12 February 2024

What's wrong with a DNA-centric view? Philip Ball (2024) How Life works

Philip Ball: How Life Works

In his new book How life works science writer Philip Ball makes fun of the gene-centric and DNA-centric view of biology. The figure below illustrates this view. First, there is DNA, then complex stuff happens, and then ... there is life. What's wrong with that view?

The popular view of how genes create living things
according to Philip Ball

According to Ball understanding genes will not enable us to understand life. Genes are not alive, cells and organisms are alive. Genes were never alive. If there is anything like a language of life, it will not be found in the genome. The genome as a "blueprint" for the creation of an organism is a favourite but misleading metaphor. There is no 'book of life'. DNA is no 'instruction book'. In biology every explanation starts with DNA. But according to Ball, it is trying to understand literature with a dictionary. (In my opinion, you can't learn a language without learning the words first! And that is what biologists are doing!). The complete sequence of the human genome did not produce insight in what life is. It is more complicated than that. DNA doesn't solve all the problems of biology. DNA doesn't tell us how cells work. The cell is not a machine. The cell is not a computer. No computer today works as cells do. The problem is we put genes at the start and bodies at the end. Genes are not a sufficient explanation of the organism. DNA is not the Master. DNA is the servant. That is Ball's new view of biology. In short.

My reaction is: There are good reasons to start with DNA. Crick's so-called Central Dogma of molecular biology (the illustration is in Balls' book) starts with DNA for a good reason. The information flows from DNA to RNA to proteins. The defining property of the central dogma is: directionality. The information flows from DNA to proteins, not from proteins to DNA. Crick's central dogma starts with DNA because that is how information flows. There isn't a process in the cell that creates DNA. DNA isn't the endpoint. So, necessarily DNA must be the starting point.

Secondly, Darwin had a very speculative and wrong theory about heredity. We now know that DNA is the carrier of heredity. Not proteins. DNA is by far the most important substance that is transmitted from parents to children. It explains why children are similar to their parents. Delete DNA from the egg cell and forget about the baby. The complete DNA sequence of a species defines the species. It is the difference between us and chimpanzees. Humans produce humans, chimps produce chimps because of different genomes. All this is not denied by Ball, but he isn't impressed by this kind of biological knowledge.

I think, we should not underestimate the enormous progress in scientific understanding of life, heredity and evolution. If we have a look at the history of biology since Aristotle, we can certainly claim that we finally know what Mendelian genes are, finally we know what chromosomes are made of, finally we can link genes and chromosomes and explain Mendelian laws in molecular and chromosomal terms, finally we know that species are characterized by the number of chromosomes, equally that males and females differ in their chromosomes, finally we understand sex in chromosomal terms, finally we know that genes, not proteins, are the material basis of heredity, finally we know the chemical structure of DNA (Watson & Crick), finally we know precisely how genes code for proteins (the genetic code), finally we know the complete sequence of the genetic material in an individual (the genome), finally we know in biochemical detail what mutations are, finally we know that mutations are necessary for natural selection and evolution. We can now explain many genetic diseases. We can even correct some of them. These are powerful scientific explanations previous generations of scientists only dreamed of. This is a tremendous scientific progress fully comparable to what Newton and Einstein did for the physical sciences. Ball seems to forget all this.

In chapter 2 Ball points out that despite all our new knowledge of genes and genomes, biologists still don't understand life. But hold on, which of the natural sciences could claim complete understanding of the field they study? Furthermore, is it really true that progress in molecular biology is slowing down? Or has come to a standstill? Is there really a crisis?

12 Feb 1809
What about evolution?

"I must stress there is nothing in this new view that conflicts with the neo-Darwinian idea that evolution shapes us and all other organisms and that it depends on the genetic transmission of information between parent and offspring. However, in this new view genes are not selfish and authoritarian dictators. They don't possess any real agency at all, for they can accomplish nothing alone." (Prologue) .

No real agency? Accomplish nothing alone? Viruses like SARS-CoV-2 know that very well. They absolutely need the help of the human host. They can accomplish nothing alone.  Without the help of humans SARS-CoV-2 could not have caused a pandemic.


Note. In a next blog I will continue writing about How Life Works

See Wikipedia about Philip Ball: Ball holds a degree in chemistry from Oxford and a doctorate in physics from Bristol University.

5 comments:

  1. Hi Gert, goed om te zien dat je het boek van Philip Ball "How life works" gelezen hebt. Ik kom er later op terug.

    ReplyDelete
  2. https://whyevolutionistrue.com/2024/02/12/yet-another-misguided-attempt-to-revise-evolution/

    Jerry Coyne “bespreekt” dit boek op basis van de recensie van Denis Noble. Maar hij weet al genoeg.

    ReplyDelete
  3. Hi Rolie, nice to see you are alive and kicking! Let op: ik heb nog niet het complete boek gelezen. Dit blog was vanwege 12 februari!!! Er komt tenminste nog eentje over dit boek.

    ReplyDelete
  4. Hi Frank, dank voor de link. Ik zou zeggen: verspil je tijd niet aan 'een review van een review', (onwetenschappelijk!) maar lees het boek eerst! Vooral als je het erg druk hebt!

    ReplyDelete
  5. Gert, ik ben benieuwd naar je volgende post met hopelijk meer commentaar op de grote lijnen van zijn boek.

    En, alvast iets over de grote lijn van het boek, zoals ik die eruit gehaald heb.
    Als ik Ball goed begrijp argumenteert hij voor een visie op het leven waarbij rondgaande causaliteit de hoofdrol speelt (ook al heeft hij dit begrip zelf niet zo expliciet genoemd). Telkens gaat het om top-down en bottom-up causaliteit tussen de verschillende lagen van organisatie in een organisme.
    Genen zijn een onderdeel van een veelheid aan complexe processen die niet gekenmerkt worden door lineaire causaliteit (van beneden naar boven) maar door feedback-lussen tussen de verschillende niveaus van het leven: genen, netwerken, cellen, weefsel, lichamen en groepen van organismen in ecologische systemen. Al deze lagen zijn complexe systemen die vooral gekenmerkt worden door (mijn woorden) de wetmatigheden van biofysische fenomenen waarvan het gedrag te begrijpen is m.b.v. de chaostheorie. Ook al noemt Ball die theorie niet (nou ja 1x de catastrofetheorie), hij gebruikt wel vaak terminologie uit de chaostheorie, vooral: attractors. Attractors omschrijft hij als kuilen of bassins in een landschap van mogelijkheden. Ze heten attractors omdat de eindtoestand van een systeem als het ware naar een van die kuilen (een van de mogelijke eindtoestanden) getrokken wordt.
    Eerlijk gezegd: ik zou dit allround schema misschien niet herkend hebben wanneer ik niet zelf in mijn boek (De kosmos en het leven, een Meesterwerk) daar over had geschreven.
    Denkend vanuit complexe processen met rondgaande (circulaire) causaliteit wordt de vraag wat het belangrijkste deel van het systeem is in feite onbelangrijk. Als we dan toch een organiserend midden willen zoeken, zou ik over cell-centered spreken.

    Ik ben naar je volgende blog over dit boeiende boek van Philip Ball.

    ReplyDelete

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