Science

Click the video above to learn why hybrid species usually can’t produce offspring.

 

Hybrid animals are the offspring of two animals of different breeds or species, especially as produced through human manipulation for specific genetic characteristics. While, hybrid animals can occur naturally in the wild, they are much less likely to happen without human interference. Hybrids were initially produced for their genetic benefits. For example, mules are often used for farming and hauling loads. Mules are the cross between horses and donkeys and are preferable for farming since they are larger than donkeys and sturdier than horses. However, the positive characteristics of hybrids come with negative aspects as well since almost all hybrids are infertile and suffer from serious health issues.

Hybrid animals are infertile because they don’t have viable sex cells, meaning they can’t produce sperm or eggs. This is the case because the chromosomes from their different species parents don’t match up. Non-hybrid animals’ normal body cells contain two copies of each chromosome. They receive one copy from the mother and one copy from the father. When both an animal’s parents are of the same species, switching out the father’s chromosome for the mother’s doesn’t cause any problems. However, when the animal’s parents are from different species, their chromosomes don’t match up. For example, during the creation of sex cells when chromosomes get swapped, an eye color chromosome might get exchanged with a paw size chromosome.

Unsurprisingly, the contrasting chromosomes can also lead to severe birth defects. Many zebroids suffer from dwarfism and big cats, specifically ligers, suffer from unsustainable growth. In the case of the ligers, their unsustainable growth can lead to their hearts giving out. According to Susan Bass, director of public relations for Big Cat Rescue,  “Their organs literally can’t handle the weight.”

These are just a few examples of the severe repercussions of crossbreeding animals. Although hybrid animals are amazing to look at and can have helpful genetic modifications, the negative aspects of hybrids prove that just because you can interbreed species doesn’t mean you should.