fossil of an aquatic animal

A few years ago, I wrote a post about prediction in the historical sciences. This post came in anticipation of the publication of Tiktaalik roseae, a remarkably well-preserved fossil of an aquatic animal very closely related to the first tetrapods. I offered this figure to illustrate the position of a gap in the fossil record as a predicate for how/where we might look for fossils that would fit within those 'gaps' in phylogeny.

Yesterday, this picture got a lot more complicated. With the publication of tetrapod footprints some 18 million years in advance of this gap by Niedźwiedzki et al., the nice congruence between the node order of the tree and stratigraphy no longer appears so nice.

Here's a picture of the trackways (click for the full view):



[More below the fold]


This news has already broken, and I'm usually the last person to blog about it these days. Naturally, Ed Young has a good take on it. As noted by Jenny Clack in Ed's piece, the individual footprints are more convincing than the trackways in terms of their identity. Here's one from the supplementary information file (which is free to access).

[Picture deleted: I made a mistake, reading too fast and posted an image of Triassic temnospondyl footprints! A better image is this digital surface rendering from the main paper posted below]



But how "bad" is the record now that we know this? Well, bear in mind that lungfishes and tetrapods are considered (at least by the phylogenies in question) to be sister groups. That is, they split from their last common ancestor at exactly the same time. The earliest 'true' lungfishes (i.e. lungfishes with toothplates, and upper jaws fused to the braincase, etc.) are Emsian in age, roughly the same age as these new footprints. Recognizable close relatives of lungfishes, such as Diabolepis, Youngolepis and Powichthys, however, are considerably older. Do, we can set a minimum age for the origin of the tetrapod stem lineage down in very earliest part of the Devonian even if we do not have the fossils.

So, not surprisingly, the record is pretty bad. It's certainly 'gappy'. But we should not be too surprised that tetrapods emerged long before the time when we find their first actual fossils.

the University's statement on the event

I was much dismayed to learn that Ann Coulter was going to speak at the University of Ottawa. I was even more dismayed to find that the U of O provost sent her a letter warning her of the consequences of hate speech. However, I'm shocked and ashamed that her talk has been cancelled citing "security reasons". The real reason seems to be a response to the 2,000 angry protesters on campus. I support the protesters, but I also support Ann Coulter's right to speak—even if I find what she has to say bigoted, vile, and contemptible.

In the first instance, I don't think she should have been invited to speak at the U of O at all. While I'm not a conservative, I grant that there are probably countless other conservatives with far more scholarly and worthwhile opinions than Coulter. Coulter is the Howard Stern of political punditry, and the more shocking and offensive her remarks the more she thrives. After all, each time she spouts one of her racist, homophobic, or xenophobic slurs, her name rockets up to the top of the headlines. There is all of zero intellectual content in what she has to say. Nonetheless, she had been invited to speak and the attempt to un-do the mistake is simply a farce.

On a university campus, the way to handle cases like Ann Coulter is pretty simple: pack the audience and ask questions at the end. The stage is as much a platform for her to speak as it is one for her to receive the brunt of criticism and questioning of her dispicable views. Universities are marketplaces of ideas, and there's no doubt that there are enough well-informed, intelligent people there who can handle Coulter's hateful rhetoric.

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UPDATE: The news now is that it was the organizers themselves, not the university who pulled the plug on this event. Like several other bloggers and columnists, I was quick to pour scorn on the U of O.

Here's the University's statement on the event:

Dear Alumni and Friends,

On Tuesday, March 23, an appearance by Ann Coulter was scheduled on our campus, organized by the International Free Press Society Canada and the Clare Boothe Luce Policy Institute.

The University of Ottawa has always promoted and defended freedom of expression. For that reason, we did not at any time oppose Ann Coulter’s appearance. Whether it is Ann Coulter or any other speaker, diverse views have always been and continue to be welcome on our campus.

Last night, the organizers themselves decided at 7:50 p.m. to cancel the event and so informed the University’s Protection Services staff on site. At that time, a crowd of about one thousand people had peacefully gathered at Marion Hall.

"Freedom of expression is a core value that the University of Ottawa has always promoted," said Allan Rock, President of the University. "We have a long history of hosting contentious and controversial speakers on our campus. Last night was no exception, as people gathered here to listen to and debate Ann Coulter’s opinions.

I encourage our students, faculty and other members of our community to maintain our University as an open forum for diverse opinions. Ours is a safe and democratic environment for the expression of views, and we will keep it that way."

Nevertheless, Coulter is still playing her martyr card, and Faux News, I'm sure, is crowing right along with her.

h/t to tom for pointing this out in the comments. Thanks!

fossil of an aquatic animal

A few years ago, I wrote a post about prediction in the historical sciences. This post came in anticipation of the publication of Tiktaalik roseae, a remarkably well-preserved fossil of an aquatic animal very closely related to the first tetrapods. I offered this figure to illustrate the position of a gap in the fossil record as a predicate for how/where we might look for fossils that would fit within those 'gaps' in phylogeny.

Yesterday, this picture got a lot more complicated. With the publication of tetrapod footprints some 18 million years in advance of this gap by Niedźwiedzki et al., the nice congruence between the node order of the tree and stratigraphy no longer appears so nice.

Here's a picture of the trackways (click for the full view):



[More below the fold]


This news has already broken, and I'm usually the last person to blog about it these days. Naturally, Ed Young has a good take on it. As noted by Jenny Clack in Ed's piece, the individual footprints are more convincing than the trackways in terms of their identity. Here's one from the supplementary information file (which is free to access).

[Picture deleted: I made a mistake, reading too fast and posted an image of Triassic temnospondyl footprints! A better image is this digital surface rendering from the main paper posted below]



But how "bad" is the record now that we know this? Well, bear in mind that lungfishes and tetrapods are considered (at least by the phylogenies in question) to be sister groups. That is, they split from their last common ancestor at exactly the same time. The earliest 'true' lungfishes (i.e. lungfishes with toothplates, and upper jaws fused to the braincase, etc.) are Emsian in age, roughly the same age as these new footprints. Recognizable close relatives of lungfishes, such as Diabolepis, Youngolepis and Powichthys, however, are considerably older. Do, we can set a minimum age for the origin of the tetrapod stem lineage down in very earliest part of the Devonian even if we do not have the fossils.

So, not surprisingly, the record is pretty bad. It's certainly 'gappy'. But we should not be too surprised that tetrapods emerged long before the time when we find their first actual fossils.

"We have a village idiot in this country; it's called Fundamentalist Christianity"

Wise words from Frank Schaeffer.

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The video is well worth a watch, if you like to see a former Christian fundamentalist use some damning rhetoric against the batshit crazy group he used to be part of.