of Mathematics and Statistics at Queens University, where he was advised by Dr. Troy Day. Following postdoctoral appointments at York University and the University of Toronto, she began a faculty position at Memorial University of Newfoundland.


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