“The evolution of biological materials is a critical, yet poorly understood, component in the generation of biodiversity.” From: Spider dragline silk: correlated and mosaic evolution in high-performance biological materials. Dec 2006. Swanson BO, Blackledge TA, Summers AP, Hatashi CY.
CLADISTICS is an interesting topic in evolutionary biology. It’s about the evolution of shapes or characteristics. Dr Andrew Parker’s book: “In the Blink of an Eye” (ISBN 0-7432-3988-1) is about his theory on the evolution of the eye and vision in the Natural Kingdom. An important region on the planet of note in this discussion is the Burgess Shale in Canada. It is here in the shale deposits that the fossil remains of the earliest soft bodied organisms is found and it is interesting that they have hooks, i.e. that they have tarsii and mandibles and sometimes other hook-shaped appendages. These organisms look like woodlice or shrimp, after a fashion and the fossils are up to a foot long. But they don’t have eyes yet – so it provides Dr Parker with a starting point. A datum.
Cladistics is about the evolution of shape as I said before. Mathematically speaking one could classifiy shapes by the number of sides they have, their shape and their angles, perhaps. One could classify a spherical shape as being of class 0, a rod shape as being in class 1, a hook shape to be of class 2 (a bent rod), a y-shape as being of class 3 (one intersection) etc. And ponder over how they arrived at being. What is the control system in place that converts DNA and its combinations with shape and growth? We know in some cases erosion contributes – i.e. the blunting of animal claws from walking but the logarythmic spiral of the tiger claw arises from uneven growth speeds across the root of the claw. What controls that?
Whoops! I should have contextualised para 1 a bit better. The theory goes that the fossils of the Burgess Shale come from the Cambrian Era, the era of a huge explosion in the number and variety of organisms on this planet, coming out of the “promordial ooze”. There was light (So it was the first day of creation I think) and so there was reaction to light i.e the signs of the first primitive structures that were sensitive to light too – Cladistics. There were claws/hooks/tarsii around at the time too, it seems. And probably silk? Evolution would seem to indicate so since hooks came first, before a form of eye/vision. Maybe that is what it (the theory of evolution) is saying, maybe not.
I have mentioned the tiger claw, but tigers were hiding back then it would seem cos there is no evidence of them in the fossil record of the Cambrian Age. But not all hooks of course originate through uneven growth patterns. A burdock hook is a rod that curls with marurity of the flower. A insect tarsii evolves in the egg in shape and then grows through the chitin moulting. On the other end of the scale, an elephant’s tusk simply curls in uneven growth, but not with any regularity between individuals (I hope I’m not rash in saying that).
All of these have different control mechanisms and consist of different Biomaterials.
It’s interesting, no?
There’s a reason why I am thinking along this path, Igor.
I vant to build mein own structure!!
Yes – how would one manufacture/grow a Class 2 structure? A hooked rod. Through curling it or uneven growth or molding it or erosion? Or layered manufacture? What if one had the templates and was into membrane technology? What could one do? Self-assembly or laser sintering? A bioreactor or a machine-shop?
In limbo-dancing the chant goes: “How low can you go?”
But for me it is: “How small can you go?” because we are talking small here, very small, micro-sized.
So if we consider the Burgess Shale then it is cellulose and chitin that appear to come first (there are fossils of soft plants too). So is it shape, function, or material, or DNA? What comes first and which has the simplest control system to copy (mimic) or emulate? Does one lay material down or extrude it up? How to do it in a controlled fashion with low risk?