Here's why:
* Different species: While they both belong to the deer family (Cervidae), they are separate species with distinct evolutionary paths.
* Chromosomal differences: The number and structure of their chromosomes differ, making it impossible for their genetic material to combine correctly.
* Reproductive isolation: Their mating behaviors and physical differences prevent them from successfully mating.
Although they may share similar habitats and even graze in the same areas, elk and white-tailed deer are reproductively isolated and cannot produce viable offspring.