Coevolution: Native and Invasive Plants

Reported in June 2012, the University of Georgia conducted a study in which it found that invasive species (kudzu, privet, and garlic mustard) and native plants (Clearwater plant) are currently undergoing co-evolution. Prior to this research, scientists believed that the native plants were unable to combat the invasive plants, which were introduced from Europe during the mid-1800’s. Yet, the study gave the first evidence to show that the native plants possibly evolved resistance to the garlic mustard plants. Yet, this is a prime example of co-evolution because the invasive plants are fighting back.

            When the invasive plants were introduced in the 1800’s, they quickly spread from New York, Virginia, and Chicago to the Northeast, Southeast, and the Midwest. They are able to survive by fighting with a compound called Sinigrin. This compound kills the fungi that helps native plants get nutrients from the soil. It is so effective because Sinigrin is new to North America. It is able to kill the native plants because these plants did not have a resistance to the compound. In addition, the invasive plants are able to survive because even after they are removed, they grow back after a year as forest undergrowth.

            Richard Lankau, who works at the university, has found evidence that the native plants have evolved because of the invader plants. He took a native Clearwater plant called Pilea pumila and found that it has higher resistance to Sinigrin. This shows that since this plant is in the same habitat as the garlic mustard, co-evolution has occurred. To explain further, he was able to get to this information because he found that the garlic mustard (the invasive plant investigated in his experiment) produced more Sinigrin in areas with more native plants.

            Lankau also found that the native plants were more successful at surviving when the garlic mustard was present. To figure this out, he took the native plants back to their origin location that did not have garlic mustard. The native plants that had already created a resistance did not survive as long without the garlic mustard present as the native plants that were not resistant when exposed with the garlic mustard. "It's not all good for those populations that are evolving tolerance because they are less successful in the absence of garlic mustard, their resistance to the invasive species comes at a cost” (Lankau 1).

            To conclude, the native and invasive plants are currently undergoing co-evolution and it is believed that at one point in time in the far future they may be able to coexist with each other.

Garlic Mustard

Pilea pumila

Fahmy, Sam (2012, June). Study Provides First Evidence of Coevolution between Invasive, Native Species. Retrieved October 19, 2014 from UGA Today.