Mokele Posted March 28, 2005 Posted March 28, 2005 First off, yes, reptile RBCs are nucleated. In fact, IIRC, mammals are the only vertebrates without nucleated RBCs. I was wondering, will they be able to determine warm-bloodedness or cold-bloodedness from this? Probably not. The DNA will be too degraded to use, nucleated RBCs tell us nothing since both birds and reptiles have them (and mammals don't), and most of the rest seems to be structural fibers and the like. The O2 loading curve of the hemoglobin might give us an indication of metabolic rate, but a) we don't know if the curve would be the same for mass homeotherms and endotherms and b) it's probably too degraded to tell. For Tyrannosaurus, it'd be interesting, but not too surprising if we did find out it was endotherming. They weren't actually very closely related to prior large theropods like Allosaurus, and were instead more close to birds, small theropods like raptors and troodonts, forming a group of fast-moving, possibly-endothermic-but-maybe-just-high-metabolism-ectotherm dinosaurs called the coelurosaurs. I'm a subscriber, if you give me the citation I can e-mail you the file, if you want, just let me know. I'd be interested to hear your take on it. Was it very recent? I'm a couple of issues behind on my reading (plus I get them a week late since they have to be mailed across the ocean, lol). Ooh, i'd be much obliged, if you could. The article is: Padian, de Ricqles & Horner, "Dinosaurian growth rates and bird origins", Nature 412, 405 - 408 (26 July 2001) Mokele
Auburngirl05 Posted March 28, 2005 Posted March 28, 2005 Ooh' date=' i'd be much obliged, if you could. The article is: Padian, de Ricqles & Horner, "Dinosaurian growth rates and bird origins", Nature 412, 405 - 408 (26 July 2001) Mokele[/quote'] I've got the file downloaded, just let me know where to send it to. If you don't feel like broadcasting your e-mail address, mine is tnangelface@earthlink.net, you can just let me know through that if you want.
Guest Sydsnapsidin Posted April 3, 2005 Posted April 3, 2005 Does anyone know if they've found any DNA? How long would it take them to look for? I wonder how much they've done with the tissue, and when they'll release some of the findings.
Anarchaus Posted April 3, 2005 Posted April 3, 2005 http://www.godandscience.org/youngearth/dinoblood.html Just an interesting link I found that discusses a discovery in 1997 that sounds remarkably similar to the story being reported. In that case the scientists found heme not hemoglobin, i read the reports from the scientists themselves, the YEC's did turn that into propaganda, you can find this at many YEC webpages. Heme lasts wayyyyy longer than hemoglobin and is more stable, the YEC took that discovery way out of hand(to suit their purposes no less).
Guest MARCHESI Posted April 4, 2005 Posted April 4, 2005 It 'may' be possible to have a fossilised imprint of the cellular structure, but that is not the same as having 'preserved' cellular structure. A foosil is an imprint, minerals have replaced the original compounds, and these minerals have survived over millions of years. A fossil is not the original material, it is an imprint. Therefore it will not contain DNA.
blike Posted April 4, 2005 Author Posted April 4, 2005 Does anyone know if they've found any DNA? How long would it take them to look for? I wonder how much they've done with the tissue, and when they'll release some of the findings.It will probably be awhile. But here's the initial release: Schweitzer M. H., Wittmeyer J. L., Horner J. R. & Toporski J. K. et al. Science,307. 1952 - 1955 (2005). | Article | PubMed | ChemPort |
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