LIGERS AND TIGLONS AND URSIDS, OH MY! –EVOLUTION IN THE MAKING

Here’s another flashcard in the ongoing debates about evolution.

We’ve all heard the tired old refrain – “Show me where new species have come into existence!”

And so, I give to you, ligers, tiglons, and ursids.

Also wholphins, coydogs, dogotes, coy-dingoes, guin-hens and pea-guineas, dzos and zorses, not to mention zedonks and zonies.

These are all interfertile species, known as hybrids.

Of course, the response will be: “Hey, the horse is an entire species!” or “Hey, tigers and lions are all the same species, they’re cats!”

Not even close. Kinda like saying a tree and a weed are in the same species. Family? Yes. Species? No.

The Science dictionary defines it as “In biology, the classification lower than an order and higher than a genus. Lions, tigers, cheetahs, and house cats belong to the same biological family. Human beings belong to the biological family of hominids. (See Linnean classification.)”

Linnean classification catalogues it thusly: “A way of organizing living things. In biology, plants and animals have traditionally been classified by the structure of their bodies, in a descending hierarchy of categories: kingdom, phylum, class, order, family, genus, and species. For example, human beings are classified as belonging to the animal kingdom, the phylum of chordates, the class of mammals, the order of primates, the genus Homo, and the species sapiens.

The scheme is based on a system developed by the Swedish scientist Carolus Linnaeus in the eighteenth century.”

Note the phrase: descending hierarchy – the list ascends, top to bottom, species being the bottom rung of the ladder.

That out of the way, let’s looks at the wholphin, that mix of Flipper and a fake Shamu.

“A wolphin or wholphin is a rare hybrid, formed from a cross between a bottlenose dolphin Tursiops truncatus (mother), and a false killer whale Pseudorca crassidens (father). Although they have been reported to exist in the wild, there are currently only two in captivity, both at the Sea Life Park in Hawaii.”The next portion, while it illustrates natural selection perfectly, regrettably, shows why they aren’t all that prolific:

“The wolphin proved fertile when she gave birth at a very young age. The calf died after a few days. However, in 1991, Kekaimalu gave birth once again, to daughter Pohaikealoha in 1991. For 2 years she cared for the calf, but did not nurse it (it was hand-reared by trainers). Pohaikealoha died at age 9. On December 23 2004, Kekaimalu had her third calf, daughter Kawili Kai. This calf did nurse and was very playful. Only months after birth, it was the size of a 1-year-old bottlenose dolphin.”

What about the liger, you ask?

“The liger is a cross (a hybrid) between a male lion and a female tiger. It has also been known as a lion-tiger mule. A liger looks like a giant lion with diffused stripes. Some male ligers grow sparse manes. Like tigers, but unlike lions, ligers enjoy swimming. Unlike other hybrids, female ligers can reproduce.

A cross between a male tiger and a female lion is called a tigon. ^[1] This would have referred to the Gir Forest in India where the ranges of Asiatic Lions and Bengal Tigers overlap. Under exceptional circumstances it has been known for a tiger to be forced into ranges inhabited by the Asian lion, Panthera leo persica, which is the same genus as the tiger. Reports have been made of tigresses mating with lions in the wild and producing offspring known as ligers.”

And before you cry ‘Mule!’, witness:

”Male ligers are sterile, but female ligers are fertile and can breed with tigers (resulting in ti-ligers) or to lions (resulting in li-ligers).
Ti-ligers are more tiger-like, having a greater percentage of tiger genes. Li-ligers are more lion-like, having a greater percentage of lion genes. The fertility of hybrid big cat females is well-documented across a number of different hybrids.
This is in accordance with Haldane's rule: in hybrids of animals whose gender is determined by sex chromosomes, if one gender is absent, rare or sterile, it is the heterogametic sex (the one with two different sex chromosomes e.g. X and Y).”

In most cases, it’s almost always the female that’s fertile, the male sterile.

And, for a taste of East meets West, there’s the yakalo:

“The bison (American "buffalo") has also been bred with the domestic Tibetan yak to create the yakalo. In Nepal, yak/cattle hybrids are bred using yak bulls with domestic cows or, less often, domestic bulls with yak cows. The yak/cow females are fertile, the males are sterile and the meat is generally considered superior to beef among gourmets. In Nepalese, the hybrid is called a khainag or dzo (male)/dzomo (female). A dzomo crossed with either a domestic bull or yak bull results in an ortoom (three-quarter-bred) and an ortoom crossed with a domestic bull or yak bull results in a usanguzee (one-eighth bred). As a result, many supposedly pure yak and pure cattle probably carry a dash of each other's genetic material.”

There’s actually a very, very long list of creatures that range from the Jaglion to the Lepjag, to Camas and the beefalo.

Not to be confused with chimeras, such as Lydia Fairchild, or the tortoishell cat.

And here, is the pivotal crux: if Ligers or Tiglons become extinct, then they can be brought back into existence, easily.

So carry this around in your backpocket: and the next time some creationist doof starts yapping about 'no new species', enjoy the resulting confusion when you spring this little ditty on their blinkered viewpoints.

Till the next post, then.