Is Information Only Present in the Genome?

I agreed to this a long time ago. The nature of cell division ensures that daughter cells inherit some of the cellular constituents of their parents, but these constituents will eventually disappear. To replace degraded components, we need information (like a blueprint) to synthesize new ones. Only genomes carry such information. Every single protein in our cells is synthesized using information from DNA and proteins are the mainstay of any cell or organisms. Thus, its obvious that what cellular organization should be is kept in DNA, however, to go from DNA to that cellular organization we need other cell parts.

For example, in a typical mammalian cell the cytoplasmic levels of sodium ions is far below extracellular levels. This chemical gradient is integral to the existence and functions of the cell. To maintain this gradient, we need sodium pumps which push sodium ions against their concentration gradient into the extracellular space. Sodium pumps are proteins capable of utilizing ATP as a source of free energy to expel sodium ions from the cell. During cell division, parental sodium pumps are passed down to progeny, but these pumps don’t last forever and eventually degraded. The information needed to make them persists in DNA, so it means that as long as the cell can tap into that information, it will keep on maintaining its organization by always making new pumps to replace degraded ones. It is this sense that DNA hold all the information needed to maintain or establish cellular organization.

Why Mercer and Rum disagree within this beats me.

I believe all the scientists here agree on all the biology, and Paul Davies himself did not say anything otherwise. The contention is with regards to the meaning of information. This thread is titled, “Is Information Only Present in the Genome”, and the answer is no, unless you a priori define information as genetic information.

If the extranuclear environment has any degree of organization, that is information by definition. It is not complete entropy, so it is information. It’s current state must and will relate to future states, however weakly and ephemerally. The way I read Davie’s statement is that the genetic code has always been a unbroken part of a larger biological system, and reaching back into time and physics there has never been a moment of discontinuity in that regard. His point is not to diminish genetics but to emphasize its integrated nature.

This is no support to the idea that, because there is a mechanical aspect to such information, that design is implied. That misconceived notion is what kicked off this discussion.

EDIT: grammar, diction


Good, but I don’t know what you mean by “the link.”

My point is that the blueprint is inherited. You’re conflating the recipes in DNA with the blueprint that is not stored in DNA.

No, that’s not obvious at all. Common descent offers zero reason for that organization to be stored in DNA, because it’s always been present.

Beautifully put.

The thread title asked the wrong question, because everyone here agrees there is information outside genomes.

What I disagreed with in the Imari Walker and Paul Davies paper is in the boldened part of the quote:

This seems wrong. AFAIK proteins, enzymes and RNA molecules maintain or establish cellular organization. Your cells can take in or remove certain ions, sense certain signals, and do a lot of other stuff thanks to the aforementioned biomolecules, especially proteins. Proteins are the workhorse of cells. Since DNA holds information (exact linear sequence of nucleotides in genes and their regulatory sequences) needed to make those proteins (which will then go on to shape cellular organization), its obvious DNA contains the blueprint for constructing cells. These are excerpts from Molecular Biology of the Cell, sixth edition, pages 369 and 7 respectively and they disagree with the Davies paper.

Proteins control that organization and how those proteins should act is a function of their amino acid order and composition, which in turn is a function of the DNA sequence which encodes them. What that organization should be is conserved in DNA.

The blueprint is ultimately stored in DNA.