Ligers & Tigons…good Evolution Or Not?
Filed in Category Answers about Ligers
Liger: the offspring of a male lion and a tigress. These can be up to 1000lb in weight, and approx. 12ft long. Males are said to be sterile (and therefore docile due to lack of testosterone) while females are generally fertile, which means they can never reproduce together. Female ligers can reproduce with either a male lion to create a li-liger or a male tiger to produce a ti-liger.
Tigon: the offspring of a male tiger and a lioness. They have never been known to grow any bigger than either parent. Again males (and again docile due to lack of testosterone) are said to be sterile whilst the females are fertile. Females can reproduce with a male tiger to create a ti-tigon or a male lion to produce a li-tigon.
So whilst these undoubtedly very beautiful animals satisfy the human fascination with large cats (especially ligers), they can never reproduce together to create a new breed of cat, and at present are only found in captivity, so can only rely on human intervention to keep them alive, as ligers particularly are thought to be far to big to hunt stealthily and bring down prey.
Your thoughts?
9 Comments so far
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They didn’t evolve, they were bred by humans to make money. They often have health problems, especially ligers because of their great size. Breeding them is pointless and cruel.
There are two reasons why evolution has nothing to do with this. One is, that lions and tigers don’t overlap in natural habitat, so they don’t get the chance to breed together. The other is, that as you correctly point out, any offspring they do have is at a disadvantage when it comes to surviving and producing offspring.
Go back far enough, of course, and lions and tigers have a common ancestor. Being geographically separated has made it easier for them to go their separate evolutionary ways.
Up to about 1-2,000 years ago, both tigers and lions lived in africa. So the african lions we see today I’d guess could have a lot of tigon ancestors. The exact effects this may have had on the ‘purebred’ lions before its surely near impossible to determine and probably not more than simple mutations that might have occurred since.
If they don’t reproduce, they are no part of evolution and therefore neither bad nor good for it.
And evolution is never good or bad – it just happens. They fascinate us, so they’re good. There is no reason for them to be bad.
It’s not evolution seen as how it was because of man that this happened…
Domestication is the opposite of evolution. Natural selection favors the individual able to reproduce the most offspring. Obviously sterile, artificial hybrids have no chance of survival and evolution would never produce them. The situation is similar to the creation of the mule, which is also sterile. One of the most surprising examples of evolution driven by humans is ordinary corn. It is a totally artificial organism which resulted from the crossing of two unrelated species of grass. It is now totally dependant on humans to reproduce, since unlike other plants, all the seeds are tightly packed in a husk and need to be manually opened to be dispersed. Amazingly enough, humans are not the only species which have taken control of evolution. Leafcutter ants cultivate fungus and this species is found only in the ant’s nest. Agouti are small forest rodents which the Brazil nut is dependant on for seed dispersal. The nuts are encased in a hard shell impossible to crack. Only the rodent can gnaw open the shell to get at the seeds, which themselves have incredibly thick shells. Like a squirrel, the agouti buries what it does not eat to store food, but forgotten nuts sprout into new trees. Brazil nuts are also totally dependant on several other rain forest species to reproduce successfully. The pollinator is a female bee who only mates if the male is wearing the aromatic oils collected from a rare Gongora orchid. Virgin bees do not rear young and never collect pollen. Thus, the Brazil nut tree is totally dependant on a rodent, an insect and an orchid to reproduce. The proof of this is that trees only produce nuts in undisturbed rainforest.
This is not really evolution – it is an entirely artificial situation brought about by humans. The only reason it is possible at all is that both species share a common ancestor recently enough in history that their mating behaviour and cross-fertility are partially compatible. Males are bound to be sterile as meiosis can’t take place ‘normally’ so spermatogenesis fails, females are able to ‘rescue’ the situation at times but for what purpose? It is an evolutionary dead end.
I am against such things – after all the animals concerned are under stress if they mate with a different species other than their own, which they would never do if left to their own devices (appalling animal welfare considerations) and also in the case of tigers in particular, they are an endangered species so why are humans forcing them into unnatural behaviours when it is essential to try at least to breed tigers to attempt to protect them.
In my mind this is a Victorian side-show, nothing more.
Ligers and Tions are nothing to do with alleged evolution!
Quite the opposite. They show that lions and tigers are the same ‘kind’ of animal, even though they are labelled as different species.
Lions and Tigers (and many other big cats) share common big cat ancestors. Natural Selection and variation has led to the many different species of big cats that we have today.
Note that all the current species have *less* genetic information than the original big cat ancestors. Natural Selection and variation is at best neutral and in practice, a downwards process.
Examples such as the Liger and Tion do not demonstrate evolution. They demonstrate that speciation occurs.
The original big cat ‘kind’ was created by God. It is an interesting question as to how many kinds of cats were created in the first place. Probably sabre-toothed cats were a different created kind, and maybe the currently living cats derive from more than one created kind.
First thing’s first: evolution has nothing to do with this. These cats are not wild and did not evolve naturally (Tigers: India, lions: Africa).
But ligers and tions are really only created for money, a kind of animal freak show. I think it was good that we did create them: playing around with genetics helps us to understand the way animals are put together. In this case we learnt about size genes.
Also…I am very, very annoyed at some folks who have hand-reared ligers. Lions and tigers being imprinted is bad enough, they can and do kill the idiots who trust them. But ligers are unstoppable, extremely powerful animals. The publicity that hand-reared individuals attract can only be bad: it encourages the already large exotic cat trade, and makes people think that a hand-reared lion or tiger is just as tame as a hand-reared housecat. Ligers should be given the respect they deserve, and left to the real experts…