_Darwin: The Life’s trick

Darwin discovered the trick of Nature: bet on all the possibilities and then, and then eliminate the unsuccessful tickets. So he always wins; and life makes its way.

Samurai crabs

Heike crabs from Japan show in their shell the angry face of a samurai warrior. When a fisherman catches one of these crabs in their nets, he returns it to the sea out of respect or perhaps for fear of his fierce revenge.

And it is that in 1185 in the bay of Dano Ura there was a terrible battle in which many Heike samurai buried in the sea died. Together with his six-year-old emperor-boy, drowned by his grandmother when he saw the battle lost. Fishermen in the area say that these samurai still walk along the bottom of the sea with the appearance of crabs.

cangrejo samurayCarl Sagan, explained in the TV series «Cosmos», that for centuries, every fisherman who returned a crab with a human face to the sea, facilitated the reproduction of that type of crab. The fishermen created – without knowing it – a variant of the species. By selecting them, they themselves acted as a biological environment to which the crabs adapted.

What did this particular crab do to adapt? He swims. It was the fisherman who returned it to the sea, who rewarded the crab and its offspring because it reminded him of a samurai.

Artificial selection: the wolf turned into a dog

Twenty thousand years ago, our ancestors in Europe became friends with some jackals, or adopted wolf pups. This was a new environment for these animals, who assumed the leadership of a human as alpha male. It is what we know as artificial selection. This was a true intelligent design, because it responded to a useful and conscious purpose of human beings: for the dog and his descendants to serve as security guards, hunting helpers, pets or pets.

Artificial selection is also applied, from the beginning of agriculture, to modify plants and animals in the food industry. By selecting the best specimens for reproduction, the evolution of that species in a given direction is being influenced.

Let’s look at the similarity this has with what is described in the first three chapters of this essay (1), about the construction of the first tools by hominins.

The stone, in the left hand, presents a set of undetermined possibilities. The action on the right of the hand that the firing pin takes, determines those possibilities, denying some and allowing others. The result is something abstract and concrete: the cut materialized in the new tool.

Not that it is a design (yet), but an experimental result. Awareness and knowledge of what happened would come later, by socially sharing the experience with other group members.

But from the first time it is a determination, that is: a denial and at the same time an affirmation; That is a selection. When returning a crab to the sea, the fisherman is opting (whether he knows it or not, he is indifferent): he chooses to allow that edible crab not to die before transmitting his samurai face to his offspring. By deciding not to eat a fruit but to bury its seed, the farmer is also making its reproduction “one hundred and one” possible.

Knowledge of evolution in ancient times

Also the idea that everything changes and evolves is subject to evolution: it was already in the teachings of Heraclitus in ancient Greece. However, that dialectical thought (2), declined from Parmenides, replaced by the idea that Being is eternal and immutable. The static new idea became the foundation of metaphysical philosophy. Plato – and his disciples like Aristotle – argued that abstract ideas exist by themselves, (“meta-physics”) above bodies in particular.

According to this false belief, the existence of horses would depend on an idea of ​​a horse that is beyond any particular horse and beyond the idea of ​​any mortal. The idea would never change, because, it was believed: the being is what it is.

That idea about ideas remained in Greek philosophy and from there went on to the theology of the three religions of the West. But after the Renaissance, old ideas were increasingly criticized and a new way of thinking broke through.

In the modern age

As Kepler(3) discovered in spite of himself, the perfection of an idea does not make it more real. An ideal circle is “perfect” as an idea, but that does not imply that the orbits of the planets must be circular. In fact they are elliptical; which does not mean that an ellipse is less perfect than a circle.

The sciences do not deal with perfection or imperfection, but rather find general laws drawn from the observation of particular events, which explain in a general way the phenomena that occur in reality.

Attentive and unprejudiced observation of plants and animals, led various thinkers, since the Renaissance, to consider that living beings, different in their forms and abilities, had much in common, and that that varied over generations.

The ancient idea of ​​evolution returned timidly again and again. And since the seventeenth century, with the gradual loss of power of the Roman Church, he returned blatantly, especially in France and England, of the pen of enlightened thinkers.

In 1731 Linnaeus (Sweden 1707-1778) published Systema Naturae, with the first classification of living beings, differentiated into genera and species.

In 1749 the count of Buffon (France 1707-1788) edited while he lived 15 volumes of general and particular natural history. He believed in the variation of species over time, but not in the current sense of evolution, but as degeneration. For example, he believed that the monkey was a degeneration of man.

In 1800 Lamarck (France 1744-1829) outlined his first ideas on the evolution of life and in 1808 he published his book Zoological Philosophy, with a theory on the evolution of species. That same year Charles Darwin was born.

Alfred Russel Wallace (GB 1823-1913) proposed in an essay, which he sent to Darwin, a theory of evolution based on natural selection. This decided Darwin to publish his own theory in 1859, in which he had been working for many years.

Darwin: his journey of the Beagle

Charles Darwin (GB 1809-1882). From a young age was very interested in observing nature, especially the small forms of life.

That interest was rewarded at 22, when Darwin was invited to a trip of almost 5 years, around the world in the oceanographic ship Beagle. In it he made systematic observations, both of geological movements, at the beginning of his trip through the Atlantic of South America, where he verified the existence of fossils on the summit of mountains emerged from the sea.

He also observed vegetation and fauna, especially in the Galapagos Islands on the American coast of the South Pacific. During his stop on those islands he saw the differences between the turtles that inhabited the different islands. Despite their proximity, those islands constituted separate ecosystems that had differentiated turtles in a few centuries, as evidenced by their comparison with the remains found.

At the subsequent stop in the Pacific atolls, he observed an ecosystem evolving live within the same atoll.

He took advantage of the long journey around the world to England, to carefully compare the pieces collected, noting the small differences in the beaks of the birds that would take him in the following years to establish his theory.

The long trip gave him the opportunity to observe the habits of similar species, geographically separated. For example, he observed that the vegetation of the High Alps resembles that of the polar regions, from which he deduced a common lineage in times of the ice age. One of his best works refers to what is currently called ecology; that is, to the geographical distribution of species and genera.

In 1838 he conceived his theory of natural selection.

In 1859 he published “The origin of the species through natural selection, or the preservation of the preferred races in the struggle for life.”

In 1871 he published “The origin of man and selection in relation to sex.”

Why is Darwin so important?

Darwin did not invent the evolution hypothesis. But its importance lies in having convinced biologists and the educated public of the general fact of evolution. His writings, contrary to Aristotle, led to abandoning the ancient belief in the immutability of the species and accepting the view that the various genera of animals have developed by variations from a common lineage.

Above the old image of a static universe, perfectly formed from its distant beginnings, the “time” dimension appears with evolution as a principal actor, since change is the essential and the static does not exist. The dialectic of Heraclitus now reappears in life: that it is the same but not the same, over billions of years.

Mendel’s laws

Darwin did not know the studies of his contemporary, Augustinian monk Gregorio Mendel (Austria 1822-1884), founder of scientific genetics and the concept of gene for separate hereditary entities.

Although he published a work with his discoveries, his work was not valued until 1900, which is also when what Mendel called “elements” began to be known as genes. Darwin had died before, in 1882.

Nor did Freud know about these discoveries, which would have avoided some of his own mistakes about individual adaptation to the environment.

None of them lived anymore when DNA was discovered in 1953.

Scientific research on the evolution of species still has a long way to go. And as it progresses, it begins to discover possibilities of action on living beings that call into question all the limits we know, including ethical ones. This chapter could be considered only a humble introduction.

Next chapter: Neuroscience: brain and mindNeuroscience: brain and mind.
Neurosciences study the mind as a result of brain activity.

See Chapter index


Current chapter NOTES

(1) See these three chapters on the construction of the first tools:

– When the stones came aliveWhen the stones came alive…
…the hands began to build the human being.

– Pragnanz in the left handPragnanz in the left hand
The left hand was humanized, making it easy to feel what was hidden when building a tool.

– Determination on the right handDetermination on the right hand
The right hand rationalized itself, by determining the possibilities presented by the left hand.

(2) See: Dialectical or metaphysical thinking?

(3) See: Experimental science, modern thinking

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