Archive for May, 2009
ANALYSIS OF COMPLETE MITOCHONDRIAL GENOMES FROM EXTINCT AND EXTANT RHINOCEROSES REVEALS LACK OF PHYLOGENETIC RESOLUTION – Eske Willerslev, Marcus Gilbert, Jonas Binladen, Simon Ho, Paula Campos, Aakrosh Ratan, Lynn Tomsho, Rute da Fonseca, Andrei Sher, Tatanya Kuznetsova, Malgosia Nowak-Kemp, Terri Roth, Webb Miller and Stephan Schuster
Amidst the recent outcry over phylogenetic hype, it is nice to see some truth in advertising. Sure one might quibble over whether the lack of a pattern is something that can be “revealed” but microecos never quibbles over semantics…
Semantics aside, what is tremendously cool about this paper is the recovery of mitochondrial genes from preserved soft tissues of the extinct woolly rhino, Coelodonta antiquitatis. Despite the overall lack of resolution among the clade, Willerslev and company recover strongly supported sister relationships between the two African rhinos (the white rhino, Ceratotherium simum and the black rhino, Diceros bicornis) and between the congeneric Javan and Indian rhinos (Rhinoceros sondaicus, R. unicornis).
While neither of these relationships are surprising, the authors also found support for a sister relationship between the woolly rhino and the ridiculously adorable, critically endangered Sumatran rhino (Dicerorhinus sumatrensis). This relationship has been postulated before, at least partly based on the fact that Dicerorhinus is unique among living rhinos in sporting luscious, auburn locks that put agent Scully to shame. However, this hypothesis has been controversial and this new paper certainly leaves the door open for considerable improvement in our understanding of the evolutionary history of living rhinos.
One of the problems here is that today we are left with only a tattered remnant of the great perissodactyl radiation that produced some of the most impressive, perplexing and yes (ahem) EXTREME mammals that have ever existed. Aside from the four rhino genera, a handful of tapirs (all in genus Tapirus) and a rather more respectable smattering of zebras, asses and kiangs (in the familiar, but rather lumpy genus Equus) are all that remains of this once diverse order. In the recent analysis, relationships amongst the rhino couplets changed dramatically depending on whether tapirs or horses were used as the out-group, perhaps indicating a geologically explosive radiation of rhinos from their perissodactyl ancestors at some point in the Cenzoic.
Sadly, we stand to lose even more of this evolutionary majesty if the poaching and deforestation that imperil all living rhinos isn’t checked. While the recovery of genetic material from the extinct woolly rhino is a remarkable achievement, it would be terribly tragic if scraps of keratin are all that future studies of rhino evolution have to go on.
But I hate to leave you on such a bitter note, so behold, the otherworldly wonder that is a baby Sumatran rhino:
I once wrote a paper entitled “Applying the Principles of Stratigraphy in an Analysis of Melodrama.” Sadly, this was long before There Will Be Blood came out.
This video by Grizzly Bear reminds me of that paper, for several reasons, but, I’ll spare you the golemy details. I dig the layers of metaphor though, puns possibly not intended.
Anyone recognize the location? Anza Borrego or something? And presumably those flags in the first scene are a paleo site right?
Props to Radov for leading me, indirectly, to this video.
Last time, we looked at various portraits of a weak-ass minor planet getting effed up by our atmosphere before getting royally bitch slapped by our lithosphere. Anyone with a passing interest in dinosaurs will know that strike of the space-junk, while widely accepted (though see recent meso-profile critiques), is but one of countless etiologies proposed for terminal Cretaceous bummer days.
You might think that protracted catastrophes like pestilence, climate change and famine offer less in the way of dramatic potential than a body of a certain mass rapidly attempting to occupy the same space as a much more massive body. If so, you should probably read more.
At all points the dinosaurs that had trampled the earth till the grasses grew, the most superb of all vertebrates, the creatures that fix the imagination above all others, are seen to fail. The growth forces and the responses to environment were no longer in adjustment. Eggs were few, their loss from attack devastating, life slow. The young were the prey of their own kind, and the race had lived long enough for reptiles lower in life’s scale to threaten. If new enemies were needed they were at the jungle-edge. Geologic change that once would have meant mere fluctuation in habitat affected the declining numbers disastrously, and what such change and the reptiles soon to rule in the forests of the Eocence may have failed to accomplish, senility did. That long dinosaurian day was done. Its sun was sinking beneath the horizon forever. (Wieland 1925).
15 years later Disney took a stab, note that it anticipated Bataan by at least a year. Talk about zeitgeist. While drought and desertification deal the fatal blow (with some help from miring), major geologic upheaval kicks in as an epilogue. We can talk about this and Lyell, and Agassiz some time.
Now, assuming you are are as sick of asteroid porn and dinosaurs as I am you will want to hear about the mass dysphoria induced by Stravinsky’s Rite of Spring courtesy of radio lab.