What is a characteristic of sympatric speciation?

The correct answer highlights that sympatric speciation occurs when new species arise within the same geographic area as the original population. This form of speciation does not rely on physical barriers that separate populations, as seen in allopatric speciation. Instead, it often involves mechanisms such as behavioral changes, temporal isolation, or polyploidy, particularly in plants, where a population may diverge into different reproductive groups even while living in the same location. This can lead to reproductive isolation, facilitating the emergence of new species without geographical separation.

The other options focus on different mechanisms or conditions for speciation, such as physical barriers that define allopatric speciation or the requirement of mass extinctions which are not necessary for sympatric speciation to occur. They also suggest that genetic mutations alone can lead to new species, which may be a part of the process but does not encompass the full spectrum of sympatric speciation.