They are rare, but not as rare as you might think. Strange hybrids of animals in the wild attract the attention of biologists. From a genetic point of view, a hybrid animal is the result of crossbreeding between divergent lineages. Why do these unusual species arise?
One of the best known examples of hybridization is the so-called liger. It is a cross between a male lion and a female tiger. Less common is the tigon, the offspring of a female lion and a male tiger. Both pairings are very unlikely in the wild. The home ranges of lions and tigers almost never overlap. The same is true of the litter. It is a cross between llama and dromedary camel. They live on different continents, but appeared in breeding grounds.
Numerous species
Equids may be especially prone to hybridization. Donkeys and horses can breed to create mules. Zebras and horses give rise to zorses (or zebras). Narwhals sometimes hybridize with beluga whales, giving rise to a narwhal. Pass between Cuban and American crocodiles, Russian sturgeon and American paddlefish, cutthroat trout and rainbow trout.
It also passes in various insects, such as ants, bees, wasps and termites. Plants are especially capable of hybridizing. They do so at an even higher rate than animals. Hybridization is quite well known also in butterflies.
Climate change will influence strange animal hybrids. If there is less ice, polar bears will often meet brown bears.
Hybridization can be problematic if one or both parent species are endangered. What happens when the genetics of a species become rare? The new genetic combination of the hybrid can threaten its existence by replacing it. This is called genetic flooding. The existence of red wolves in the United States is thus threatened by hybridizing with coyotes.
Potential benefits
You can also introduce beneficial genes, such as pesticide resistance. If those genes help the hybrid survive and reproduce, those benefits can become widespread in a population. This is what scientists call adaptive introgression.
