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Just posted this to Pharyngula at the “An ontogeny of toilet drain behavior” thread


Very nice from Dr Fleury to finally inform us of what L2/R2 could be. Never late to do well. The funny thing is that he commented here but haven’t send me a message about it! That’s weird. I’m asking for evidence concerning L2R2 since august 2007.

Let’s see what we have here anyway.

The first pair of vortices Fleury claims as R1L1 are shown by CuiC et al [Dev Biol. 2005 Aug 1;284(1):37-47. doi:10.1016/j.ydbio.2005.04.021, during stages ~1-3+.

For more than 2 years the presence of the R2L2 vortices was assumed to be visible during the same developmental period and modeled as the result of a single phenomenon.

The second pair of vortices Fleury claims as R2L2, presumably shown here, are situated between stages ~8-9+. They traveled in time!

Assuming that we have evidence for R2L2, the model presented by Fleury describing simultaneously the two pairs, R1L1 and R2L2, must be wrong and he should recall his paper (doi: 10.1051/epjap/2009033) and clarify this point (along with correcting everything else) before submitting it again.

Unfortunately, it seem’s that the cell trajectories are manually spotted, the green color must not mislead anybody to confuse it as GFP expression, which is the case with Weijer’s lab experiments. Manual spotting is not the best technique to follow a particular cell population during a process where everything is moving in 3D. Not even ink or membrane dyes were used!

The first gif file even as annotated by Fleury don’t show any vortex.

The second gif file is even worse, it is obvious that the 2D depiction of the vortices is just false, sorry Dr Fleury, the cells/tissues movement is in 3D, you can’t just get a projection in 2D and try to make it look as you would like it to be. This seems to be a recurrent problem. The animation starts when the 8th pair of somites is forming at stage 9+, always faraway in time.

Let me summarize Dr Fleury:

IF those are the R2L2, the vortices contributing to the formation of the hindlimbs THEN

the previous positioning at stages 1 through 3+ was false, as I have argued the last 2+ years

AND

the published models are false [cteappv (2009) & epmag (2005)]

AND that have nothing to do anymore with a 2D flow you claim to be at the origin of the tetrapods.

Now, we don’t really think we have evidence from a 2D manual projection of a 3D moving structure, in the absence of a tissular marker.

And I wonder what you will prefer, drop your model which assumes a (almost) 2D cellular layer and a hyperbolic flow forming simultaneously the four vortices, or try to get more consistent evidence (if any available).

Oops 090630

vincent fleury:

By the way “I can has L2/R2″ is not a sentence

Aha! this is not a sentence. I was waiting for this one since I read the paper.

For Dr Fleury first step here, and second one here, both necessary to get the flavor.

For everybody else, a puzzle served below [p22 col2 §1]:

The significance of the reversed flexion of the hindlimb in 10% of the experiments reported in reference [59] is unclear since the electroporation experiment used to insert Tbx5 in the hindplate prior to hindlimb growth has a polarity in itself. If this experiment would be confirmed, it would be an uncommon case of a chirality, directly induced by a scalar non-chiral field. This would suggest that Tbx5 codes for a chiral molecule.

Maybe Dr Fleury will take the time to provide the solution. Hopefully this will not end as “I can has chirality??“.

While he is visiting lolcats and fails to have an insight about lolchickens I’ll give it a try to prepare a question for him.

help a fellow hang himself

A funny side-effect of PZ Myers “An ontogeny of toilet drain behavior” was to bring Fleury’s theory within the range of one of the famous crackpot detectors, Suzan Mazur.

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Now, that’s a clarification!

At least!

Vekris : the antero-posterior construction of animals is bullshit, the induction of limbs by genes is bullshit, the colinearity of hox genes is bullshit, the selection of tetrapods by evolution is bullshit, the duplication of genes between hindlimbs and forelimbs is bullshit

and you now know it, better than anyone else.

Well, no, I don’t know it and cteappv certainly don’t explain it and it’s not by not providing evidence that anybody could support such claims. And “anybody” includes physicists.

But that little burst is quite informative, isn’t it? Clarifying the authors position in the scientific landscape.
Now, a lot more people know what Vincent Fleury believes.

There is only one point of interest for me, as it is my main disagreement with Fleury:

the selection of tetrapods by evolution is bullshit

Quite clear, received 5/5, thank you Dr Fleury.

Now, he certainly misread my comment, but that’s not news. Let’s continue with the science of cteappv; maybe with a small stop before that 😉

3.3 The limb field

This is the last part of “The genetics of vertebrate development”. Not much about most of the features of vertebrates were presented and this last part is about just “the limb field”. There is a lot of interesting papers out there one could read to learn about the subject.
It would be really sad if all you got is what Fleury present in cteappv.

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Stop the rotatives!

0E9A6A33-8137-4BBB-A818-F1E2F1E119C1.jpgYou foolish biologists, stop whatever you’re doing right now and learn from the wisdom of our physicist :

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RTFM

RTFM Avoid embarrassment.

What may happen when one is decided to have great theories about a subject he is not familiar with? Except all those irritating rhetorical turns that he produce1 sometimes there are great comical effects.

I just managed not throwing my mouthful of coffee on my laptop (but I do have to clean the floor):

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