We... already have a treatment for HIV after you get it. The cocktails are now such that HIV has very little effect on life expectancy.

I would PM you if I could. don't even know if slashdot has that functionality. email me, krisrhodes at gmail.

The practical boundary is certainly microfossil measured, but those aren't as good a world-wide unique time stamp as the iridium anomaly - which in theory is uniform through the world and specific in time to a one year or so period. So yeah, no real disagreement here, but I'm also not about to start reading papers looking for the consensus K-T boundary either.

They only have one picture of the "fossil" in the paper, and to be honest - it doesn't look like one to me. Preservation looks absolutely terrible. They don't really talk about preservation. It doesn't look like there is more of the animal there (which does, of course, highly support transport). If you can't access the paper, let me know and I'll send it.

It is my understanding that the "official" K-Pg was defined based on the iridium spike, even though that was not what was used in this study.

But there isn't a -gap-. There is uncertainty as to the exact timing. A gap is a period when you are sure there isn't anything; uncertainty means you don't know. To the best of our knowledge - and constantly improving as more work is done - the uncertainty periods are getting smaller. This is evidence for concurrence. Concurrence is not disproven, and the evidence that supports it keeps getting better as it is refined.

There are no terrestrial beds of fossil bearing rock that also contain unequivocal markers of the K-T iridium spike. That's why we have correlation. There are lots of continuous beds of fossil bearing rock that do contain the K-T and show evidence of mass extinction - in the marine realm. Foram extinction and population is well documented and not disputed, as well as other marine creatures. The most likely explanation is that the impact had some role in the extinction.


|...as the one true theory....

The article doesn't claim anything about one true theory, and neither did I. Straw man at it's best. Scientists look for evidence and weigh it. I recommend you learn more about Bayes theorem and then reexamine the evidence.

Gradual extinction is still a possibility, but that's been covered by other studies and there is little to no evidence that specifically supports it.

What this paper does way in on is the claims that the extinction happened a long time (3m of rock worth of time) before the impact. If this is an unreworked bone, those claims are dead.

>Sedimentation rates are estimated to have ranged from 52 to 81 meters per million years. Thus 13 cm represents no more than 2500 years.

Sedimentation rates are not constant. They tend to come in fits and bursts. I would not draw that conclusion from the evidence.

The thing is - if they were in fact concurrent - then we'd expect that as better data becomes available, the dates converge.

This is exactly what has happened over time. There's actually new work being done by Zircon workers that continues to close the gap.

And yes, this IS evidence that supports that dinosaurs went extinct at the boundary. It increases the possibility of that, to the exclusion of others possibilities, by at least a little bit.

Hell Creek formation = fluvial (river) deposits.

Reworking is always a possibility.

This specific fossil is claimed to have been found in an overbank deposit, which means that it was out on the flood plain, which if true means it is unlikely to have been reworked. But I'd want to see it for myself.

This is one of the bigger problems with the impact hypothesis. Also, amphibians were largely unaffected, and they tend to be very sensitive to environmental problems. Impact having an important contribution to the extinction is still the leading hypothesis, even if there are some things that aren't understood.

In geologist terms, 13cm is "right up until". Add in the Signor-Lipps effect and it's statistically indistinguishable.

http://en.wikipedia.org/wiki/Signor%E2%80%93Lipps_effect

That's not how it works.

Considering the vast amount of time captured in even 13 cm of strata, there are many more generations of dinosaur corpses created and sorted through the taphonomic filter than would be created by a sudden extinction event. The deposition associated with the Hell Creek is one of rivers - which means there's a lot of energy to destroy things, as well as problems transporting from death location into the river to begin with. Simply put, there is no reason to expect that you'd fine a single bone from the last generation of dinosaurs - and even if you did, you'd have a hell of a time proving it.

Here's an example paper from the modern that looks at this problem : http://www.cornellcollege.edu/geology/greenstein/personal/Reprints/Diadema.pdf

Clear record of mass mortality, like you expect, requires exceptional preservation such as that captured in the Burgess Shale. That isn't the case for the Diadema, or for the Hell Creek formation.

And yes, of course you can associate things at 13cm. The number of vast changes in flora and fauna at the K/T boundary match up as well as could be expected with the Iridium spike and other impact markers. This is strong evidence that there is an association.

This one.

Good coding skills are useful in almost any industry, and across all the sciences. Choose where you want to work, take courses in the appropriate field, and your programming experience you already have will carry you far.

Also, the whole point of a Bachelor's is that it provides a broad education. If you don't want a broad education, you don't want a BS.

Wut?

Tons of people are denying climate change. Google "No warming since 1998" for countless examples.