Genome complexity in embryology: non-DNA information (Introduction)

by David Turell , Sunday, June 03, 2018, 20:41 (2153 days ago) @ David Turell

Carried by positional information, membrane information and electric field information:

https://evolutionnews.org/2018/06/life-exponential-life-exhibits-intelligent-design-at-...

" After the nucleus duplicates, the fertilized egg divides into two daughter cells. If the plane of division corresponds to A, each daughter cell inherits not only a nucleus but also portions of all four regions of cortical information. .. But if the plane of division corresponds to B or C, the daughter cells do not inherit a full set of cortical information, and their development is blocked even if they each contain all the necessary DNA.

"Regional differences in cells and embryos can be specified in other ways besides localization of RNAs in the cortex. Two of those ways have been studied in great detail: the “sugar code” and the “bioelectric code.”

"Most proteins in living cells — including those in membranes — are chemically bonded to carbohydrates called “glycans”. The nucleotides in DNA are linked together end-to-end in a linear molecule, so DNA sequence information is one-dimensional. In living cells, the subunits in proteins (with a few exceptions) are also linked in a linear chain. But glycans can be linked together in complex three-dimensional ways, so their information-carrying capacity exceeds that of DNA and proteins by many orders of magnitude.

"The information carried by glycans has been called the “sugar code.” The sugar code is “interpreted” by proteins called lectins, which “recognize” specific three-dimensional structures of glycan molecules. Glycans and lectins play an essential role in communication among cells and help to guide cell movements in a developing embryo. Experiments have shown that membrane patterns of glycans change in the course of embryo development.

"In addition to the sugar code, probably all living cells generate electric fields across their membranes. They do this by pumping charged ions through channels in their membranes, creating a “bioelectric field.” The pattern of membrane channels determines the form of the bioelectric field, and the form of the field changes during embryo development.

"Bioelectric fields are correlated with important developmental events. In frog embryos, for example, large ionic currents start flowing out of the sites where the hind limbs will develop long before the limbs appear.

"Many experiments conducted since the 1980s have confirmed that disrupting bioelectric fields causes disruptions in development. .. The spots where eyes normally form are more highly charged than the surrounding tissue; if the charge is neutralized, the eyes that develop are small or deformed. Sometimes, eyes develop elsewhere on the tadpole’s body, including its tail.

"How do electric fields influence development? In the 1980s, biologists exposed embryonic cells to artificial electric fields of the same strength as ones the cells generate naturally. Some types of cells migrated toward the positive pole, while other types migrated to the negative pole, suggesting that one way bioelectric fields affect embryo development is by directing cell movements.

"In 1995, biologists Riyi Shi and Richards Borgens concluded that bioelectric fields “may provide a three dimensional coordinate system” that helps to specify form in embryos. In 2013, biologists AiSun Tseng and Michael Levin wrote that such fields may provide “templates of shape,” and that a full understanding of embryo development will probably require cracking the “bioelectric code.”

"So localized RNAs in the cortex, glycan patterns on the membrane, and bioelectric fields generated by ion channels in the membrane all carry spatial information. Although individual molecules may be specified by DNA, their three-dimensional patterns are not. Taken together, these patterns constitute a “membrane code” that is independent of DNA sequences.

"In 1983, biologist Robert Poyton suggested that biological membranes carry “spatial memory,” the units of which are spatially localized proteins. Poyton wrote: “Realizing that genetic memory is one-dimensional, along a DNA molecule, whereas spatial memory is likely to be two-dimensional, along membrane surfaces, and three-dimensional within the cellular interior, it is probable that spatial memory is more complicated and diverse than genetic memory.”

"In 2004, biologist Thomas Cavalier-Smith wrote that the idea that DNA contains all the information needed to make an organism “is simply false.” Animal development creates a complex three-dimensional multicellular organism not by starting from the linear information in DNA… but always starting from an already highly complex three-dimensional unicellular organism, the fertilized egg.”

"So the membrane code carries essential biological information that is independent of DNA.

***

"But the existence of the membrane code shows that the Central Dogma is false. And the materialistic idea that evolution is unguided cannot account for the complex specified information in DNA, much less for the extensive complex specified information in the membrane code. Just as the information in DNA points to design, so does the information beyond DNA. "

Comment: Embryology is too complex for chance. It involves using spatial, mechanical molecular shale and electrical field information. After life evolved it had to use embryos when sex appeared. Embryology is as much a miracle as the start of life itself.