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Author | Topic: A response to evolutionists | |||||||||||||||||||||||||||
Andya Primanda Inactive Member |
'Therapsids are paraphyletic'
Oh, stupid me. Of course therapsids ARE paraphyletic. If they are to be monophyletic, therapsids should include their descendants the mammals! Glad you noticed that first! *you wouldn't be confusing paraphyletic with polyphyletic, would you?*
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Quetzal Member (Idle past 5902 days) Posts: 3228 Joined: |
quote: Never said there was. The question Delshad posed was "how could placental mammals develop from egg-laying reptiles?" or words to that effect. The theriodont to eutherian sequence I gave was not intended as an evolutionary chain of descent, rather as a sequence showing how "advanced" forms of reproduction can be derived from more "primitive" forms. Comparing anatomy, physiology, and developmental biology between the three branches of the mammalian tree - using modern organisms - starting with the relatively primitive monotremes, passing through the marsupials, and on to the highly derived placentals, there is a definite "shading" in their systems. Since you asked so nicely: Living monotremes share a number of skeletal affinities with reptiles that are not found in other mammals (for instance, a septomaxillae bone, a lizard-like shoulder, and details of the dentition). This indicates that monotreme clade branched off the main mammalian stem more basally than did the other two. The earliest known "true" monotreme is Steropodon, whose classification is primarily based on teeth/jaw structure. All monotremes lay eggs, but platypus incubate them in a nest while echidna incubate them in a pouch. Sounds sort of marsupial-like, doesn't it? Wouldn't take much of a stretch to go from incubating an egg in a pouch to protecting a neonate in a pouch. Especially since the most primitive marsupials alive today (Didelphia) still create a soft-shelled egg - with yolk! - inside the mother before the practically embryonic neonate emerges to finish development in a pouch. The base of the marsupial/placental split is pretty arbitrary. For example, paleontologists classify Eomaia scansoria as the first "true" placental. However, it retains a number of characteristics like its marsupial bretheren. For example, it has epipubic bones extending forward from its pelvis, and a narrow pelvic outlet which suggest that a short gestation period was followed by parental nurture of the young suspended from the abdomen. The earliest "true" marsupial (from around the same time period) has been suggested as Deltatheridium pretrituberculare. The only reason it's classed as a marsupial rather than placental is tooth replacement pattern (it replaces only three molars, rather than the full set normal in the placentals). All three mammal lineages probably originally derived from one of the Morganucodontidae. Which one remains an open question (and in fact as does the actual location of Morganucodon itself). The theriodonts at the very base of the tree are fairly evenly split between the generic "mammal" and "reptile" classifications. It's often dependent on a single bone when you reach this point as to whether the organism is classed as one or the other. Since all of those critters are extinct (three complete families), which one goes where is pretty moot. However, what IS firmly established is that the Theria form a monophyletic clade. Hope this clarifies my response to Delshad.
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Quetzal Member (Idle past 5902 days) Posts: 3228 Joined: |
quote: Speaking of which... It's unlikely you'll find me responding in the fashion you accuse me of - even to you. BTW: Thanks for the support, Adminnemooseus. ----------Note from Adminnemooseus: Barts edit at the end of message 22: quote: [This message has been edited by Adminnemooseus, 10-03-2002]
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Bart007 Inactive Member |
quote: No, I meant "paraphyletic". That is, the Therapsids lack characters that their "presumed" descendants have. The terms "paraphyletic", "polyphyletic", "monophyletic", were invented by evolutionists intent on organizing the data of the fossil record into patterns that look like evolution in their efforts to confirm Neo-Darwinism. As such, they give the illusion of evolution by the very implications of their intelligently assigned meanings. As a creationists, I do not use such terms. I find them and many other definitions used by evolutionists to be rather Orwellian, a newspeak that prevents people (especially students, but the unsuspecting public as well) from thinking in terms other than evolutionary. I was going to write more and answer other posts as well, but am rather tired tonight. O sleep, O gentle sleep, nature's soft nurse! W.S.
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Andya Primanda Inactive Member |
quote: PARAPHYLETIC: In biological taxonomy, a grouping of organisms is said to be paraphyletic if it does not represent all the descendants of some common ancestor. Most schools of taxonomy advocate that groups reflect phylogeny instead, and so view the existence of paraphyletic groups in a classification as errors. Taxonomic groups that do share a common ancestor are called monophyletic.Paraphyly - Wikipedia Therapsids do lack some mammalian characters. That's why not all of them are mammals. Mammals are, phylogenetically, nested within therapsids. Care to discuss about therapsid teeth? They have canines, incisors, etc., differentiated teeth. Mammals are the only other group with differentiated teeth.
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Andya Primanda Inactive Member |
Delshad. You still there?
Care to join me? A guy called Wordswordman just attacked Islam in another thread, and I'm currently taking on him. http://EvC Forum: A listing of the contradictions and errors in the bible. -->EvC Forum: A listing of the contradictions and errors in the bible.
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Tranquility Base Inactive Member |
Andya
Bart very well is trying to point out that a lot of what you think are unbiased facts are actually biased suppositons. Statements of 'paraphylicity' or 'convergent evolution' or 'this fossil was folded in' are rarely facts They are suppositions consistent with the evolutionary framework and do not rule out alternative viewpoints. Within your framework they are highly logical observations and exceptions. [This message has been edited by Tranquility Base, 10-04-2002]
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Bart007 Inactive Member |
quote: Okay, I see where you get your definition for paraphyletic. I won't quiblle about it since, as with most terms used by evolutionists, their definitions are vague, unclear, and/or indeterminate. However, for paraphyletic, the following deifinition may be more exact. "Paraphyletic groups are nothing more than groups of organisms (or subtaxa) that are characterized by the possession of primitive features and the lack of derived features (e.g., Ball, 1975; Eldredge and Cracraft, 1980; Lovtrup, 1973; Nelson and Platnick, 1981)." Schoch RM p 87. (1986) Phylogeny Reconstruction in Paleontology. New York: Van Nostrond Reinhold Co. However, the therapsids are definitely not monophyletic. It is the history and origins (from a comman ancestor) that is the essential point in distinguishing monophyetic groups from paraphyletic groups. There is no known common ancetor for all the Therapsids, and there may never have been one. Have a nice day!
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Minnemooseus Member Posts: 3945 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
quote: I'm saying this from the perspective of one whose biology knowledge is very limited: I think there could be considerable disagreement with that statement. The definitions a probably quite clear and precise. The problem is, is that often these "clear and precise" definitions are "black and white" approximations of what are really "grey area" considerations. Witness the problems of defining the boundries between species. It is really a gradational thing, but still, sharp divisions are defined. That said, I must bring up the very "vague, unclear, and/or indeterminate" definition problem of "kinds". Moose ------------------BS degree, geology, '83; Professor, geology, Whatsamatta U; Old Earth evolution - Yes; Godly creation - Maybe My big page of Creation/Evolution Links [This message has been edited by minnemooseus, 10-05-2002]
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Bart007 Inactive Member |
quote: "Kinds" (i.e. Baramins) is well defined. Its' meaning is identical to the evolutionists term "phylogenetic tree." If you understand the meaning of "phylogenetic tree", then you know what "baramin" means. The difference between evolutionists and creationists is that evolutionists believe there is just one phylogenetic tree ( i.e. a sole baramin, so to speak), Creationists believe there is a forest of these trees, i.e. many Baramins. However, I am not aware of any satisfactory non-vague or determinate definition for "species", do you? [This message has been edited by Bart007, 10-06-2002]
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mark24 Member (Idle past 5226 days) Posts: 3857 From: UK Joined: |
quote: You have defined "baramin", not "kind". If baramin=kind, then phylogeny must=species, right? Of course not. If you had defined "kinds", we could tell them apart? What evidence do you accept in support of baramins, & their associated radiations? Please be specific. Mark ------------------Occam's razor is not for shaving with. [This message has been edited by mark24, 10-06-2002]
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Bart007 Inactive Member |
quote: Baramin = Kind and does not equal species. There can be many species and/or subspecies in a baramin depending on how evolutionsists define "species". Evidence for determining Baramins is the same type of evidence used by evolutionists for determing clades and phylogenies. For both camps it is an ongoing research program.
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Andya Primanda Inactive Member |
So you accept that if several species can be put into a phylogenetic tree, they should be lumped into a baramin?
Fine then, I'll agree with you. Humans and chimps and gorillas have been analysed in many phylogenetic analyses, and they always stay in the same branch on the phylogenetic tree. Therefore we are in the same kind as them, right? I wonder why other creationists say otherwise. I can agree with your definition.
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mark24 Member (Idle past 5226 days) Posts: 3857 From: UK Joined: |
quote: So you agree that birds & mammals are derivatives of reptiles (or amniotes, to give them their correct cladistic name), then? If it's the same evidence, then you wouldn't be tempted to accept one line of evidence because it supported your idea, but reject evidence of the same quality that shows relatedness that goes beyond the family level, would you? Of course not, what am I suggesting?!
[QUOTE]Originally posted by Bart007:
[B] For both camps it is an ongoing research program. [/QUOTE] [/B] For baraminology it is an exercise in hypocricy. Phylogenetics already have multiple phylogenies which clearly show, in a congruent fashion, the relationships between higher taxa. Baraminology will also have this data, but will ignore it. What a wonderful way of getting at the truth! Accept any data that supports your position, & reject the rest..... Mark ------------------Occam's razor is not for shaving with.
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derwood Member (Idle past 1906 days) Posts: 1457 Joined: |
[QUOTE]Originally posted by Bart007:
"Kinds" (i.e. Baramins) is well defined. Its' meaning is identical to the evolutionists term "phylogenetic tree." If you understand the meaning of "phylogenetic tree", then you know what "baramin" means. The difference between evolutionists and creationists is that evolutionists believe there is just one phylogenetic tree ( i.e. a sole baramin, so to speak), Creationists believe there is a forest of these trees, i.e. many Baramins. However, I am not aware of any satisfactory non-vague or determinate definition for "species", do you?[/B][/QUOTE] Speaking of Orwellian... Sorry, Bart, no matter how many times you want to say it, 'kinds' is not well defined. In fact, it is not defined at all. At best, you can get a creationist to say that it is somewhere around the same thing as a Linnaean Family. "Kinds" has no bearing whatsoever on the term "Phylogentic tree." I suggest that you read up on actual creation 'science' before you try to 'teach' others about it, in the usual creationist condescending way. I will gladly discuss baraminology with you. It is one of the big creationist shams and a clear indication of the shoddy 'science' getting churned out by religious fanatics. As for a definition of species, does it not stand to reason that if there were discreet created 'kinds' that such a definiton should be self-evident? The fact that such a definition is elusive is in itself supportive of evolution!
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