Why does this recent discovery about the Galapagos finches prove that it's often challenging for scientists to determine when two groups of individuals are separate species? What factors do scientists need to consider when determining whether a species is a new species or part of an existing species?

The smokey mountains have over 2,100 miles of rushing mountain streams and rivers that flow through the park. in each mile lives a diverse community of native fish, amphibians, insects, and larvae, some of which are found only in the southern appalachians. park managers and scientific researchers test many factors such as fish populations, the watersheds and water tests to determine a) too many lizards are present b) the water quality of the stream c) rainwater is running into local streams d) if visitors to the park are overstaying their welcome