A particular species of fish were spilt by the formation of the isthmus of Panama a long time ago . The fish developed changed in their genes to adapt to the new environment and became two different species. What is this process called

Explanation:

Allopatric speciation is the formation of species due to geographical barriers like continental drift, origin of mountain, origin of ocean, etc and such type of speciation is called allopatric speciation

In case of the given species of fish they were split by the formation of the isthmus of Panama a long time ago as a result fish developed changes in their genes to adapt to the change in environmental conditions hence resulted into two different species which clearly represents allopatric speciation

the answer is d.) homologous; have mammary glands