The Major Transitions
We review various identifications for the major transitions in the evolution of life, and propose one that includes the evolution of
passive physical and chemical information structures in the universe before the appearance of
active information processing systems of the biological world.
John Maynard Smith (Origins of Life, p17)
- Replicating molecules (Populations in protocells)
- Independent replicators (Chromosomes)
- RNA as gene and enzyme (DNA genes, protein enzymes)
- Bacterial cells - prokaryotes (Cells with nuclei and organelles - eukaryotes)
- Asexual clones (Sexual populations)
- Single cell organisms (Animals, plants , and fungi
- Solitary individuals (Colonies with non-reproductive castes - ants, bees, termites)
- Primate societies (Human societies)
Marcello Barbieri (Code Biology, pp.180-182)
- Origin of macromolecules, bondmakers to stick monomers together at random, producing polypeptides, polynucleotides, and polysaccharides
- Origin of random proteins. No link between nucleic acid and amino acids, so needs code
- Origin of the first cells - Archaea, Bacteria, and Eukarya, three distinct signal codes?
- Origin of eukaryotes, splicing codes, cytoskeleton codes, compartmentalization codes, histone code
- Origin of embryos
- Origin of mind, universal neural code, sensations to neurons, firings of action potentials and firings
- Origin of interpretation, abduction
- Origin of language, only codes can create novelty?
Information (negative entropy) Transitions (new information structures, new processes, new assembly lines)
Elementary particles, atoms, galaxies, stars, and planets with negative entropy flows (the Ergo)
which exhibit complex "dissipative processes" far from equilibrium
|
|
Pre-biotic molecules - amino acids, lipids, short proteins, ATP, polypeptides, polynucleotides, and polysaccharides form in negative entropy streams of matter and energy
|
|
Membranes, protocells, autocatalytic self-assemblies, intracellullar communications - the appearance of information processing, proto-life?
|
|
Ribozymes, inheritance, and communications (RNA assembling variant versions of itself), viruses
|
|
DNA genes, proteins replace RNA as enzymes, central dogma, plus (genotype > ribotype > phenotype)
cytoskeletons, compartments,
codes, channels, contexts, meanings
|
|
Organelles, organisms incorporate unicellulars (and viruses) for their functional behaviors, horizontal gene transfers, epigenesis
|
|
Intercellular communications by physical/chemical contact, colonies, symbiosis
|
|
Multicellular organisms, organs, tissues, instinctual organisms inherit behaviors
|
|
External storage of signaling information by many multicellular organisms, languages?, pheromones, in umwelten
|
|
Neurons appear, sensations fire action potentials, high-speed communications
|
|
Minimal proto-mind, wired-together neurons fire to recreate sensations and experiences, signs?
|
|
Learning, foresight, free will (the Cogito), humans foresee death, invent idea of afterlife
|
|
External storage of abstract human information (ideas, knowledge), shared with entire community (the Sum), first humans to see beginning of universe and imagine ends
|
|
Normal | Teacher | Scholar