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Daniel Boyd

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Does the genome contain enough information?

The genome contains precisely the information needed to produce the collection of proteins contained in the cells of an organism - no more. It therefore has no information left to determine the entire three dimensional structure of the organism, its organs and cells. Please explain why this is not true.


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    Sep 20 2013: From Wikipedia: "An analogy to the human genome stored on DNA is that of instructions stored in a book:
    The book (genome) would contain 23 chapters (chromosomes);
    Each chapter contains 48 to 250 million letters (A,C,G,T) without spaces;
    Hence, the book contains over 3.2 billion letters total;
    The book fits into a cell nucleus the size of a pinpoint;
    At least one copy of the book (all 23 chapters) is contained in most cells of our body. The only exception in humans is found in mature red blood cells which become enucleated during development and therefore lack a genome."
    You are asking for an explanation as to why it is not true that the genome is insufficient to control the "entire three dimensional structure of the organism, its organs and cells."? You are (rightly) admitting it is not a justifiable true belief so why not just go with that?
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      Sep 21 2013: I'm posing the question to challenge the contemporary (and understandable) assumption that genetics and heritability are synonymous because the genome is the only information that is physically transferred from one generation to the next.

      I thought it would be interesting to start a debate on the discrepancy between the amount of information in the genome and that required to define the three dimensional form of a multicellular organism.

      My question (to people who ascribe to the assumption) is therefore how they explain this gap. I'd also be interested to hear from people who hold other opinions on the formation of biological structure.
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        Sep 21 2013: So what essential biological information do you imagine is passed from generation to generation by other than genetic means, and what are those means?
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          Sep 21 2013: The information I am referring to is the entire complex structure of the organism that is replicated in each generation. It is the information that makes the difference between a random pile of proteins and other biological molecules and an operational cell/organism.

          My point is that I can't see that there is any space for this in the genome. I'm trying to find someone to defend that idea!
      • Sep 23 2013: Genome is NOT the only thing that is passed down through generations; to be on the technical side, what contains in the egg that get passed down from a mother to her child include proteins and RNAs and other stuff. The mother also provides an environment that can determine how the fetus is to develop. There is also genetic imprinting called epigenetic (a system that can turn off certain genes; it is not wholesomely understood yet) that can be passed down from either parent to the child. Genetics and heredity are NOT synonymous and that has been generally accepted in the scientific community.

        As to what make us what we are, this is more complex than simply our genome. The simplest example is the observation of identical twins growing up to be two separate beings with separate consciousness and thinking.

        I would say that the genome encodes everything that we are; we cannot make what is not encoded by our genome. Most of our genes are turned off and it is what is turned on that makes us what we are. But what influences these decisions are not completely understood.
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          Sep 23 2013: Thanks for your contribution, Tina, and certainly epigenetic factors are at work here. It is clearly of significance that the genome is not an isolated entity but exists within the controlled environment of a fertilised egg with various other cellular components.

          However, when it comes to quantities of coded instructions, the genome would seem to contain massively more specific information than this environment - and still doesn't seen to have nearly enough.

          Surely an epigenetic influence that turns off genes only reduces the information available, rather than increasing it?

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