tag:blogger.com,1999:blog-6030110973061875792.post3753592502033184633..comments2024-03-16T21:32:23.088-04:00Comments on A Sure Word: “Kinds” versus “species”RKBentleyhttp://www.blogger.com/profile/00566375018731000081noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-6030110973061875792.post-60382725915619455122016-12-23T23:48:42.450-05:002016-12-23T23:48:42.450-05:00Okay, I agree with your point that asking you to d...Okay, I agree with your point that asking you to define "kind" is a red herring <i>in the particular instance noted</i>. I'm not sure whether anyone has actually asked a creationist to do that in this particular instance, though. In a more general sense, though, saying that speciation and descent with modification is possible "within kinds" but not "between kinds" does indeed create an obligation to define "kinds," since otherwise this assertion has no discernible meaning.<br /><br />With silver foxes, Belyaev started with a lot of foxes, and produced an animal that is roughly as different from the wild type of silver fox as, say, a collie is from a wolf. Starting with one breeding pair and producing dozens of different species within even a few hundred years is a rather more formidable problem (in that you have both much less genetic variety and far fewer opportunities to [a] generate new variety through mutation and [b] combine that new variety in various ways). I'm not saying that nothing can be done; apparently all pet hamsters on the planet are the descendants of a single pregnant female captured back in 1930, and quite a few obvious mutations (in coat color, etc.) have occurred and been spread among her descendants in less than a century. But, as I'd expect a creationist to note, they're all still <i>Mesocricetus auratus</i>.Steven J.https://www.blogger.com/profile/15638850493907393069noreply@blogger.comtag:blogger.com,1999:blog-6030110973061875792.post-43493168434845745212016-12-23T07:30:27.957-05:002016-12-23T07:30:27.957-05:00Steven J,
I agree that kinds are immutable. I do...Steven J,<br /><br />I agree that kinds are immutable. I don't agree that we should be able to easily recognize the members of a kind. If I remember correctly, bison and cows were not even considered the same genus before it was discovered they could hybridize. Technically, that would make them the same species. Certainly they're the same kind but their anatomical differences obscured that fact. I've also read about a psuedo killer whale and a dolphin that reproduced in captivity. I wouldn't be surprised if killer whales and dolphins were the same kind.<br /><br />I believe defining a kind is fairly easy. Identifying all the members of a kind, not so much. The ability to reproduce across species is conclusive but not practical since we can't easily attempt to cross breed every single species. It's also impossible in the case of extinct creatures and asexual creatures. The inability to reproduce isn't necessarily a disqualifier either since sometimes anatomical differences have become so great that mating is no longer possible (as in very large and small dogs).<br /><br />To your point on feline variation, I'm a little less incredulous than you. I believe house cats can reach sexual maturity in less than a year. They also have a few kittens in each litter. You'll recall I talked about the Russian experiment with the foxes. In that case, marked differences in appearance and behavior were achieved in only 8 generations. I believe remarkable changes in cats could occur in just one century.<br /><br />Finally, if I had to assign an equivalent, secular term to kind, it would be close to family. Of course, it's not exactly the same as family. In the case of cats, I understand that some creationists put only members of the genus Panthera in the same kind. I don't necessarily agree but, hey, what's the big deal? It would be nice to have a tidy chart correctly categorizing every known organism but I'm not sure how it's absolutely necessary. <br /><br />You didn't comment, though, on my point that many evolutionists seek a definition for kind only as an attempt to derail the conversation. Do you agree that evolutionists should at least understand the term well enough to have a discussion without demanding that we not only define the term but also that we be able to correctly categorize every creature of a kind?<br /><br />Thank you for your comments. God bless!!<br /><br />RKBentleyRKBentleyhttps://www.blogger.com/profile/00566375018731000081noreply@blogger.comtag:blogger.com,1999:blog-6030110973061875792.post-22501639955000488262016-12-17T19:23:49.870-05:002016-12-17T19:23:49.870-05:00You raise the point that young-earth creationists ...You raise the point that young-earth creationists don't dispute that speciation can occur. I note that, first, old-earth creationists do in fact often dispute that very point, and second, that some young-earth creationists have <i>said</i> they dispute it (the problem arises because of non-standard use, by creationists, of standard biological terms; I recall one creationist who claimed that woolly mammoths and African elephants were the same "species" -- surely he meant "kind"). Creationists' wilful failure to use terminology correctly engenders confusion in evolutionists who try to understand the creationist positions.<br /><br /><b> A species is a population of organisms that have enough traits in common that they can be identified as belonging to the same group. </b><br /><br />Well, so it is. But that definition works equally well for "genus," "family," "order," "class," and "phylum" (a few centuries ago, people could tell that trilobite fossils belonged to the same general group as lobsters and insects -- though obviously they recognized that they weren't lobsters or locusts). For a single, general definition of "species" (biological sciences have thirty-odd different definitions, advanced by various scientists to deal with various problems, such as organisms that don't reproduce sexually and fossils that don't reproduce at all), I'm not sure that we've moved beyond John Ray's 17th century definition that species produce offspring of the same species (in which case, we can actually make sense of the claim that the evolved viruses were two new species -- neither was the sort of virus that the original ancestral virus would have caused <i>E. coli</i> to make new ones of).<br /><br /><b>I talked in my last post about how they casually use the word theory but harp on creationists for calling evolution a theory.</b><br /><br />Well, yes, but the point is that creationists treat "theory" as some inferior rung on an epistemic ladder, and insist that common descent and adaption by natural selection need not be taken seriously until it reaches the rung of "fact" or "law." No matter how well-substantiated and comprehensively confirmed a theory is, it remains a theory -- calling something a "theory" is not a confession that it rests on guesswork or conjecture.Steven J.https://www.blogger.com/profile/15638850493907393069noreply@blogger.comtag:blogger.com,1999:blog-6030110973061875792.post-86667769549201638292016-12-16T09:53:25.395-05:002016-12-16T09:53:25.395-05:00Here is the most striking difference between "...Here is the most striking difference between "kinds" and "species." If humans share common ancestors with baboons and bass, species are temporary (even if we ignore extinction) and fuzzy categories: there must be intermediate forms in time, and often will be in space (e.g. "ring species" and cases where experts cannot agree whether two populations are separate species or merely separate subspecies). If special creation is true, then "kinds" must be fixed and immutable and (barring extinction) permanent. Evolution implies that there is a certain arbitrariness in all biological classifications (like naming the colors of a rainbow or setting legal ages to do various things, you're drawing lines on a continuum); creationism implies that one particular biological classification is an absolute fact -- changes in gene frequencies within a population cannot, no matter how much time or mutation or selection pressure is available, change the population into a different "kind."<br /><br />This seems to imply that "kinds" ought to be recognizable, marked by distinct features that limit change and delineate them from other "kinds." One would think that if this were true, taxonomists would notice these features and use them, with the result that "kind" boundaries would in fact correlate to some particular Linnean rank (e.g. not just "roughly the equivalent of Linnean families," when they're not roughly the equivalent of Linnean genera or Linnean suborders or whatever). "Kinds" ought to be easier to define and recognize than species, if they actually exist.<br /><br />I do find myself sharing your bafflement at viral speciation; indeed, it's been pointed out that "species" is a difficult category to apply even to indisputably living bacteria -- they don't mate, but they do share genetic material ("bacterial sex," although it's more like individual bacterial genes opting for free agency) across what are commonly treated like generic, family, order, or even class or kingdom lines.<br /><br />On the other hand, surely you can see that it makes a difference whether something can undergo hundreds of generations in a day or one or two a year -- or one or two a decade. To get house cats and lions (very often treated as a single "kind" by YECs) within a few hundred years, tops, of the Flood (since they are depicted as quite separate species in ancient Egyptian art) is a very formidable task, and not the biggest degree of "change within kinds" that creationists have proposed; at least two young-earth creationists (Todd Woods and Kurt Wise) have proposed that the entire suborder Caniformia is a single "kind" derived from a single pair of ur-caniformes aboard the Ark. The Caniformia includes not merely dogs and foxes, but all bears and all seals, among other groups.Steven J.https://www.blogger.com/profile/15638850493907393069noreply@blogger.com