Evolutionary Medicine and Anatomy Research


I became interested in evolutionary medicine during the last few years of my Bachelor's degree at Case Western Reserve University. This new field combined two of my favorite academic interests: human origins and human health. As I began teaching anatomy, I found that embryology could not cover all of the "why?" questions my students were asking. For some students, evolution provided a framework for them to organize anatomical knowledge. For this reason and my own interests, I have continued to examine human anatomy and health in evolutionary terms.

Syphilis and Transplacental Infection

My first project in Evolutionary Medicine was my Senior Capstone project, an investigation into the evolutionary history of syphilis and how it gained its ability to cross the placental barrier.

Venereal and congenital syphilis are historic and contemporary health problems throughout the world. This is due to the evolution of a highly invasive pathogen that exploits the immunoprotective niches within the human body. The invasive nature of this pathogen is emphasized by its unique ability to transplacentally infect a fetus. This project explores the hypothesis that the evolution of this pathogen towards invasiveness is a response to a change in host ecology out of the tropics into cold and dry environments during human migration. The colder and drier the host’s physical environment became, the greater the selection pressure for more invasive pathogens. This led to the evolution of the highly invasive and highly host dependent pathogen we see today.


Finding Cranial Nerve XI 

As I finished my Master's degree, I began applying evolutionary theory to better understand anatomical and medical quirks of the human body. Cranial nerve XI was the first target of this exploration. The article describing these findings was published in The HAPS Educator in 2017.


Twitter, Evolution, Human Anatomy, and Tinbergen: A Class Case Study

In Spring 2019, I was able to incorporate my evolutionary training and anatomical knowledge into an upper-level course for undergraduate Medical Sciences students. This project is described in the poster below.


Baculum and Erectile Dysfunction

In the Summer of 2018, I was lucky to meet Dr. Laura Hechtel at the Evolutionary Medicine Summer Institute (EMSI; https://sites.duke.edu/emsi/) where we began exploring how the baculum was lost in humans. We published this exploration in the journal of Evolution, Medicine and Public Health in 2019:

Erectile dysfunction and the baculum 
Theodore C Smith, Laura Hechtel
Evolution, Medicine, and Public Health, Volume 2019, Issue 1, 2019, Pages 147–148, https://doi.org/10.1093/emph/eoz023