profile thumbCan sexual selection improve population fitness?


For an overview of how sexual selection can improve the mean fitness of populations, check out my blog on the Evolution Letters Editors’ blog – Does sexual selection help or hinder population performance?

Sexual selection is often considered to work in opposition to natural selection due to the cost of maintaining sexually-selected signals. However, genic capture theory states that mating success, especially in the face of competition, is ultimately determined by condition, and therefore shaped by a large number of naturally selected genes.



Sexual selection may therefore augment natural selection by improving the purging of deleterious mutations and the fixation of beneficial ones, creating population-level fitness benefits.




I test this idea using experimentally evolved populations of the promiscuous flour beetle, Tribolium castaneum, which differ only in their contrasting opportunities for male-male competition and female choice across 50-100 generations of selection.


Godwin, J.L., Spurgin L.G., Michalczyk, L., Martin, O.Y., Lumley, A.J., Chapman T.C. & Gage, M.J.G. (2018).  Lineages evolved under stronger sexual selection show superior ability to invade conspecific competitor populationsEvolution Letters (early view).

Godwin, J.L., Vasudeva, R., Michalczyk, L., Martin, O.Y., Lumley, A.J., Chapman T.C. & Gage, M.J.G. (2017). Sperm competition intensity selects for longer, more costly sperm. Evolution Letters, 1,  102-113.

Godwin, J.L. (2016). Consequences of sexual selection for reproductive and life history traits in Tribolium castaneum.
ZSL Thomas Henry Huxley Award and Marsh Prize – commendation

Lumley, A.J., Michalczyk, L., Kitson, J.J.N., Spurgin, L.G., Morrison, C.A., Godwin, J.L., Dickinson, M.E., Martin, O.Y., Emerson, B.C., Chapman T.C. & Gage, M.J.G. (2015). Sexual selection protects against extinction. Nature 522, 470-473.


Presentations, Posters & Outreach:

Association for the Study of Animal Behaviour Winter 2017 – Sexual selection: Do we still need to test the alternatives? 
Talk title: Does sexual selection improve population fitness?

European Society for Evolutionary Biology XVI Congress 2017eseb_logo – Groningen, The Netherlands
Talk title: Does sexual selection improve population fitness?

Soapbox Science 2017 – ‘Sex-ual Selection in the City’

“If a flour beetle egg was the size of a rugby ball how long would a sperm cell be?”

Read more about my experience and reasons for getting involved on the UEA BIO Equality and Diversity blog: Soapbox Science: shouting for women in STEMM


Annual UEA Centre for Ecology, Evolution & Conservation ‘Rebellion’ conference 2017uea-ceec-jpg
Talk title: Does sexual selection improve population fitness?


UCL, Centre for Ecology & Evolution Summer Symposium 2016 – War & Peace – the dynamics of evolutionary conflict
Poster title: Sexual selection increases sperm competitiveness and sperm length – silver poster prize

Take a look at the UEA CEEC science news and events blog for a simple summary of my paper about sperm competition and sperm length evolution ‘Sperm size matters’.


UEA Centre for Ecology Evolution & Conservation ‘Rebellion’ 2016 Talk title: Sperm competition selects for directional not stabilising selection on sperm length best student talk prize


Association for the Study of Animal Behaviour Easter Meeting 2015 and
UEA Centre for Ecology Evolution & Conservation ‘Rebellion’ 2015
Talk title: How does sexual selection shape sperm competitiveness and ability to invade new populations?



Career History: 
  • Postdoc, University of East Anglia (2016-Present)
  • PhD Evolutionary Biology, University of East Anglia (2016)
  • Senior Education Officer, Norfolk Wildlife Trust (2011-12)
  • Teacher of Science, Sprowston High School, Norwich (2010-2011)
  • MSc Ecology & Conservation, University of East Anglia (2010)
  • Field Studies Teacher, Holt Hall Field Studies Centre (2006-09)
  • Teacher of Science, Abbeyfield School, Chippenham (2005-06)
  • PGCE Secondary Science, University of Bath (2004)
  • BSc Biology, University of Bath (2003)
Contact – | @joannelgodwin