Multicellular Organisms
Division of labour
People can gather in a stadium. They meet peacefully towards a common goal (enjoying some sport event). Harari mentioned that with monkeys it would be pandemonium. |
The evolution we are all experiencing now, following the Universe evolution and the DNA-life based evolution.
People can gather in a stadium. They meet peacefully towards a common goal (enjoying some sport event). Harari mentioned that with monkeys it would be pandemonium. |
On 14th May 1610, at 4pm, Ravaillac assassinated Henri IV, the king of France, rue de la Ferronerie in Paris. The historian Michel Cassan studied the urban archives in 240 towns in France. He found that the towns that were along the postal network setup by Sully received this important piece of information on the same day. By 21st May, all towns in France had been hit by the news (7 days later). On Wednesday 8th September, news of the king's death arrived in Mexico, via Spain, more than 3 months later.
Ravaillac killing King Henry IV. Painting by Gustave Charles Housez |
In the 21st century, most information takes less than 150 milliseconds to circulate around the Earth.
This is what Buskes calls a fundamental difference/advantage of the Third Evolution over the Second Evolution:
"Apart from the different trajectories, there might also be significant differences in speed by which cultural information is transmitted. In small prehistoric populations of hunter–gatherers the mode of transmission was probably mainly vertical and one to-few, resulting in a relatively slow stream of information and a corresponding sluggish pace of evolution. In our modern world, however, the situation has dramatically changed. With the advent of writing, printing, the internet and the social media, the mode has changed from predominantly vertical and one-to-few to horizontal and one-to-many, resulting in an ever-increasing flow of information
racing around the globe with lightning speed."
This difference is not better intrinsically, but it means the Third Evolution takes over, as speed has become a key adaptation feature.
Ref:
Michel Cassan, La grande peur de 1610. Les Français et l’assassinat d’Henri IV, 2010
Patrick Boucheron, L’histoire Mondiale de la France, sous la direction de, Seuil 2017, Stéphane Van Damme, p. 292
Darwinizing Culture: Pitfalls and Promises, by Chris Buskes, about Peter J. Richerson and Morten H. Christiansen (eds): Cultural Evolution: Society, Technology, Language, and Religion. The MIT
Press, Cambridge, MA, 2013, 485 pp, ISBN: 978-0-262-01975-0
The way science has progressed has been the subject of many theories. Thomas Kuhn has popularized the concept of paradigm. In a scientific field, a paradigm is a set of concepts that more or less fit the mass of experimental data with some models and theories. The whole set tends to preserve itself from accidents which happen in new experimental facts and new theories that can happen now and then. It takes what Thomas Kuhn calls a scientific revolution (overwhelming evidence in theory and/or experiments) to shift from one paradigm to another.
Karl Popper has also questioned what can be called scientific. His concept of refutability is now part of the criteria to select which academic sector can be called scientific (think creationism, psychoanalysis, homeopathy).
On the other hand, Martin Harwit has shown how scientific discoveries have often been obtained simultaneously and by independent people. For example, we can cite Darwin and Wallace, or Einstein and Poincaré, as clear examples that they were onto big discoveries independently. Nobel Prizes often have several independent discoverers of the same new scientific fact. For example, the Higgs mechanism has been found at least twice separately. The periodic table of elements was theorized many times, until it stabilized with Mendeleev: his model was superior to the others because it was predictive of new elements that were eventually discovered.
Here, we think that ideas emerge in some environment. They are basically generated at random, in the brain of various people. Then they are tested within the world environment with experiments: General Relativity had to explain the whole corpus of the gravitation science set by Newton, and it could explain even more (the precession of Mercury perihelion). Then it made the prediction that matter can bend light, and Eddington measured that during a famous solar eclipse.
Science advances by testing hypotheses with a specific method: ideas can lead to predictions in some experimental setup. These tests can be done everywhere and at any time. They can be repeated by anybody. Science is the corpus of ideas which have been tested against experiments with a strict methodology, with repeatability, falsifiability, refutability, and predictivity. Karl Popper has insisted that scientific ideas cannot be proven. Instead, they must contain a way to show how they could be refuted. Experiments must exist that probe the ideas. Otherwise, the ideas are deemed outside the scope of science. This is why science has split from other old disciplines like theology and philosophy.
In any case, we see how Darwinian evolution is at work in the scientific process. The experiment method sifts through all ideas. Ideas which pass the tests get selected and retained.
They are then transmitted to the younger generation of scientists and are assimilated by the public, in the long run. The advance of science has been much faster once the corpus of science could be written and transmitted easily.
This figure shows how new objects were rediscovered in the field of Astronomy (Martin Harwit) |
Here we show how the Third Evolution shares many characteristics with the Second Evolution: the blindness, the randomness, the digital base, the unicity, the diversity, the role of the environment, the inheritance. Today we finish the grand tour with diversity, environment and inheritance.
Evolution happens as a gradual matching between the diversity which is present in the system and the environment.
The star formation rate in a galaxy (First Evolution) is likely linked with its immediate surroundings (made of other galaxies). Spiral galaxies are all over the Universe, but they are all different from each other. We do not stop marvelling at the various shapes of galaxies. There are no two identical galaxies. We know that interaction with the other galaxies is shaping the galaxies. The environment to that galaxy is specific to that galaxy.
Bacteria can be of exactly the same species, but yet they all show slightly different shapes and contents. Ultimately, the origin of species is the response by the (Second) Evolution to various environments. Bats are adapted to nocturnal vision. Fish are adapted to the sea, and so forth.
The brains can look the same, but we now know that the exact wiring has been produced as an interaction between the genetic code and the environment that people get all along their life. Hence, there are not two identical brains, even with twins with the same genetic code. The diversity of human cultures is staggering. But we see how the environment has been the main driving force. Olives are a central culinary piece in Greece, not in Greenland.
Evolution is about gradual changes. Spontaneous and instantaneous transitions do not happen. Each species comes from an ancestor, and this is true for the three evolutions. The tree of life seems to be a generic concept: galaxies are born from the agglomeration of smaller units. The genetic material of children comes from the parents. Ideas, concepts, memes, institutions can usually be traced historically to previous ideas.
Here we show how the Third Evolution shares many characteristics with the Second Evolution: the blindness, the randomness, the digital base, the unicity, the diversity, the role of the environment, the inheritance. Today we deal with unicity.
The Universe (First Evolution) is unique. Wherever we observe the Universe, it looks statistically homogeneous. The laws of physics seem to apply everywhere: the transition levels of hydrogen are always the same, except for light propagation effects (whether gravitational like lensing or redshift, or electromagnetic). The physical constants apply to the whole Universe. For the time being, the best explanation we have got for this lies at the very beginning of the Universe, where a period of inflation has allowed all parts of the known Universe to be connected.
Life (Second Evolution) is unique. Every cell of living organisms uses the same replication DNA-based system. It might not have been the case at the beginning: probably an RNA-based system or even a simpler system may have existed. But this has disappeared, and only one form of life exists on Earth today.
The Third Evolution is carried by the human species. It is now established that Homo Sapiens (HS) is a unique species. Neanderthal species has disappeared... The human brain has emerged from the Second Evolution, but something different is now happening: problem-solving is not left to the slow-process that is life-based tinkering evolution. Artefacts and writings are now massively increasing, outside living organisms. They are only produced by one species: Homo Sapiens. Scientists have shown that HS is rather special, not on the brain mass, but on the ratio of brain mass to total mass.
On that measurement rod, mice fare as well as humans! An even better predictor of "intelligence" is now thought to be the forebrain neuron count.
Richard Dawkins made a compelling case about the main characteristics of the Second Evolution. Here we show how the Third Evolution shares many characteristics with the Second Evolution: the blindness, the randomness, the digital base, the unicity, the diversity, the role of the environment, the inheritance. Today we deal with the first 3 characteristics.
There is no purpose in the evolution of life nor in the new evolution. This was shocking news for the religions in the 19th century, as they posited the existence of an omniscient superbeing controlling everything on Earth. But Darwin's Origin of Species made a big blow in the purpose-led explanations on everything on Earth. A bat is as useful as it is useless. It has no purpose. We think that the new Evolution too has no purpose. No human being, nor any superbeing, is controlling the Evolution carried by the human brain.
This notion is counterintuitive, as we like to think ourselves "in control". But directions and adaptations that we see in the living bodies, or from human brains, "look like" to be with a purpose.
Most of the cultural evolution has happened without any intent. This is what we are going to show in future posts.
The randomness is at the heart of each of the three evolutions:
In the Universe, the fluctuations of the matter-energy density are produced during the inflation as Gaussian from quantum inherent noise. They will then grow linearly during the expansion of the Universe and eventually collapse when the Universe becomes transparent, and produce the large-scale Universe as we observe it today. So the initial conditions are random and, consequently, there are no twin galaxies in the Universe.
Biological evolution too has no built-in intent. It is the constant, relentless workout of the trial and error of genetics that has made life as we observe it today. The primary source of fluctuations in genetics (the rare failures of perfect reproduction from one genome to the next one) is either cosmic rays or viruses. Cosmic rays in a way connect the randomness on Earth to space. Viruses are a special entity that biologists have trouble to classify. But they are clearly parasites with RNA, so they are part of the living “stuff”. The source of randomness here are several folds here: the environment in which the living organisms can evolve (basically on Earth) has a large degree of fluctuations - it is far from thermodynamic equilibrium. Other species influence a given species, they can make it thrive or die.
This is one of the main hypotheses of this essay: the source of new ideas is just some randomness in our brains. Surely what comes out has been filtered by our sense of reason and emotions, but at the source of ideas, what else could be on the table, but some random stroke of genius in isolated brains?
Mendeleev periodic table contains a list of about a hundred different kinds of atoms that can exist in the Universe. Not more. Each atom has a given discrete number of electrons. Hydrogen one. Helium two. Lithium three. And so on.
The genetic information is coded in the DNA which is stored in the nucleus of almost all living cells. DNA is a long code made with only 4 letters.
Which is the basis of the Third Evolution. Clearly, the 6000 languages over the Earth are part of the coding of what is transmitted between human beings. Languages are all made of a finite number of letters or ideograms. The infinity of combinations that can ensue is wired into the simplicity of the building blocks.
The fundamental reason why evolution can only work
through discrete coding systems is that it's the way to avoid the inexorable averaging process (with the Gaussian limit theorem lurking in the background).
There is no doubt that a new evolution has appeared, following the first one (the Universe giving way to complex physics and chemistry in some parts of each galaxy) and the second one (DNA-based life on Earth). This Third Evolution is linked to Mankind, but clearly, human beings are part of the DNA-based life too, and the Universe for that matter.
So what is it? We'll try to make sense into what is happening now in front of us.
Some scientists have talked about cultural evolution, as the new evolution. Cavalli-Sforza and Feldman (Cultural transmission and Evolution: a Quantitative Approach,1981) insist on the need to find the ways culture gets transmitted: parents to children, friends to friends, institutions to individuals. But this notion is rather narrow and depends on different populations on Earth. The cultural evolution lacks universality.
There has been the meme paradigm (The Meme Machine, Susan Blackmore 1999). But this theory failed to provide a universal model of a meme.
We think that it is time to go beyond these theories and see that the Third Evolution is using Mankind but is not centred on it. In the same way as the Second Evolution is using genes but is not centred on genes.
We'll develop that idea in the coming posts.
Life on Earth has been shaped by Darwinian principles. As we know it today, life is controlled by the DNA. DNA pervades all cells of living bodies, whether animals or plants. Life started about 3.5 billion years ago with simple cells and probably some kind of RNA or even less-sophisticated information retention abilities. The evolution of life is staggering. One big step is the start of collaboration between several cells to form a superior entity. Multicellular organisms appeared quite late, probably only two billion years ago.
Darwin and its Origin of Species, then the discovery of DNA as the repository of life information, have put the theory of evolution on very solid grounds. Life on Earth is evolving means that gradual changes have appeared that make all living species be adapted to their environment. Two ingredients are necessary: the randomness of the infrequent DNA mutations, and the natural selection process that invariably filters out the unadapted ones.
The human species has nothing special in that respect and is completely relevant to life of Earth. It is just the end of a non-peculiar twig in the evolution bushy tree.
It is just one species. One species alive today. However, the speed of evolution is limited by the generational renewing. At least a hundred generations are needed to see a new trend appearing. For example, the lactose-tolerant adults in Europe appeared only after several thousand years of selective pressure.
We posit that this second evolution is being swamped by a new one, simply because the third evolution is going much faster. More on that later.
The Universe as we see it today was very different in the past. Evolution is a gradual change over time, and the Universe has evolved. It is still changing now.
Compare this image of colliding galaxies (the Stephan Quintet as recently observed by the JWST) in a nearby region of the Universe:
New elements have since been synthetized in stars and at the end of their lives. These elements were then dispersed in galaxies. This is the chemical evolution.
The fate of the Universe is clear: it will go into dilution, with neighbouring regions getting further and further apart, stars dying. Small pockets of the Universe will continue their "life" – a permanent fight against entropy.