Question

A new species evolves in an extensively interbreeding population as individuals with one phenotype choose to mate only with individuals much like themselves. What has happened in this population?

O allopatric speciation
O sympatric speciation
O parapatric speciation
O reinforcement

Answer 1

Sympatric speciation is taking place when individuals within a population preferentially mate with similar phenotypes without geographical separation, leading to the evolution of a new species within the same habitat.

Step-by-step explanation:

In the described scenario, individuals within a single population are choosing to mate with those that are phenotypically similar to themselves without any geographic separation. Therefore, the process occurring in this population is sympatric speciation. Unlike allopatric speciation, where species evolve due to physical barriers, sympatric speciation happens within a shared habitat where a new species arises from a parent species while remaining in the same location. This can occur through mechanisms such as changes in food source, behaviors, or the establishment of new ecological niches within the same environment. An example of such a mechanism includes a subset of fish in a lake finding and exploiting a new food resource at a different depth, leading to reproductive separation from the original population over time.