Posted: Sep 24, 2018 4:07 pm
Obscure source (and one that took three minutes to load on a broadband connection that normally handles such matters in 5 seconds), but for once, not the usual duplicitous creationist output. Makes a pleasant change.
But of course, those of us who paid attention in class, understand that any evolutionary process generates biodiversity, regardless of whether or not it results in a speciation event. Because at bottom, biodiversity is simply genetic diversity within biosphere populations.
Moving on ...
Wortfish wrote:Do tell us all why that definition is "shallow and cautious". Preferably with reference to some actual biology to support this assertion.
I mean that such a definition in no way implies universal common descent. It just means that a group or population can become reproductively isolated.
Wrong. It does imply universal common descent, courtesy of the fact that current populations inherited their genetic constitution from relevant ancestors. You do know what the word "inherit" means, don't you?
Wortfish wrote:Quite simply, the higher taxonomic divisions, are divisions humans formulated for their cataloguing convenience, and at bottom, nothing more. Though I'm familiar with the manner in which not only creationists, but other religious fundamentalists, have a habit of treating words in a book as somehow magically dictating to reality how it behaves, regardless of whether or not reality pisses itself laughing at such hubris.
The only taxonomic division that is properly defined is the species. All others are arbitrary.
Oh wait, this is exactly what I was telling you in the above post. You want a cookie for working this out?
Wortfish wrote:Do they? Should I care about this? Or should I, more properly, be suspicious of their trying to force-fit biological data into a doctrinal framework, for the purpose of propping up pre-scientific mythology?
Of course. Because if a pari from every species around today was on board the Ark, it would have sunk! Not so with the kinds.
Once again, point me to a definition of "kinds" that doesn't involve the comedy of the absurd.
Wortfish wrote:Er, do come back when creationists have something other than a morass of comedy fabrications, with respect to the matter of defining "kind" ... which none of them have been able to do.
Do you deny that there exists man-kind?
This is a colloquial term. F for effort.
Wortfish wrote:Care to rework that last sentence into something resembling conventionally parseable English? Of course, if you're trying to assert here, that being able to produce offspring, sterile or not, is a diagnostic criterion for "kind", then you have a problem, because there are documented instances of closely related species that will not produce offspring of any sort if you hybridise them. Indeed, I've alighted upon an example of an organism that uses sex as a biological weapon to eliminate food competitors, that provides a prime example of this. Hesperocimex cochimiensis and Hesperocimex sonorensis are two species of Hemipteran bugs, that compete for a food source - they're blood feeding parasites of owls in their natural habitat. It's been found that if a male H. cochimiensis inseminates a female H. sonorensis, the result is that the H. sonorensis female dies from a massive immune reaction to the H. cochimiensis sperm. Just to add to the fun inolved, like numerous other Cimicid bugs, these species aso indulge in hypodermic insemination, which adds its own spice to the proceedings.
There may be some reproductive barriers to closely related species being able to produce offspring. But we can use genome transplants in such cases.
Except that oops, this is currently a laboratory technique deployed by humans, not something that occurs in the biosphere. As for horizontal gene transfer, this is mostly restricted to bacteria and archaea. It's not documented as occurring between multicellular eukaryotes as far as I'm aware.
So basically you're appealing to magic again here?
Wortfish wrote:Another fun example from the world of invertebrate zoology, is provided by Skipper butterflies (Family Hesperiidae). Members of the Genus Erynnis have been documented for some time as possessing asymmetric genitalia, making them stand out from the majority of other Lepidoptera, in which the genitalia are bilaterally symmetric. However, two American species in the Genus, Erynnis funeralis and Erynnis propertius, have secondarily re-acquired symmetry in their genitalia, which means they're now mechanically incompatible for hybridisation with other members of the Genus in their locality. I really love the way biology repeatedly pisses all over creationist pretensions ...
As I said, just because some beetles are too small to mate with larger beetles, doesn't mean that they are not descended from a common beetle type or kind.
I don't recall molecular phylogeny saying anything different. Except of course that molecular phylogeny doesn't introduce an arbitrary limit upon common ancestry. So do please tell us all once and for all, how this arbitrary limit is drawn, and for what biologically sound reasons, as opposed to blindly asserting that such a limit exists, in a desperate attempt to prop up mythology written by people who couldn't count correctly the number of legs that an insect possesses.