Evolution for Vacations: Everything I Misunderstood About Darwin and Species | Sciences

The beach is a good place to reflect on the evolution of life on Earth. If you leave your prime position in the hammock and take a walk, you will be able to observe the low-flying seagulls, children searching for crabs, petunias, anemones, and sea urchins among the rocks. Beachy summer brings us closer to massive biodiversity without much effort. Face a lot of sticky bug and primitive, we can conclude that evolution is undoubtedly a process of permanent improvement through which more complex and perfect forms of life emerge: from anemones, through worms that fishermen use in the afternoon, clams, crabs, sea urchins, fish, seagulls, etc. . At one point, this whole process gave rise to mammals, which later led to readers in their hammocks. Does not our technological development demonstrate the evolutionary superiority of the human race? Thinking this way is not your fault. This idea is still taught in schools and even in some natural history museums. My only goal today is to convince you that evolution doesn’t work that way. It is not progressive and no life forms are higher than others.

The common notion is that evolution is constantly pushing life forms toward complexity Jean Baptiste Lamarcka French naturalist who lived between 1744 and 1829. Many of us have heard the tale of Lamarck’s giraffe, which Strive to reach the top of the sheets They end up with longer legs and necks, traits inherited from their offspring, who continue to reproduce this trend. The example of a giraffe and this process is known as inheritance of acquired traitsToday, it is still used almost in schools for ridicule Lamarck’s theory. Who comes up with such a ridiculous theory! But the tale of the giraffe barely occupies four lines in Lamarck’s work, and the inheritance of acquired characters was the popular thought of the time. The flesh of Lamarck’s evolutionary theory, considered the first modern evolutionary synthesis, was not in these adaptations, but in what he called Tendency to complex. Lamarck believed that the basic process of evolution was constantly working and directing life forms toward more and more complex levels of organization. As a result of the mysterious interactions of the biocomplexes, body membranes tend to flex more and more, producing more and more complex structures. Increasing complexity does not require environmental changes or adaptation, it is simply inevitable. This is why theories that postulate the existence of an internal force or a pre-programmed process in evolution are named lamarkists.

We can imagine the Lamarcian system as a large commercial building. Life begins in the deepest parking lot (such as car park-3), with single-celled organisms already on the escalator. Inevitably, they will rise from floor to floor, gradually increasing in complexity, evolving into anemones (parking-2), worms (parking-1), etc. Upstairs, upstairs, are mammals, including readers in their hammocks, of course. But how does it happen that if everything gets too complicated, we keep seeing anemones, polyps, and worms in the rocks? Because in parking lot-3 life comes up through autogenesis over and over again, so what we actually see are several processes moving upstairs.

The neck and the invisible

What about the famous giraffe? As a secondary process, organisms of a certain level vary on each floor. They break off the escalators and move through different sections of that floor. This second type of development occurs in response to environmental changes, i.e. Adaptation To the infinity of circumstances that life faces. Here comes Lamarck’s giraffe, which is nothing more than a drift within the mammalian floor. But for Lamarck, these ramifications were not only of little importance, but also anomalies and distortions that made it difficult to study what was really important. The real essence and mystery was in the escalators, which were unfortunately the result of incomprehensible chemicals that were too far out to be studied. Lamarck was revolutionary because he explained all life on Earth through only two evolutionary processes, unlike previous ideas that were either based on theological assumptions or rejected evolution outright (or Transformation, as was said at the time). However, Lamarck’s ideas came to say, as some historians summarize, that what is important in evolution cannot be seen, and what can be seen (the neck of the giraffe) is irrelevant, which judges the empiricists of evolution to be irrelevant.

Although Lamarck and his theory have received various criticisms, he has been Charles R Darwin who presented in 1859 an evolutionary theory that would deconstruct the evolutionary scale, the hierarchy of levels of complexity and Lamarck’s concept of biological progression. Instead of two separate processes to explain evolution, Darwin needed only one: natural selection. In this sense, both theories invoke simple operations to explain highly complex systems, a characteristic shorthand of modern science. natural selection (Only the fittest live to produce offspring) As a mechanism of adaptation to the environment, it produces gradual and gradual changes, imperceptible from generation to generation, but accumulating over millions of years.

Darwin himself succumbed to these influences and gave a preponderant role to competition among living things.

As you can see, Darwin did not invent the concept of evolution, not even the concept of adaptation. Nevertheless, Darwin was a revolutionary. First, because it positions natural selection as the dominant process mechanism of evolution whose implications are obvious and we can study, laying the foundations for evolutionary biology. Second, because it knocks on the ground The rule upon which the human race is based, because his theory explains how all species are descended from others. We have another twig from a huge tree. There are no escalators or levels. In its purest form, natural selection does not offer an absolute and sustainable process of improvement, but only an adaptive improvement in relation to immediate conditions, which change erratically. What is the day adapted to betterTomorrow does not have to be. In 1872 Darwin wrote a letter to paleontologist Alphus Hyatt: “After much thought, I cannot escape the conviction that there is no innate tendency toward progress in evolution.”

But we humans have a hard time visualizing stories that lead to nothing. In the Victorian era, from the great technological advances and conquests, it was difficult to avoid the concepts of progress and superiority when talking about the history of civilizations or technology. What is the evolutionary history but history? Darwin himself succumbed to these influences, and in his “struggle for survival” he gave competition between organisms a weighted role in adaptation to the changing environment. Thus, the winners of this perpetual competitive battle could not be anything but to be superior to the vanquished. As a result, in his work Origin of Species There are many reflections that point to the continuous improvement and progress in the forms of living.

All too often we hear that mass extinctions clean up the ecosystems of the worst-adapted species, but it’s colossal stupidity

Therefore, although Darwin discontinued the ideas of scales and levels of perfection, he did not completely close the door to the idea of ​​continuous evolutionary progress, which has persisted to this day. Take, for example, the idea of ​​progress in our evolution. Today we know that human evolution must be represented as a tree with about 30 branches, Known types of human ancestors. But the common notion of human evolution is one that ends with it sane man. It is easier to understand evolution as a linear path than to see it as a forest. And while Forest speaks of a breed that once had great diversity lost, the Linear Path sets us up as the end result of continuous improvement, a much more comforting narrative.

In the second half of the twentieth century, paleontology finally allowed us to move previous notions of progress in evolution. Fossils have taught us that life is constantly affected by unpredictable environmental changes and that, from time to time, it collapses dramatically due to mass extinctions. When we span time dimensions measured in many millions of years, accidental events and serendipity take over. In a game with changing rules, the importance of competition between organisms falls to the background. Although we often hear that mass extinctions cleanse the ecosystems of the worst-adapted species, this is sheer stupidity. Species cannot adapt to something they have not experienced before, such as an asteroid impact or a massive volcanic eruption that changes the climate over tens of thousands of years. Today we know that the survivors of this kind of catastrophe are a lucky handful of species.

If there is a catastrophic extinction tomorrow, there is no reason to believe that the human race will have a better chance of surviving than anemones or sea urchins (which, incidentally, have been on this planet for much longer than we have). It will depend on the lottery: on the nature of the disaster it is impossible to predict a priori. Therefore, in evolution, we must avoid the ideas of progress, improvement and progress, where conditions change volatilely and the Great Extinction restores life on Earth from a few lucky survivors.

Juan Lopez Cantalapedra Paleontologist and researcher at the University of Alcala

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