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Why the Tasmanian tiger went extinct – new insights

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thylacine/University of Adelaide

It’s one of those situations where everything we knew about the tiger’s (thylacine wolf’s) extinction is true, but some new information rounds out the picture.

From “Tasmanian Tiger’s Jaw Was Too Small to Attack Sheep, Study Shows” (ScienceDaily, Aug. 31, 2011), we learn:

Australia’s iconic thylacine, or Tasmanian tiger, was hunted to death in the early Twentieth century for allegedly killing sheep; however, a new study published in the Zoological Society of London’s Journal of Zoology has found that the tiger had such weak jaws that its prey was probably no larger than a possum.

“Our research has shown that its rather feeble jaw restricted it to catching smaller, more agile prey,” said lead author Marie Attard, of the University of New South Wales Computational Biomechanics Research Group. “That’s an unusual trait for a large predator like that, considering its substantial 30 kg body mass and carnivorous diet. As for its supposed ability to take prey as large as sheep, our findings suggest that its reputation was at best overblown.

The weak jaw fills in a hole, certainly, in accounting for the marsupial wolf’s extinction. Had the wolf been able to kill sheep easily, it might not have gone extinct. Human persecution can greatly limit a well-adapted animal’s numbers and range without extinguishing it.

Using advanced computer modelling techniques, the UNSW research team were able to simulate various predatory behaviours, including biting, tearing and pulling, to predict patterns of stress in the skull of a thylacine and those of Australasia’s two largest remaining marsupial carnivores, the Tasmanian devil and the spotted-tailed quoll

“By comparing the skull performance of the extinct thylacine with those of closely related, living species we can predict the likely body size of its prey,” says the director of the Computational Biomechanics Research Group, Dr Stephen Wroe. “We can be pretty sure that thylacines were competing with other marsupial carnivores to prey on smaller mammals, such as bandicoots, wallabies and possums.

red white areas in thylacine skull right reveal weakness, in digital stress tests/Marie Attard

Another problem was the introduced wild dog or dingo, that was better adapted to killing large prey. The last known thylacine died in a Hobart zoo in 1936, though some are convinced that surviving thylacines may be found.

See also: Extinction: Limited genetic diversity may not doom Iberian lynx after all

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DrREC, are you arguing Theology to try to make your case for Darwinian 'convergent' evolution????,,, Despite DrREC's deep personal issues with Theology and his propensity to argue Theology instead of science when his position is weak, convergent evolution, as an 'excuse' for Darwinian evolution, is now severely compromised by the scientific evidence we have in hand;
Lenski's Citrate E-Coli - Disproof of Convergent Evolution - Fazale Rana - video (the disproof of convergence starts at the 2:45 minute mark of the video) http://www.metacafe.com/watch/4564682 The Long Term Evolution Experiment - Analysis Excerpt: The experiment just goes to show that even with historical contingency and extreme selection pressure, the probability of random mutations causing even a tiny evolutionary improvement in digestion is, in the words of the researchers who did the experiment, “extremely low.” Therefore, it can’t be the explanation for the origin and varieity of all the forms of life on Earth. http://www.scienceagainstevolution.org/v12i11f.htm The loss of 'convergent evolution', as a argument for molecular sequence similarity, is a major blow to neo-Darwinian story telling: Implications of Genetic Convergent Evolution for Common Descent - Casey Luskin - Sept. 2010 Excerpt: When building evolutionary trees, evolutionists assume that functional genetic similarity is the result of inheritance from a common ancestor. Except for when it isn't. And when the data doesn't fit their assumptions, evolutionists explain it away as the result of "convergence." Using this methodology, one can explain virtually any dataset. Is there a way to falsify common descent, even in the face of convergent genetic similarity? If convergent genetic evolution is common, how does one know if their tree is based upon homologous sequences or convergent ones? Critics like me see the logic underlying evolutionary trees to be methodologically inconsistent, unpersuasive, and ultimately arbitrary. http://www.evolutionnews.org/2010/09/implications_of_genetic_conver037841.html Origin of Hemoglobins: A Repeated Problem for Biological Evolution - 2010 Excerpt: When analyzed from an evolutionary perspective, it appears as if the hemoglobins originated independently in jawless vertebrates and jawed vertebrates.,,, This result fits awkwardly within the evolutionary framework. It also contradicts the results of the Long-term Experimental Evolution (LTEE; Lenski) study, which demonstrated that microevolutionary biochemical changes are historically contingent. http://www.reasons.org/origin-hemoglobins-repeated-problem-biological-evolution Moreover, identical forms of echolocation show up in widely divergent species. This finding is unexpected from an evolutionary perspective, yet this finding is exactly what we would expect to find from presupposing a Creator to reuse optimal designs: Convergence Drives Evolution Batty - Fazale Rana - September 2010 Excerpt: The multiple, independent origin of echolocation in these animals (twice in bats and once in toothed whales) exemplifies convergence,,, When examined from an evolutionary perspective, convergence doesn’t make much sense.,,, the latest research demonstrates,,, the genetic and biochemical changes that account for the emergence of echolocation in bats and dolphins is identical. Given the random nature of the evolutionary process, this recent discovery doesn’t match what evolutionary biologists would expect to find. But both the discovery and convergence make sense if life stems from the work of a Creator. http://www.reasons.org/convergence-drives-evolution-batty Common Design in Bat and Whale Echolocation Genes? - January 2011 http://www.evolutionnews.org/2011/01/common_design_in_bat_and_whale042291.html Bat and Whale Echolocation Genes Point to Common Design - February 2011 - Podcast http://intelligentdesign.podomatic.com/entry/2011-02-21T10_59_16-08_00 Convergence: Evidence for a Single Creator - Fazale Rana Excerpt: When critically assessed, the evolutionary paradigm is found to be woefully inadequate when accounting for all the facets of biological convergence. On the other hand, biological convergence is readily explained by an origins model that evokes a single Creator (reusing optimal designs). http://www.reasons.org/convergence-evidence-single-creator Lenski's work also conforms to the extreme limit found for just two 'coordinated' mutations conferring any 'evolutionary benefit'; Michael Behe on the most recent Richard Lenski “evolvability” paper - April 2011 https://uncommondesc.wpengine.com/irreducible-complexity/michael-behe-on-the-most-recent-richard-lenski-%E2%80%9Cevolvability%E2%80%9D-paper/
It is only minor differences dealing with reproduction or skeleton that easily are concluded to be adaptations upon migration to some areas. I see marsupialism as simply a increase in production in the areas farthest from the ark. Australia and South america. If the morphology of a creature is dead on with another creature then its the same creature since morphology determines relationship. A marsupial wolf is identical to our wolves/foxes and the first conclusion should be its all one group. Not invoking unlikely concepts of convergent evolution to explain thousands of points of like anatomy. Simply explain the few different ones. When Australia was discovered the fauna was not what it had been originally because of extinction. if they had seen the marsupial lions, wolves, tapirs, rats, etc they probably would of said it was the same creatures as elsewhere on earth with local variation. TYet they were deceived by just seeing strange kangaroos, koalas, etc that were not seen elsewhere. Its been a great classification humbug. Robert Byers
In order to have them go extinct a few thousand years later? DrREC
A pouch, a different weaker jaw, mitochondrial DNA sequences that do not align with canines, but rather other marsupials. I know the photo of a thylacine next to a reproduction of a that same photo flipped and desaturated is some compelling evidence, but maybe you should move beyond that little bit of fakery. http://austringer.net/wp/index.php/2007/01/26/cornelius-g-hunter-thylacines-wolves-and-images/ Besides that, what compels you to group them with canines? And what is the YEC/ID story here? Canines got off the Ark, God saw they needed a pouch and weak Jaw, and scrambled mitochondrial DNA that makes them look like marsupials, and made it so? DrREC
The ranchers thought it was killing shhep because it acted like a wolf or fox. Theres always the attempt to say creatures were not harmful because they were exterminated. The more important point here for creationism is that the marsupial wolf was a canine. its pouch and a few other details has wrongly put it into a special marsupial group. marsupials were just placentals with minor area adaptation. One can google it in still and moving pictures and it will be seen to walk, sit, stare just like and dog. It is not a modified kangaroo as evolutionists suggest. Yes it also howled at midnight. The marsupial wolf, lion, mouse, tapir, etc etc are just what they are despite having pouches. They are not the result of impossible and unneeded ideas of convergent evolution. Therefore the seeming aberration of a exclusive marsupial fauna in australia and not elsewhere TODAY can easily be explained as just a ordinary result of animal migrations across earth, from the ark if i may say so, in the earkly days. Marsupialism probably a mere need for better production. Likewise many creatures are put into segregated orders of animals despite dead on looks with other creatures in other orders. The classification system has been wrong and another wrong idea of evolutionary thought. Robert Byers

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