Posted: Sep 24, 2018 3:17 pm
by Wortfish
Calilasseia wrote:

Citation for this?

"Macroevolution is speciation":

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.

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.

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.

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?

Care to rework that last sentence into something resmbling 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.

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 ... :D

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.