Final answer:
Closely related species share a recent common ancestor and have a high degree of genetic similarity. They often have similar physical features and genomes, known as homologous structures. Closely related species can also reproduce with each other, creating hybrid individuals.
Step-by-step explanation:
When two species are described as being closely related, it means that they share a recent common ancestor and have a high degree of genetic similarity. These closely related species often have similar physical features and genomes, known as homologous structures. For example, the bones in the wings of bats and birds have homologous structures. Closely related species can also reproduce with each other, creating hybrid individuals that belong to the species of their parents' common ancestor.