Marsupial evolution

Though marsupial stripes are sort of on topic they aren't the core of the discussion here which concerns the similarities between placentals and marsupials.Do not go running down yet another rabbit hole asking questions to which the answers are obvious and not on topic.

evolutionary biologists can easily tell, yes. oh, that's cheating. the ventral views with the palatial holes are a dead give away! if it's got them, it's marsupial. that's a rather easy rule to remember. the fact that students fails tests has no bearing on the facts. in fact, they fail because they get the facts wrong. i've failed a paleo test before too, you know. heck, my professor didn't even mark me down when i mixed up a dalmanites with a ptychopariid trilobite (cause my drawing of the geesops one ROCKED). does that mean a qualified paleontologist can't tell the difference between a dalmanites and a ptychopariid? heck no. of course they can. they look similar to the untrained eye, but that's why it's called "the untrained eye."people who specialize in things know more than your average student, or ignorant bystander. but the bystander's ignorance is not the fact -- the expert's knowledge is. and those palatial holes and dental forumalae ARE significant. feel free to compare to the above. i see 2 molars, 4 premolars, and a carnassial tooth on top, 3 molars and 4 premolars on the bottom. i see no palatial holes. lacrimal bone visible from side. the joint between the upper and lower jaws looks like a placental one. i see pinched nasals. the cheek bone's suture looks like a placental one.the whole, it looks a lot like the dog of the wolf, but NOT the tasmanian "wolf" that looks more like the kangaroo. sorry, you're still wrong. try again. if by "strikingly" you mean "not at all." yes, the platypus was clearly sewn together as a joke amongst biologists. haha funny stuff that. cats have stripes too. lots of things have stripes. coloration patterns come and go very quickly evolutionarily speaking. look at all the different breeds of dogs -- all the same species. how an animal is colored is actually irrelevent. things like osteology (as above) are much, much more important. maybe not as obvious to someone who doesn't know anything about biology, but important nonetheless.

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Martin is referring to a very rare duiker of Sierra LeoneWhich indeed has a similar pattern like Thylacine except it covers the majority of its body.The page cannot be foundOh and in addition I found another marsupial with similar markings accented towards the back. How and why the observation that animals within the Class Mammalia have similar markings destroys Evolutionary theory is still a mystery.

Stripes as discussed here are not on topic. So I decree.

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Though marsupial stripes are sort of on topic they aren't the core of the discussion here which concerns the similarities between placentals and marsupials.

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Coloration and shape of animals is what counts. No animal except man compare skulls of differnet species. No wild animal - as far as I know - is interested in dissecting anatomy of other animals. What other animals are interested of are predominantly these - shape, color, smell, taste.I wanted to discuss how different animals perceive each other and if such perception could lead to natural or sexual selection.The problem of underlying molecular biology is unimportant even if some guys here consider it as crucial. It is as unimportant as it is what is behind scenes when you look in theatre to a play. It could not help you underestand better what you see on the stage if you know what is behind stage. Yet I have no knowledge of experiment supporting darwinistic hypothesis of function of stripes as "camouflage" ("it is at least plausible without any experiment"). Again see my post 226.I - personaly - see no obvious answer of function of stripes on back of marsupial wolf - placental wolf do not have such stripes as far as I know.Anyway I agree this is the topic for itself. It would be pity if I would be banned because of my remarks of coloration and stripes. The same problems occured discussing coloration of mushroom on the thread about mammals - the thread was closed.Maybe it would be fine to open new thread about coloration of animals and explanation of it. Is it possible?

The topic IS the comparison of marsupial and placental animals!If you bring this same thing up here or in any other thread you'll get a time out. There will be no further warnings.It is, of course, perfectly fine to open another thread on the coloration or stripes topic. I suggest you do so and, unless you have something to contribute, stay out of this one.

The North American Wolf and dog share more similarities with the Thylacine than they do with Kangaroos. Just as much could be said of the disimilarities than they could the similarities. Marsupials are still an anamoly, which makes traditional taxonomy weaker than clades, IMO.

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"God is like the sun. You can't look at it. But without it you can't look at anything else." -G.K. Chesterton

nosy, it's a superficial difference: the kind of things creationists bring up saying "look at this marsupial that looks like a placental," as contrasted with the more important skeletal and genetic differences. it certainly seems on-topic, as the topic is "looks similar" vs. "is related."

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no, they don't. the thylacine skull and body plan may look vaguely dog-like to you, but it's not any closer to a dog than a kangaroo is. both come from smaller marsupials that you'd mix up with placental rodents. it's simply convergence, and we know it's convergence because the details are more similar to other marsupials than to placentals. of course. they're still mammals, which means they're still therapsids. the evolutionary tree is organized (partly) on the basis of apomorphy and plesiomorphy. since the features that group a thylacine together with a dog are much more basal general features, their common ancestor is lower on the tree. whereas the features that goup it together with a kangaroo are very specific, and so they divide higher on the tree. marsupials (metatheria) aren't really an anomaly. they are a half-way point between laying eggs (monotrema) and full live birth (eutheria).Edited by arachnophilia, : typo

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No they do not! The method of giving birth is a *major* internal bodily function modification that also requires in additional commensurate behavioral modifications.The Thylacine share attributes of other marsupials. For example at this reference:http://www.naturalworlds.org/...turalhistory/behaviour_1.htmThere are two images of Thylacine in a kangaroo like pose, standing upright resting on its elongated back feet and even using the end of its very stiff tail for support. Further the Thylacine as known to a powerful jumper.Edited by iceage, : No reason given.

I do not believe that analogy has any justification or provides any insight. The back stage does not influence the substance of a play in a significant way. However, it may help to understand a play by understanding the person wrote the play - that would be more appropriate.Back to the molecular how...Recently I was reading an essay by Gould on Male Nipples when he commented that Francis Crick once responded to Gould's strong functionalist (everything must have a purpose) bias with the comment (paraphased from memory)
"Why do biologist always try to understand the value of an attribute *before* you understand the underlying molecular how" Edited by iceage, : No reason given.

Aren't dogs and wolves the same species essentially? They can interbreed. Seems a bit suspect then to claim because dogs and wolves are more similar than a marsupial wolf, that somehow a real point is being made?Aren't members of the same species or at least so close they can breed together suppossed to be more similar than a different species altogether?

Okay, then let's say that wolves and bears are more similar than wolves and the thylacine ...Bear:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Ursidae
Genus: Ursus
Species: U. arctosWolf:
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Canidae
Genus: Canis
Species: C. lupusthylacine
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Dasyuromorphia
Family: Thylacinidae
Genus: Thylacinus
Species: T. cynocephalusThe thylacine is also called either the Tasmanian Tiger or the Tasmanian Wolf, so does that mean it is related to both tigers and wolves? Or is the similarity of thylacine to tigers just superficial while the similarity of thylacine to wolves isn't?The skull is different, the teeth are different, the reproductive system is different, and in each case MORE different from the wolf than the wolf is from the bear.Enjoy.Edited by RAZD, : .

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You are picking and choosing what to compare. Of course, the reproductive system is different as it is for all Marsupials compared to placentals. The point is everything BUT the reproductive system.Edited by randman, : No reason given.

Except that this too is false.As noted the skulls and teeth are different, they are more different between thylacine and wolf than between wolf and bear. There are others that are less visible to the layman, but which are significant to the taxonomist.In the Dogs will be Dogs thread (correct me if I am wrong) you welcomed my use of variation within the dog species as a metric to measure evolution, and thought it was about time somebody came up with something like that. What you don't know is the depth of measurements that taxonomists make of every fossil to quantify the similarities and differences.http://www.archaeologyinfo.com/er1813.htm

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KNM-ER 1813

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A relatively complete cranium of an early Homo lacking part of the left side of the face. It has been designated a Homo Habilis with a smallish cranial volume of 505 to 510 ml. The postorbital constriction is moderate. The nuchal crests are weak and the mastoid process is small. This early Homo specimen was found below the KBS tuff. It was within a deposit that reflects either a delta plain or shallow, offshore lake environment.

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Bold for emphasis on the comparison terminology, and note that these are not things subject to change during development of an individual, but critical small differences in one group of fossil from another -- differences much smaller, btw, than those known to exist in dogs. I am pointing out things that are readily visible as different to those who are interested in seeing the differences rather than gloss over them.Of course there are things that are similar between thylacine and wolf and bear, but there are also many things that are similar to reptiles. And the degrees of similarity correspond to the dates for last common ancestorsEnjoy.Edited by RAZD, : addedEdited by RAZD, : .

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we are limited in our ability to understand
by our ability to understand
Rebel American Zen Deist
... to learn ... to think ... to live ... to laugh ...
to share.

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