nested heirarchies as evidence against darwinian evolution

I hope I can start this back up with a more civil tone. I'd like to start more or less at the beginning again, with one of randman's 3 original points. Specifically, the first one:

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1. Essentially except one possibility around 470 million years ago, all animal phyla had appeared or evolved around the time of the Cambrian explosion 500 million years ago. Since that time, no new animal phyla have appeared or evolved IN 500 MILLION YEARS. Apparently whatever processes or creative events that evolved, created or animated the appearance of the animal phyla has not been in process for the past 500 million years. If it had, we would see new phyla emerging and we do not. Certainly, there have been quite a few extinctions during that time to open ecological niches up.

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This is really a semantic argument stemming from the common Western-Hemisphere cultural obsession with defining and categorizing things. The word "phylum" doesn't mean anything in particular: it was coined before evolutionary theories had really taken hold in science, and so is erroneously applied to evolution. It is most often defined in terms of its position in the nested hierarchy of descent, which requires it to be a very old lineage.All animals found in the Cambrian deposits were fairly simple types. The one chordate found, Pikaia, only has a notocord, and apparently no real skeleton. In fact, Pikaia looks more like the other soft-bodied, wormlike organisms of its time than it does like any of its purported modern descendants (the modern chordates, including us). So, the first member of what we call a "phylum" is not going to be a completely distinct organism, but will be derived from already existing stock, and its descendants will only later become sufficiently distinct to merit the title of "phylum." That's where the idea of nested hierarchies comes into play in support of evolution.In summary, if you define a phylum by its level of distinction from other groups, of necessity you require it to be something that had its origin a very long time ago. This is because, according to evolutionary theory, it takes a long time for significant changes to occur. So, the ancestors of tomorrow's new phyla are evolving today, in the form of new species, new genera, and new families. Each species holds the potential of diversifying into a genus, and each genus, of diversifying into a family, and so on.Edited by bluejay, : Grammar.

Thanks, RAZD. I think that was kind of the point of the Linnaean system: to define exactly how closely related animals were to each other. But, Linnaeus was a creationist, and believed in the immutability of species. So, "relatedness," in his opinion, meant "similarity."Today, "relatedness" is generally held to mean "time since the divergence from the last common ancestor." This has obviously required adjustments to Linnaeus's system, however.On to randman's second point: The part that I want to draw your attention to is the part where it reads "almost everyone had the point of a 'common ancestor'... undiscovered yet." If even only one or two of these 'common ancestor points' (as they're called here) had been discovered, it would completely and utterly destroy the creationist model.Either that, or creationists would have to accept that the biblical "kind" is much more expansive than they commonly believe. If birds are considered part of the "reptile kind," and stegocephalians are considered part of the "fish kind," the "kind" concept may have to be drawn back to "vertebrate kind," or even, "animal kind," which would essentially admit that evolution was true, with the caveat that animals can't reproduce with mushrooms and plants can't reproduce with slime molds. That's not a problem for evolutionary theory, though.This is largely a semantic argument, though, and may very well be invalid. I suggest somebody produce this chart: I want to see it myself.Edited by Bluejay, : Addition

I might as well add my input. Maybe it would help if you imagined horizontal lines going across the diagram. Each of those lines represents one point in time. Everywhere it crosses the descent lines is one species or group or population that existed at that time.Drawing a horizontal line lower than the vertical position of the black dot clearly shows that the black dot no longer exists in the form of the black dot. Only its descendents exist. Nature has lost the opportunity to make the black dot evolve further. This is the same thing as what I just explained above. Just like women hit menopause, and just like entire tribes of Native Americans were wiped out by Europeans (and other tribes), the original dot has only so much reproductive potential in it. Once its entire population has changed into something else or gone extinct, the original gene pool is essentially gone. The "information," if you will, has been fragmented and mostly lost, and there is no way to get it back together again without having wombats interbreed with sea urchins.

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Signed,
Nobody Important (just Bluejay)

Here's how NosyNed phrased it on a recent thread about this topic: The non-human apes are our cousins. We share an evolutionary great-great-grandparent (or something like that) with them, but they evolved from one of our great-uncles. That great-uncle was not the same kind of ape that we see today. We did not evolve from chimpanzees anymore than you were born to your aunt.In the opening post of this thread, randman asserts that, if evolution were true, we should see new cousins to today's phyla evolving today, just like we see our primate cousins evolving today along different lines from us. However, the common ancestor between us and the great apes is extinct, so any new developments will only come from other apes or humans. Likewise, the common ancestors of today's animal phyla are also extinct, so the only new lines that will evolve will come out of existing phyla.Edited by Bluejay, : grammar

The word "coelacanth" refers to an entire family (maybe superfamily or even suborder, I'm not sure) of fish that had its origins at least as far back as the Devonian Era (around 400 million years ago). Today's coelacanths (2 species) come from the genus Latimeria, which does not appear anywhere in the fossil record. The two living species are not the same as the ancient coelacanths, and have changed quite a bit since then.For instance, modern coelacanths are adapted to very deep waters, and, in fact, cannot stand the low pressures of shallower waters. Many, if not most, of ancient coelacanths were not deep trench fish: that is why we often found their remains on what used to be shallow reefs and shorelines.Just because the modern coelacanth looks a lot like ancient coelacanths, doesn't mean it hasn't changed in 400 million years. It is a different animal. Therefore, even though I understand your argument, it is invalid because the premise that coelacanths haven't changed is false.

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Signed,
Nobody Important (just Bluejay)

Okay, Boss: We'll get back on track.Here is a question from DogtoDolphin that provides a segue back to the original topic: This is a function of the concept of nested hierarchies. There is no "pinnacle" in evolution, because evolution is not the Great Chain of Being, as people used to think (that link leads to the Wikipedia article on the Great Chain of Being, which is a decent introduction). Evolution does not occur in a line, with the "highest" organism at the top and the "lowest" organism at the bottom.Rather, lifeforms diversify, with one parent speces giving rise to two, three, four, or more daughter species. Each of those daugther species can give rise to others. Therefore, there is a fan-like expansion from each point of divergence, each arm of which gives rise to more fans. Thus, each fan is "nested" within another fan.We (humans) are only only little line poking out of one little fan of literally millions, each of which is pointing out in different directions and has an entirely different lineage from the beginning until now. See This post for a visual.This thread started with the idea that these nested hierarchies) support creation, not evolution. However, the realization that we humans are only one of the youngest, tiniest branches in the big tree of evolution should be taken as a good indicator to us that God (assuming he exists, and created everything) doesn't see us as anything special, just because we make cars and computer and nuclear bombs. Actually, it seems like He's put more effort into making slime molds and flies than into making us.Furthermore, each animal and plant and fungus has a unique evolutionary history, some of which date back further than ours, and involve several more intermediaries (which relates to more "effort" to get to their current state). So, I wouldn't call us the "pinnacle" of anything evolutionary.And, on another note: the ability to destroy everything is often very anti-Darwinian in nature, because natural selection works toward "survival," not self-destruction. Thus, we could be considered the least evolutionarily "fit" species currently in existence.

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Signed,
Nobody Important (just Bluejay)

I also add my welcome to you, Pumaz. I'm fairly new, myself, but I've been very pleased with this discussion board so far. I agree that you've hit the crux of the matter with this statement. The notion that a new phylum could emerge first makes the assumption that the mainstream ToE is incorrect, thus rendering the argument tautological. I think it's also telling that modern taxonomy is moving, by degrees, away from the usage of such terms as "phylum." In fact, the phyla currently recognized are not actually equally placed in the hierarchies. Thus, we get groupings of phyla into "superphlya" or "subkingdoms": Arthropoda+Tardigrade+Onychophora=Ecdysozoa. Mollusca+Annelida+(several phyla of "worms")=Lophotrochozoa.We instead prefer to use the word "clade" to describe any cluster of related taxa, without applying absolute naming strategies to any level in the endlessly-complicated "tree of life."My personal opinion is that, if we wanted to continue using distinctive terms like "phylum," "order" or "species," we would have to change their meanings slightly as evolution continued. For instance, in 100 million years, vertebrates will likely have diversified into a wide variety of lineages that are as distinct from one another as today's molluscs are from today's annelids. Under those conditions, I think it would be appropriate to rename such subgroups "phyla," given the definition of distinctiveness (as I have championed in this thread). If you view distinctiveness as insufficient to merit a renaming strategy, I would submit that any alternative method is largely arbitrary (such as RAZD's idea of hierachies defined by increments of time).As RAZD also pointed out earlier in the thread, randman might be thinking, since we evolved from basal eukaryotes, and "basal" eukaryotes still exist, that something else should be able to evolve from the remaining groups of basal eukaryotes, just as we had. The answer to this concern is, of course, that other things did evolve from basal eukaryotes. In fact, what he may be seeing as "basal eukaryotes" today are actually the derived ancestors of the things from which we evolved, and not the same plesiomorphic organisms that their ancestors were. In other words, today's bacteria are just as evolved as we are, they just evolved in a different direction from us.Edited by Bluejay, : Grammar.

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Signed,
Nobody Important (just Bluejay)