<span>H. floresiensis tended to be smaller than H. sapiens. In addition, they had much smaller heads and, therefore, smaller brains. Also, the species had a much more sloped forehead, shoulders that were more forward-leaning, and feet that were relatively large for their small body size.</span>
The correct answer is speciation.
Speciation is the term that describes the evolutionary process causing populations to evolve into different species. There are four different types of speciation: allopatric, peripatric, parapatric and sympatric. In this case, the process described is an allopatric speciation, the most common of these four types. Allopatric speciation happens when populations are geographically separated, an event that obstructs the gene flow. Since the gene flow stops, the populations evolve in response to the different environments that they live in.