Invasive species are nothing new to the Islands of Hawai’i. The first invasive species arrived with, and included, the first Polynesian settlers. Although there does appear to be some evidence that they may have caused the extinction of a few endemic species, the effects of these invasions were most likely relatively minor. Since the first western contact with the islands, the number of invasive species present has skyrocketed, causing a massive ecological disaster. If you want proof of the severity, you need not look any farther than the fact that Hawaii contains well less than 1% of the total land area of the US, but has over a third of the listed endangered species in the US.
At the moment, there is a new invasive species that is making the news here in Hawai’i: a species of “gall wasp” that has been wrecking havoc on trees of the genus Erythrina in Singapore, Taiwan, and a number of other places was found in a valley on Oahu in April. Since then, it has been found in a large number of other places on Oahu, and has started to turn up on other islands, including Maui, and a number of scientists believe that it poses a serious threat to a culturally-significant endemic plant - the Wiliwili (Erythrina sandwichensis). The threat is being taken so seriously that scientists have reportedly begun to bank Wiliwlil seeds as a precaution in case the extant population is completely lost.
So what does this have to do with evolution?