Evolution of the mammalian baculum

Researching the most evolutionary divergent bone in the mammalian body

Some mammals have a morphologically elaborate baculum, while other species lack the bone altogether.

Consistent with studies of the evolution of insect genitalia (Simmons, 2014), recent work from our lab has demonstrated that sexual selection is responsible for the evolutionary divergence of baculum morphology among populations of house mice (Simmons and Firman, 2014), although the mechanisms involved are unknown.

We will now use a cross-disciplinary approach to explore the selective mechanisms acting on the mammalian baculum.

The effects of baculum morphology on changes in female reproductive hormone profiles, pregnancy initiation, and embryo development will be examined using the house mouse model.

Quantitative genetic approaches will explore genetic variation in baculum morphology and correlated endocrine responses to stimulation during copulation among females, while comparative studies among species of mammal generally will examine macroevolutionary changes in baculum complexity in response to the strength of sexual selection.

The project thereby aims to provide a comprehensive view of the proximate mechanisms of selection and its ultimate consequences for evolutionary divergence of this bone.

For more background information, see the suggested readings below.

Research team leader: Professor Leigh Simmons

I currently hold two ARC Discovery Project grants that fund research into sperm competition and the evolution of multiple mating by females using insects, mice and frogs as model systems. I am also engaged in research on sexual selection on humans. Collectively, these research programs seek to determine the direction and strength of selection acting on male and female reproductive strategies, and on the morphological and life history traits that contribute to fitness, from the whole organism to its gametes. Visit the UWA Research Repository to view my academic profile.

How to apply

Interested in becoming part of this project? Complete the following steps to submit your expression of interest:

Step 1 - Check criteria

General UWA PhD entrance requirements can be found on the Future Students website.

Step 2 - Submit enquiry to research team leader

Step 3 - Lodge application

After you have discussed your project with the research team leader, you should be in a position to proceed to the next step of the UWA application process: Lodge an applicationDifferent application procedures apply to domestic and international students.


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