Here's why:
* Species Definition: A species is a group of organisms that can interbreed and produce fertile offspring.
* Hybrids: Ligers are hybrids, meaning they are the result of crossbreeding between two different species.
* Infertility: The infertility of ligers indicates that their parents are genetically distinct enough to make their offspring unable to reproduce.
While lions and tigers can interbreed, their offspring are not viable in the long term for continuing the genetic line, highlighting the distinct nature of these two large cat species.