In December 2011, a lioness at Yancheng Safari Park of Changzhou in China gave birth to twin tigons, and the Associated Press recently released footage of the young cats in their pen. Tigons, or tiglons, are the rare products of tiger fathers and lioness mothers. Tigers are larger cats than lions, leading to more difficulties in pregnancy and birth with tigons than with ligers. Unfortunately, one of the featured tigons died soon after birth.
“Recently” here is early March, which has got to be a record (judging by the ‘accessed on’ dates, this article was written over a month ago – also a record?). Anyway:
In short, lions and tigers can interbreed because they both descended from an ancestral cat family. Scientists place different cats on a continuum of interbreeding varieties. For example, house cats can interbreed with small feral and other wild cats. They descended from the African wild cat. Small wild cats have, in turn, interbred with larger wild cats. Leopards and panthers can interbreed. All of this breeding potential clearly shows that different cats are varieties within the same basic cat kind.
Thomas is trying to prove the following:
Tigons and ligers, as well as all cat varieties, are most easily explained in the Bible’s historical context.
He bases this on the entirely sourceless claim that:
If evolutionary time were true, then many more cat varieties probably would have lost the ability to interbreed after so many years in reproductive isolation. Instead, because the cats have only been isolated from one another for thousands and not millions of years, some cat varieties retain potential to interbreed when brought near to one another.
His implication from the second paragraph I quoted is that all ‘cats’ (family Felidae) can interbreed, or at least that there is a continuum between them.* He states this more explicitly like so:
This is exactly what one would expect from the early Genesis record. Creatures were designed to reproduce “after their kind.” Creatures were also designed to “multiply and fill” ever-changing environments. In the process of filling the post-Flood world, the cats on board the Ark rapidly diversified into the varieties known today, as well as extinct varieties like the saber-toothed cat.
Now the cat family is reasonably large, and contains a number of subdivisions. For example, the tiger/lion cross is an example of hybridisation only within the same genus (Panthera) – ditto leopards and panthers (though this is complicated a little because there is not really such a thing as a panther, and you can even get cases when leopards are called panthers). House cats can indeed interbreed with the wild varieties from which they were domesticated. The line “Small wild cats have, in turn, interbred with larger wild cats” is ambiguous and unspecific. All and all a continuum is far from proved – not that that makes any difference for the reality of evolution.
As I alluded to before, the attack on evolution is baseless. B.T. cannot come up with examples of anything more than quite closely related species that can interbreed, and we have only his (valueless) word that what is observed is inconsistent with evolutionary time-scales.
Ring species are often brought in when arguing against kinds, where all neighbouring groups of organisms can interbreed but where the ends meet they cannot. This apparent change of tack, where kinds need not all be able to interbreed here and now, may well be in response to such criticisms. The result is a much better (i.e. not quite as horribly flawed) definition when it comes to fitting the observed reality, but it leaves us on the slippery slope to “they’re different kinds because I said they are.”
Somebody needs to tell Brian that he has adjusted his interpretation of scripture to fit the evidence, and that he’s half-way to conceding common ancestry.
*Evolution, specifically common ancestry, would have it that there should always be a continuum going backwards and then forwards in time between any two species, via their common ancestor. Though the possibility of instantaneous speciation means that nearby animals in that continuum may not always be able to interbreed, they are still able to be each others parents and children (because they were).