September 2, 2014
A couple of weeks ago, more than hundred scientists sent an open letter to the AAAS (American Association for the Advancement of Science) about their new open-access journal Science Advances, which is deficient in various ways — not least the absurdly inflated article-processing charge.
Today I learn from email that there has finally been a response — of sorts. Editor-in-Chief Marcia McNutt had a long phone-call with Jon Tennant — one of the hundred-plus authors/co-signers. All we know about that call is (and I quote from Jon’s email account) “it became quite apparent that we would have to agree to disagree on many points”.
All I want to say is this. When a hundred scientists co-sign an open letter, it is TOTALLY UNACCEPTABLE for the response to take the form of a private telephone call with one of those authors.
Come on, AAAS. This is all about openness. Let’s see an open response: a substantive, non-patronising one which addresses the actual points made in the original letter.
Meanwhile, you may like to read this article at The New Statesman: Scientists criticise new “open access” journal which limits research-sharing with copyright. In finishes on this very clear note, courtesy of Jon Tennant:
The AAAS should be a shining beacon within the academic world for progression of science. If this is their best shot at that, it’s an absolute disaster at the start on all levels. What publishers need to remember is that the academic community is not here to serve them – it is the other way around.
August 28, 2014
I’m scrambling to get everything done before I leave for England and SVPCA this weekend, so no time for a substantive post. Instead, some goodies from old papers I’ve been reading. Explanations will have to come in the comments, if at all.
For more noodling about nerves, please see:
- The world’s longest cells? Speculations on the nervous systems of sauropods
- Oblivious sauropods being eaten
- Butler, A.B., and Hodos, W. 1996. Comparative Vertebrate Neuroanatomy: Evolution and Adaptation. 514 pp. Wiley–Liss, New York.
- Nieuwenhuys, R. (1964). Comparative anatomy of the spinal cord. Progress in Brain Research, 11, 1-57.
- Streeter, G. L. (1904). The structure of the spinal cord of the ostrich. American Journal of Anatomy, 3(1), 1-27.
July 4, 2014
You may know that the inaugral TetZooCon is set to take place next Saturday (12 July) at the London Wetland Centre. It’s an informal convention that’s condensed around occasional SV-POW!sketeer Darren Naish’s absurdly informative blog Tetrapod Zoology, and features a day of talks, a palaeoart workshop and a quiz. At £40 for the day, it’s a bit of a bargain.
Among the speakers is my own good self, and I will be talking about why giraffes are rubbish.
If that sounds like your idea of a good time, then you need to move fast! Booking closes at 4pm this evening. Better get on it now!
June 9, 2014
We’ve touched on this several times in various posts and comment threads, but it’s worth taking a moment to think in detail about the various published mass estimates for the single specimen BM.R.2181 (formerly known as HMN SII), the paralectotype of Giraffatitan brancai, which is the basis of the awesome mounted skeleton in Berlin.
Here is the table of published estimates from my 2010 sauropod-history paper, augmented with the two more recent estimates extrapolated from limb-bone measurements:
|Author and date||Method||Volume (l)||Density (kg/l)||Mass (kg)|
|Janensch (1938)||Not specified||–||–||`40 t’|
|Colbert (1962)||Displacement of sand||86,953||0.9||78,258|
|Russell et al. (1980)||Limb-bone allometry||–||–||13,618|
|Anderson et al. (1985)||Limb-bone allometry||–||–||29,000|
|Paul (1988)||Displacement of water||36,585||0.861||31,500|
|Alexander (1989)||Weighing in air and water||46,600||1.0||46,600|
|Gunga et al. (1995)||Computer model||74,420||1.0||74,420|
|Christiansen (1997)||Weighing in air and water||41,556||0.9||37,400|
|Henderson (2004)||Computer model||32,398||0.796||25,789|
|Henderson (2006)||Computer model||–||–||25,922|
|Gunga et al. (2008)||Computer model||47,600||0.8||38,000|
|Taylor (2009)||Graphic double integration||29,171||0.8||23,337|
|Campione and Evans (2012)||Limb-bone allometry||–||–||35,780|
|Benson et al. (2014)||Limb-bone allometry||–||–||34,000|
(The estimate of Russell et al. (1980) is sometimes reported as 14900 kg. However, they report their estimate only as “14.9 t”; and since they also cite “the generally accepted figure of 85 tons”, which can only be a reference to Colbert (1962)”, we must assume that Russell et al. were using US tons throughout.)
The first thing to notice is that there is no very clear trend through time, either upwards or downwards. Here’s a plot of mass (y-axis) against year of estimate (x-axis):
I’ve not even tried to put a regression line through this: the outliers are so extreme they’d render it pretty much useless.
In fact, the lowest and highest estimates differ by a factor of 5.75, which is plainly absurd.
But we can go some way to fixing this by discarding the outliers. We can dump Colbert (1962) and Alexander (1989) as they used overweight toys as their references. We more or less have to dump Russell et al. (1980) simply because it’s impossible to take seriously. (Yes, this is the argument from personal incredulity, and I don’t feel good about it; but as Pual (1988) put it, “so little flesh simply cannot be stretched over the animal’s great frame”.) And we can ignore Gunga et al. (1995) because it used circular conic sections — a bug fixed by Gunga et al. (2008) by using elliptical sections.
With these four unpalatable outliers discarded, our highest and lowest estimates are those of Gunga et al. (2008) at 38,000 kg and Taylor (2009)at 23,337. The former should be taken seriously as it was done using photogrammetrical measurements of the actual skeletal mount. And so should the latter because Hurlburt (1999) showed that GDI is generally the least inaccurate of our mass-estimation techniques. That still gives us a factor of 1.63. That’s the difference between a lightweight 66 kg man and and overweight 108 kg.
Here’s another way of thinking about that 1.63 factor. Assuming two people are the same height, one of them weighing 1.62 times as much as the other means he has to be 1.28 times as wide and deep as the first (1.28^2 = 1.63). Here is a man next to his 1.28-times-as-wide equivalent:
I would call that a very noticeable difference. You wouldn’t expect someone estimating the mass of one of these men to come up with that of the other.
So what’s going on here? I truly don’t know. We are, let’s not forget, dealing with a complete skeletal mount here, one of the very best sauropod specimens in the world, which has been extensively studied for a century. Yet even within the last six years, we’re getting masses that vary by as much as the two dudes above.
Remember how my better half, Dr. Vicki Wedel, edited a book about blunt force trauma, called Broken Bones?
If you live in SoCal and you’d like to get a copy, or get your copy signed, then you’re in luck. Vicki will be one of a dozen local authors signing books at the San Bernardino County Museum this coming Sunday, May 18. There will be books for sale if you don’t yet own the titles you want. Noted paleontologist and skeptic Don Prothero will be giving the keynote address and signing copies of his new book, Reality Check. If you’re in the area, come on by. Details here: