Episode #146

News Items

    T-Rex Proteins

    • hi guys (and Rebecca),I just heard the latest 5×5 podcast on my drive in, where you discuss the new paper in Science reporting that T. rex is closer to birds than to reptiles.’Very very cool,’ said Steve to close the podcast.Unfortunately, the paper is very, very wrong.The first thing to notice is that the authors of this new paper don’t present *any* new data on T. rex. The only new proteins they looked at were from alligator and ostrichs. The T. rex protein – collagen – was reported in a paper by the same authors one year ago. (As an aside, these guys are doing a remarkable job of getting two Science papers from one small data sample.)That paper a year ago (Science 13 April 2007) reported 7 small protein fragments from collagen in T. rex. The problem is, their interpretation of the data was fundamentally flawed. Multiple experts have re-examined the data – skeptically! – and found that the mass spectrometry data could just as easily be interpreted as bacterial protein fragments. This is far more likely, too – it seems virtually impossible that proteins would survive for >65 million years, and in this case skepticism is warranted.A colleague of mine has a paper under review that demonstrates why all 7 fragments are bogus. I can’t discuss his paper yet – though he says he’s willing to be interviewed by you guys after it is published – but there is already good evidence that the T. rex story – appealing though it is – is falling apart.Notably, in Science on Jan 4 (here’s the link:www.sciencemag.org/cgi/content/full/sci;319/5859/33c )a technical comment was published by Buckley et al reported that ‘We used authentication tests developed for ancient DNA to evaluate claims by Asara et al. (Reports, 13 April 2007, p. 280) of collagen peptide sequences recovered from mastodon and Tyrannosaurus rex fossils. Although the mastodon samples pass these tests, absence of amino acid composition data, lack of evidence for peptide deamidation, and association of {alpha}1(I) collagen sequences with amphibians rather than birds suggest that T. rex does not.’In addition, the authors themselves already retracted one of their 7 claimed fragments – see Science letters, 7 Sept 2007. They wrote the letter as a ‘reinterpretation’ but it really is a correction.So although T. rex is probably closer to birds than to reptiles, this particular paper is wrong. We’d like to believe it but it doesn’t appear that soft tissue retained any T. rex proteins.-Steven SalzbergUSA
    • The UK-sceptics forum has been discussing the Water experiment theintentionexperiment.ning.com/profiles/blog/show?id=848178%3ABlogPost%3A94693 taking place today.Looks to me like a well designed experiment so that it is non-falsifiable! It might make an interesting news item on the podcast. Graham Lappin

    Science or Fiction

    • Item #1 Science

      Computer models suggest that the solar system moves through the plane of the galaxy every 35 millions years and that this is responsible for mass extinctions.

    • Item #2 Fiction

      New information supports the hypothesis that world-wide forest-fires were primarily responsible for the mass extinction (including the dinosaurs) at the end of the cretaceous.

    • Item #3 Science

      A recent genetic analysis shows that the duck-billed platypus shares some genetic features in common with birds rather than other mammals.

    Skeptical Quote of the Week.