Lamarck theory: how do you explain the evolution of species?

Do you know what evolution is in biology? All species, including the human species, have evolved over the years and generations.

Two naturalists and scientists were the most prominent figures who tried to explain evolution: Jean-Baptiste de Lamarck Y Charles Darwin.

In this article we will talk about Lamarck's Theory, and how he tried to explain the evolution of species. This theory is called Lamarckism. We will know the characteristics of him, an example of it, and we will also see how, with the arrival of Darwin's theory, his theory falters until it is rejected.

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Lamarck theory: how does the evolution of species occur?

When we think of theories of evolution, Charles Darwin, an English scientist and naturalist, and a key figure in understanding the evolution of species comes to mind. However, before him, other scientists made his contributions to this field.

One of them was Lamarck (1744-1829), the full name of which is Monet de Lamarck's Jean-Baptiste-Pierre-Antoine (1744-1829); he is also known, but, as Chevalier de Lamarck. This author, also a naturalist, and this time of French origin, studied physics, medicine and meteorology.

Lamarck is known for his evolutionary theory of species, commonly known as "Lamarckism.". This theory is developed in one of his works: "Philosophie Zoologigue", which was published in 1809. Before explaining the theory of him, but, let's find out who Lamarck was.

Jean-Baptiste de Lamarck: who was it?

Jean-Baptiste de Lamarck was a French naturalist, who was born in 1744 and died in 1829him, at the age of 85. Lamarck was the one who coined the term "biology" in 1802.

One of Lamarck's greatest contributions was the separation of biology and religion; At that time, biology was heavily influenced by religion, and God was believed to be involved in many biological processes.

In Lamarck's theory, God has no role in evolution, and it is based solely on rational and scientific explanations of the time. Lamarck, moreover, was the first to formulate a theory of biological evolution, and was the founder of invertebrate paleontology.

But what does Lamarck's theory say, and how does it explain the evolution of species? Let's see it next.

Lamarck's theory: its two pillars

Lamarck's theory is based on two basic pillars: the first refers to the concept of evolution; according to Lamarck, living beings evolve naturally, since it is a characteristic that is part of us. In addition, we do it in an increasingly complex way, that is, we are improving our conditions.

The second pillar of Lamarck's theory has to do with a principle called "of use and disuse"; This principle holds that what species do not use in their day to day, ends up atrophying, and that what they use frequently, develops and improves; These developing conditions are also transmitted from generation to generation, that is, they are inherited.

Let's take an example to illustrate this: according to this theory, giraffes have progressively lengthened their necks because on some occasion they used it to get food from the trees; After making this gesture so much (stretching the neck), their necks have been lengthening, and the following generations of giraffes are born with their necks a little longer than the previous ones. That is, the function is perfected and affects the development of a physical characteristic.

In this way, what Lamarck's principle of use and disuse says is that the different members of the species (as well as their organs and other features) that are most commonly used develop and refine over time (and are passed on to the next generations). That is, the acquired characteristics are inherited.

Other elements of the theory

Lamarck's theory, in addition, held that living beings had evolved to complex forms, from simple forms. Lamarck also defended the great ability to adapt to the environment that living beings had.

Changes and new needs appeared in these environments, and the demands of the environment sometimes required animals to adapt through new mechanisms and characteristics.

These new needs and demands of the environment, required, in turn, adaptations and new characteristics in living beings. These new features, as we have seen, would prevail and be passed down from generation to generation (through inheritance), according to Lamarck's theory.

The arrival of Charles Darwin

Lamarck's theory was accepted by many, and it prevailed for a time. However, Charles Darwin arrived with his evolutionary theory, developed in the 1859 work entitled "The Origin of Species." Charles Darwin's theory completely revolutionized the scientific landscape of the time, since it greatly contradicted Lamarck's theory.

According to Darwin's theory, the evolution of species happens through a process of natural selection, and not by the use or misuse of certain members or characteristics of the species.

That is, according to Darwin, certain small modifications appeared in living beings in a random and random way; If these modifications happened to be more adaptive (suitable) than others for the living being in that particular environment, they would survive and be transmitted from generation to generation. That is, what allows us to survive is transmitted.

To this day, natural selection continues to be accepted by the scientific community, and explains the origin of the evolution of species. A) Yes, Lamarck's theory was superseded at the time, and is currently rejected.

Similarities between the two theories

However, although Lamarck's theory and Darwin's theory differ in their central explanation of evolution, they do share one point in common: both Theories affirm that the characteristics are transmitted from generation to generation (from parents to their descendants), and that these improve with age. weather.

Thus, Lamarck's theory, which is currently considered invalid, is correct in the aspect that we comment on the transmission and improvement of the characteristics. However, its central approach was not correct, and that is why it was not sufficiently accepted in the scientific community (and more so with the arrival of Darwin's theory).

To this day, as we said, Darwin's theory is the accepted one and the one that prevails; however, it currently receives another name: "Synthetic Theory of Evolution."

Bibliographic references

• Collado, S. (2009). Theory of Evolution. On-line philosophical encyclopedia.

• Fontdevila, A. and Moya, A. (2003). Evolution: origin, adaptation and divergence of species. Synthesis, Madrid.

• Gutiérrez, A. (2004). Evolution in the classroom: a reductionist synthesis. Research at School Magazine, 52, 45-55.

• Lessa, E.P. (nineteen ninety six). Darwin vs Lamarck. March Notebooks.