I gave you more than one link.
Wiki??? You would be lost without wiki lol
Try this one
Type 3
hybrids are
fertile and there is recombination during gametogenesis allowing introgression in further generations. Non-human-induced
hybridization represents
hybrids naturally found in nature, in which evolutionary opportunities arise when
hybrids are
fertile.
Harmonizing hybridization dissonance in conservation.
You posted links that you did not understand and the simple Wiki link refuted you.
It is incorrect to claim that Ligers are "fertile" in the sense that you are using the word. Males are sterile. Females have very limited fertility. It is a breeding dead end. You are just grasping at straws, the sort of action that a creationist often takes.
Ernst Mayr is credited with developing the modern biological definition of species:
:A species consists of a group of populations which replace each other geographically or ecologically and of which the neighboring ones intergrade or hybridize wherever they are in contact or which are potentially capable of doing so (with one or more of the populations) in those cases where contact is prevented by geographical or ecological barriers
The reason that Ligers and Tigons fail is that they are of limited fertility. The males are sterile. I can quote the Wiki article, I can quote other sources. The females may have babies but they tend to be rather frail. The Wiki article mentions two, count 'em two examples of a liger or a tigon having offspring:
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 sex is determined by
sex chromosomes, if one of the two sexes is absent, rare or sterile, it will be the
heterogametic sex. Male ligers are consequently sterile, while female ligers are not.
Ligers and tigons were long thought to be totally sterile. However, in 1943, a fifteen-year-old hybrid between a lion and an island tiger was successfully mated with a lion at the
Munich Hellabrunn Zoo. The female cub, though of delicate health, was raised to adulthood.
[24]
In September 2012, the Russian Novosibirsk Zoo announced the birth of a "
liliger", the offspring of a liger mother and a lion father. The cub was named Kiara.
[25]
There have been hundreds of ligers and tigons over the years since it was found that they could interbreed and only two offspring of either tigons or ligers. Offspring that would not have survived in the wild. They are two far past the speciation event for them to interbreed the way that dogs and wolves can do. Or that even wolves and coyotes can. By the way, this sort of "fuzzy" definition of species is what is expected if evolution is correct and cannot be explained by creationism.
As two populations separate the two groups will first tend not to interbreed merely because of coloration differences and other minor changes. Technically they are still the same species at this point because the hybrid offspring will be fully fertile. Dogs and wolves are an excellent example of this. Most of the times the two will kill each other in the wild, but sometimes they will breed. Given more time as separation continues fertility problems begin to arise in breeding between when members of the two different groups mate. Given enough time it gets past the point of no return. Tigers and Lions are past that point. They can be forced to breed, but only the female offspring are fertile and their fertility is extremely limited and does not appear to produce young that would reach adulthood in the wild. Given a bit more time and we have the case of the horse and donkey which produce mules which are almost always sterile. I say almost always because I am sure of at least one and there is probably two known cases of a fertile jenny. The males again are sterile. But that is in a period of over two thousand years. If there is even more time no offspring are produced.
