Archive for November, 2008
POSTSCRIPTO- Unintentionally appropos: Daruka, I (2008) A phenomenological model for the collective landing of bird flocks. Proceedings of the Royal Society, B DOI: 10.1098/rspb.2008.1444.
Abstract: A three-dimensional phenomenological model was developed to describe the collective landing of bird flocks. The employed individual based model included the landscape (as an external field) and a continuous internal variable G, to characterize the landing intent of the birds. The birds’ interaction with the landscape was coupled adaptively to their landing intent. During the flight, a sharp crossover is observed in the dynamics of the landing intent, i.e. from the initial, non-landing state (small G) to the landing state (large G) that was terminated by the landing of the flock. In the model, the landing process appears to be a highly concerted, collective motion of the birds, in agreement with the field observations.
Diatoms are dynamite. They are also deeply rad and, one might say, totally protarded. As a person interested in the evolutionary trajectory of marine ecosystems I follow the diatom evolution beat with great zeal. So I was excited to see this paper pop up in Nature last week.
It’s an interesting paper, documenting exceptionally high rates of genomic evolution among diatoms and pervasive lateral gene transfer from bacteria to the diatom genome, though I must admit that many of the genetic details are above my head. Once sentence (or rather, parenthetical clause) gave me pause however:
The more rapid evolutionary rates of diatoms compared with other organismal groups (for example, the fish–mammal divergence probably occurred in the Proterozoic era earlier than 550 Myr ago) is consistent with previous observations — Bowler and friends (2008)
Uh is it just me, or is that a, er, liberal estimate? The authors cite the Clinton-era classic: Kumar and Hedges 1998 for that divergence date. (You might remember the film adaptation, Kumar and Hedges go to HOVERGEN, where Neil Patrick Harris goes crazy and snorts coke off the electrophoresis tray).
Rereading that paper, it seems that the Bowler and co. are referring to the proposed timing of the Homo/hagfish split. The date they are looking for–the split between sarcopterygians (e.g. Homo) and actinopterygians (e.g. Takifugu)–is probably more like 450 Ma, at least based on Kumar and Hedges (1998), that date may have been updated since then I don’t know. 100 million years might seem like a trivial matter, but you know, 100 million years here or there, and pretty soon you’re talking about real time. In this case, the disparity in genomic evolutionary rates between vertebrates and diatoms is reduced somewhat relative to what the authors report, although their overall point that centric and pennate diatoms have experienced relatively rapid genomic divergence over the past 90 Ma or so holds.
One wonders how a mistake like that (albeit not one of tremendous importance to the central thrust of the paper) slipped past all sexillion authors (seriously, check out the author list), the reviewers and the Nature editorial staff.
Whatever, diatoms are still totally toothpaste bro.
Photo Tony Linck, 1948
Matt from HMNH recently posted some gems from the amazing LIFE photo collection that is going up on Google.
Here are some amazing images filed under “Reptiles.” Each, warrants pages of minor musings, but of course each is worth volumes alone so I’ll spare you. Keep your eye out for gliders in glight and stone, safety-conscious crocodilians, A. S. Romer in a jam, and of course various feats of snake handlin. Happy Hunting!
Photo Ralph Crane, Los Angeles 1972
but they might provide temporary relief. Of course you should always talk to your personal care provider before beginning any treatment program.
Some weeks ago, I wrote about using Google Trends to track natural phenomenon via search term proxy (See: Dust, Wind, Dude). Unsurprisingly, those clever folks at Google were way ahead of me and have recently unveiled Google Flu Trends a tool which tracks flu-related Google searches state-by-state as an index for the intensity of influenza activity.
The potential public health applications and, more amusingly, misapplications of this technique boggle the mind….
Seriously though, can’t they just release Picasa for Mac OS already?