Saturday, February 27, 2016

Sharing Poop and Parasites

I've missed writing to you guys...dissertation and general life has been a little OP lately. (OP = "over powered"'s a slang term used often in the gaming world and I've been married to a gamer for too long to not use it.) I won't waste time saying that this is me starting up regular posts again, the dissertation is still not finished (though I'm getting close!) and I have a pretty busy few months ahead of me. I'm hoping to start back up this summer, after I (FINALLY) graduate, but I'm not making any promises just yet.

Today, I'm writing to you for a different reason. I recently competed in an Elevator Speech Competition hosted by my school. I had a bit of a rough time with delivery, but in the end it wasn't all bad. For this competition, I was given 1 slide (with no moving animations) and three minutes to tell a general audience about my research. For those interested, I've included the slide and a transcript of my speech below. Happy reading!

My Elevator Speech

Poop and parasites; two things that I love despite what other people think. Though not always appropriate dinner conversation, poop provides a wealth of data regarding diet and disease. This is as true for what many of you made earlier today as it was for humans thousands of years ago.

My dissertation focuses on retrieving data from 1,300-year-old paleo-poops known as “coprolites”, like the one in the middle of this slide. By analyzing coprolites, we are able to reconstruct diets and patterns of parasite infections that occurred in pre-history. This allows us to better understand the origins of human-parasite associations that still affect people in the modern world.

The coprolites that I work with come from a cave in Mexico known as “La Cueva de los Muertos Chiquitos”. This cave held hundreds of coprolites that were sealed beneath two adobe floors, making for some of the best-preserved parasite evidence in the world…now that’s the kind of high-quality crap that we archaeoparasitologists dream about!

The diversity of parasites recovered from this site is amazing. Starting at 12 o’clock, we see a Physaloptera egg, which is associated with dogs. Moving clockwise we see a human whipworm egg, then at 4 o’clock we see Toxascaris, another dog parasite that infects humans from time to time. At 6 o’clock are the results of a molecular test used to look for parasites that don’t leave behind eggs. Ignoring the control wells on the top left, every place that you see yellow represents a positive sample for a diarrhea-inducing parasite called Cryptosporidium parvum. Moving along, the egg you see at about 7 o’clock belongs to a tapeworm and the green egg is that of a human pinworm. Finally, the one up there at about 10 o’clock is a fluke egg. Each of these parasites has a distinct life cycle involving different hosts and modes of transmission.

By recovering parasite data, we are able to infer patterns of human behavior, for example, the dog parasites I mentioned tell us that the people using this cave had close associations with dogs and the molecular test at 6 o’clock tells us that lots of people had diarrhea. The pinworm eggs were so prevalent among the coprolites that we know the vast majority of people at this site were infected.
At night, the female pinworm crawls out of the anus to lay her itchy little eggs on the perianal folds, so you know that as soon as the sun set on La Cueva de los Muertos Chiquitos, everyone was either scratching or dealing with diarrhea.  It doesn’t sound like much of a party for them, but it does provide us with lots of information 1,300 years later!

As we continue collecting parasite data from this site, we will gain a picture of the daily lives of people who left no written record, only ancient nuggets of information reflecting what they ate and what was eating them.

No comments:

Post a Comment