All About eDNA

If you're a biology student, you've likely discussed the myriad of genetic materials involved in the life cycles of countless types of organisms. mRNA, tRNA, nuclear DNA, mitochondrial DNA are just some of the many kinds of ribonucleic acid that help the world go around, however, one that is likely unfamiliar is eDNA. eDNA, or environmental DNA, is a term used to describe DNA found outside of an organism in an ecosystem. As animals shed, secrete fluids, excrete, and other body functions they almost leave behind a footprint of themselves in the form of eDNA. By collecting this eDNA from the environment, scientists can deduce a variety things about the environment it was collected in. 

An example of how eDNA is collected and used 

Previously, the only way to take count of the number of members of a species in an environment were methods like camera traps and field surveying, but eDNA provides a new method which doesn't require a physical sighting of the animal. Scientists use a complex methods of sample collection and analysis in order to deduce what animals might have been to a given locations. This is most helpful in dense or hard to reach environments like deep rainforests where relying on spotting is difficult and unreliable. eDNA sample collection can quickly provide a wealth of data about these locations, saving time, money and potentially lives. eDNA sampling cannot replace physical spotting yet, but it is nonetheless promising as a future avenue for studying environments. 

Sources: 

https://www.conservation.org/blog/what-on-earth-is-edna

https://www.nature.com/articles/s44358-025-00044-x