quote:
Originally posted by Punisher:
I defer to Dr. Jonathan Sarfati: "One common definition of a species is a group of organisms which can interbreed and produce fertile offspring, and cannot mate with other species. However, most of the so-called species (obviously all the extinct ones) have not been tested to see what they can or cannot mate with. In fact, not only are there known crosses between so-called species, but there are many instances of trans-generic matings, so the 'kind' may in some cases be as high as the family. Identifying the 'kind' with the genus is also consistent with Scripture, which spoke of kinds in a way that the Israelites could easily recognize without the need for tests of reproductive isolation.
For example, horses, zebras and donkeys are probably descended from an equine (horse-like) kind, since they can interbreed, although the offspring are sterile. Dogs, wolves, coyotes and jackals are probably from a canine (dog-like) kind. All different types of domestic cattle (which are clean animals) are descended from the Aurochs, so there were probably at most seven (or fourteen) domestic cattle aboard. The Aurochs itself may have been descended from a cattle kind including bisons and water buffaloes. We know that tigers and lions can produce hybrids called tigons and ligers, so it is likely that they are descended from the same original kind."
Careful, now you're arguing common descent and descent with modification. Either there were immutable kinds (and you did originally define kind as species - no fair moving the goal posts and now claiming you
really meant genera), or there weren't.
Let's see if that holds up. You stated, or at least implied, that cats were all the same kind. Now I agree that the Aramaic-speaking people's that came up with the Genesis story didn't have advanced genetic sequencing techniques to really determine differences in "kinds". However,
we do. So it makes sense to take a look at one of these kinds and see if it makes sense. Even if the critters are not able to produce hybrids - like the ligers and tigons - if they are all the same kind, they should have approximately the same genetics, n'est-ce pas?
One way to genetically determine the relatedness of living organisms is to compare rare mutations or oddball insertions in the genetic code. Good ones for this purpose are retroviral insertions. Basically, a retroviral insertion is an old bit of left-over genetic code from a virus that infected the germline of an ancestral animal. Since it is neutral (assuming the the virus didn't kill the host or something) retroviral DNA will be inherited by descendants of the host. Again, this process is rare and fairly random, so finding retrogenes in identical chromosomal positions of two different species strongly indicates common ancestry. Within the
Felidae (cats), the standard phylogenetic tree (based on the usual morphological, biochemical etc features) has small cats diverging later than large cats, with the blackfooted cat
Felis nigripes being the first of the small cats to diverge. All small cats (from the jungle cat
F chaus, European wildcat
F silvestris, sand cat
F margarita, African wildcat
F lybica, blackfooted cat, to the domestic cat
F catus and margay
F weidii) share a specific retroviral gene insertion. In contrast, the cat lineages that diverged before the small cat lineage (lion, cheetah, and leopard) and all other carnivores lack this retrogene. Now it is incredibly unlikely that the cheetah or tiger, or some other mammal (dogs, or cows, say), could have this same retrogene in the same chromosomal location. None do. This means all the "little cat kind" are closely related genetically, whereas they are NOT as closely related as a group genetically to the "big cat kind".
The implication here is that whereas it
might be possible for various "little cat kinds" or "big cat kinds" to mate within their "kind", there is proof from genetics that they HAVE NOT DONE SO - in spite of the fact that many of these species have overlapping ranges, or have ranges that overlap with the other "kind" (ex.
Puma concolor and
F weidii). Oops, now you have two "kinds" where just a minute ago you had only one.
BTW: You should check out a good website on biodiversity or ecology. Even shifting the goal posts to genus and admitting the mechanisms of evolution leaves you with a HUMONGOUS problem of sheer numbers. You still have about 200,000 genera to deal with.
Does Safarti have anything to say about how they kept all those predators from eating all your cattle kinds?
™ Version 4.2