Space/Science — HabitableZone

Space/Science » in reply to Fur, ears and domestication...

Ever heard of Rupert Sheldrake's "morphological fields"?

If mental experiences can somehow communicate with the genetic material, a lot of these mysteries might be explained.

But it goes a great deal deeper than that. We know how DNA consists of coded blueprints to help replicate all the proteins found in an organism (not to mention a lot of other proteins found only in the organism's ancestors). But where is the information on how these proteins are then assembled into cells, tissues, organs and organ systems? Sure we can catalog all the materials in a house, such as framing, nails, pipes, wires, bricks, tiles, glues, paints, plaster, drywall, cement and so on. But that doesn't tell us how they are shaped and assembled in order to finish the completed structure. If all the materials to build a house were available at Home Depot, you'd still need several craftsmen's skills to bring them together, in the right order, to build a house. That information is not stored in the list of supplies you take with you to pick up the construction material.

We are not just undifferentiated piles of proteins, we are put together in a certain sequence, over a long period of time (that's what embryology is all about). Where is the information for how to construct a human in the womb stored? I understand it may be coded somehow in the secondary and tertiary structure of DNA, but nobody really knows for sure. BTW, "secondary and tertiary structure", (and there may be other levels) refers to the contortions and shape the DNA contorts itself into. The primary structure is the double helix itself, we have a pretty good understanding of that. But that double helix twists itself pretzel-like into higher order morphologies...

And consider this, the DNA not only codes up the design of the adult organism (with variations), but it also communicates the structure of that life-form at different stages in its life. Invertebrate DNA also must know the anatomy and physiology of the egg, larvae, pupae and adult stages of the animal, which may be quite different, each magnificently adapted to totally differnt environments and ecological niches. How the hell does something like that evolve just by a purely stochastic process like natural selection? Some species have alternate lifestyles, popping back and forth between to very dissimilar organisms; some coelenterates alternate between a polyp and medusa body plan, and the common fern alternates between two totally different types of
architecture. Sponges, on the other hand, have many different types of cells and tissues, but no organs as we know them. Still, somehow they manage to organize themselves into recognizable shapes. Some creatures, like the Portuguese man-o-war, aren't even organisms per se, they are colonies of specialized individual animals which cannot exist independently. And for some real weirdness, read up on the life cycles of slime molds.

In social insects, the anatomy and physiology of each caste (worker, nurse, warrior, queen, drone) must be coded separately in the DNA, plus the instructions to trigger the desired form by simply altering the diet of the larvae. How did that evolve from a pruning selective process like our snow-dwelling furry critter?

I think there is a hell of lot going on that we don't understand, and I don't think some puerile hypotheses like Creationism or "intelligent design" can ever hope to explain any of it any more than "natural selection" can. There is something going on, some kind of information processing at the cellular and molecular level that is truly wonderful.

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