Devonian Spiny Nautiloid

[Architeuthoceras]

(and I'll read this tomorrow)

Can't help Hajar, first meeting of fabricational noise for me too.

 

[DWhatley]

The site with the water info now seems to be functioning. It was likely down for maintenance or a server failure. With all the issues we have with declining water quality and farm run off effecting our oceans, it would seem that Oman would be well served to avoid these issues by importing most farmed foods and feeds but besides oil what does it have to balance the trade efforts?

 

[Terri]

Can't help Hajar, first meeting of fabricational noise for me too.

Now that is an interesting article! But will have to read a few more times for total comprehension.

 

[cuttlegirl]

Yikes, I used that paper in my first research on cuttlefish, will have to reread. We need Monty , but I will do my best to remember/reread and translate.

 

[Hajar]

Thanks very much Cuttlegirl, that would be great. Most of this language is new to me.

I enjoyed reading the Anderson paper, but didn't find that it helped very much with the spiny nautiloid explanation, though it gives some leads (e.g. "self-organizational behaviour in far-from-equilibrium systems"). Groping towards understanding, the flavour I get is something like: It's not a comfortingly simple arms race story in which the nautiloids become spikier in defence against increasingly vicious predators since the smooth nautiloids around at the same time were about as successful. This group of spiky nautiloids appeared after an extinction event (niches were vacant), as did new smooth-shelled forms. There was no particular external forcing on the development of the spines. The emergence of the pattern was accidental, "serendipitous", a kind of intrinsic evolution.

Another quick browse found this, which talks about how development “is to a considerable degree self-organizing. We do not have genes for individual ridges comprising our fingerprints; nor do we have genes that inform each neuron in our brain where it will synapse and where its dendrites will grow. We do have an inherited program for making certain patterns of neuronal connections, but there is considerable room for variation.” It goes on to discuss fabricational noise and intrinsic evolution (page 184). I read half of this then skimmed to the end - it's getting late here.

On the right track do you think?

 

[Hajar]

This paper has some illustrations of colour patterns on Rutoceratoid (Ptenoceras) nautiloid shells.