DNA from Droppings

Part of the Ecology Disrupted Curriculum Collection.

A close-up of a man’s open hand held a few inches above dry rocky soil, holding Bighorn sheep droppings, seen as five small brown pellets.


Download the files below to use offline, or to incorporate into your own lesson planning tools.

DNA from Droppings teacher's guide



This discussion explores why Dr. Epps collected droppings from all over the bighorn sheep range.


Key Idea: Dr. Epps collected DNA from bighorn sheep droppings to compare genetic similarity amongst different populations.

Question: Why did Clinton Epps collect droppings from all over the bighorn sheep range? How did these droppings help Dr. Epps test his hypothesis that highways block mating between sheep populations from different mountaintops?

Answer: These droppings allowed Dr. Epps to see if the highways isolated bighorn shee populations. He was able to compare DNA from populations that were not separated by highways with populations that were separated by highways. 

Note: Emphasize that sheep droppings are a good source of DNA for testing. You can discuss with your students sources of DNA for forensic testing in people.