The modern theory of evolution is a synthetic science based on Darwin’s doctrine of the origin of life, the emergence of a variety of living nature, adaptation and expediency in living organisms, the origin of man, as well as the emergence of breeds and varieties. Modern Darwinism is often called Neo-Darwinism, which is supplemented by information from other biological sciences, primarily genetics, as well as ecology, molecular biology, taxonomy, and others.
It represents the theoretical foundation of biology that takes evolutionary theory as a guiding principle. Individual biological sciences differ both in the objects of research and in the complex of the studied problems. Many problems investigated by the special sciences are of general biological significance, but no science can replace Darwinism, the evolutionary theory. This paper aims to analyze the modern evolutionary theory and explain how evolution works.
The History of Evolutionary Theory’s Development
Long before Charles Darwin, the attention of scientists was attracted by the existing variety of living organisms, structural and functional similarities between them, as well as differences associated with the way of life. They put forward various hypotheses and as the facts accumulated, the ideas evolved. These views of ancient scientists can also be represented in the form of stepwise evolution since the formation of basic concepts, terms, and the science itself developed gradually. The history of evolutionary doctrine before the publication of Charles Darwin’s works is usually called the pre-Darwinian period (“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video” 2014).
It consists of several important stages, which in turn influenced the development of science and the views of Darwin. The ideas of the changeability of the organic world have found their supporters since ancient times. Aristotle, Heraclitus, Democritus, and several other ancient thinkers expressed these thoughts. In the 18th century, Carl Linnaeus created an artificial system of nature, in which the species was recognized as the smallest systematic unit (“Biological Anthropology/Unit 1: Evolutionary Theory/Darwinian Evolution – WikiEducator,” n.d.). He introduced the binary nomenclature of double species names, which made it possible to systematize the organisms by taxonomic groups.
The creator of the first evolutionary theory was Jean-Baptiste Lamarck. He recognized the variability of species, thereby indirectly refuting the divine creation of life. However, his assertions about the expediency and usefulness of any emerging adaptations in organisms, the recognition of their desire for progress as the driving force of evolution, have not been confirmed by subsequent scientific research (“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video” 2014). Also, they did not find their confirmation of Lamarck’s position on the inheritance of characteristics by an individual and on the influence of exercises on the adaptive development of organs. The main problem that had to be solved was the problem of the formation of new species adapted to environmental conditions.
Darwin was the first to propose a clear mechanism of evolution, and his idea was quite simple. According to the natural selection, the generation of descendants of living things is more numerous than the generation of parents, which leads to competition for resources and the struggle for existence. There is heredity whereby survivors of the struggle for existence can pass on their characteristics to descendants, and for this reason natural selection takes place.
Variability changes heredity, and for this reason all new forms are drawn into natural selection, so that evolution takes place. Evolution changes the indicators of natural selection, as well as the degree of heritability and variability (“Biological Anthropology/Unit 1: Evolutionary Theory/Darwinian Evolution – WikiEducator,” n.d.). Darwin’s theory of evolution is the answer to an ancient question in the form in which the era, that is, the middle of the 19th century, could have taken it. By this time, several significant evolutionary concepts have been known, but they have not attracted a proper attention. However, a new theory spoke about evolution in terms of cause-and-effect relations and showed its mechanism.
The Idea of Evolution as a Change in Traits
Charles Darwin’s historical merit is not only the proof of the origin of human from ape-like ancestors but the creation of the first natural science theory of evolution, which explains the mechanism of evolutionary changes. The core of Darwin’s theory of natural selection is the proof of the hereditary heterogeneity or variability of individuals of any species, each of which produces an excess number of offspring, which can survive and begin to reproduce.
However, neither Lamarck nor Darwin used the term “evolution” in the sense in which it is used today. What is now called evolution, Darwin called the variation of offspring (“Biological Anthropology/Unit 1: Evolutionary Theory/Darwinian Evolution – WikiEducator,” n.d.). In other words, evolution is a transformation of the form and way of life of organisms, as a result of which descendants acquire features that distinguish them from their ancestors. Today, the genetic aspect of variation is highlighted and emphasized.
At the same time, the existing ideas about evolution were formed when nothing was known about genes. They were born and developed due to the need to explain the observed diversity of living organisms. Thus, evolution was understood as changes in traits, primarily morphological, in the course of generations. It is no coincidence that Darwin saw the main task in understanding how species occur. With the emergence of genetics, it became possible to delve deeper into the essence of changes in traits and link genetic changes with the observed diversity of living organisms in space and time (“Experiments Explained: Clear and Simple! Learn the Basics” n.d.).
The study of the diversity of morphological and other traits of phenotypes has been and remains one of the main tasks of evolutionary biology. The solution of this task is a necessary condition for further penetration into the essence of the evolutionary process, revealing its mechanism.
The main concept used in the study of phenotypes is trait, and as one would expect, there is no consensus on the question of what to call a trait. This question was posed and considered almost exclusively in connection with the tasks of taxonomy, and therefore the terms “character” and “taxonomic character” were used as synonyms. A trait is a feature of a member of a given population or taxon, by which it differs from a member of another population or taxon. More importantly, if a trait is a characteristic that varies from organism to organism or from group to group, then one and the same characteristic may in one case be, and in the other not be a trait (“DNA, Chromosomes, Genes, and Traits: An Intro to Heredity” 2017).
For example, the number of chambers of the heart cannot be considered a feature of a mammal as long as it is compared with other mammals, but it is a feature if a mammal is compared with reptiles or fish. Another important characteristic of a trait is variation within wide or narrow limits. Thus, Darwin spoke about the discrepancies in characters between parents and descendants, which ultimately ensures the evolution of organisms.
Synthetic Theory of Evolution
Many features and patterns of the evolutionary process described by Darwin could not be fully explained by him due to the insufficient development of sciences at that time. This served as the basis for well-founded criticism of evolutionary theory. For example, any change that has arisen in one individual gradually dissolves as a result of crossing and, therefore, cannot gain a foothold as a result of the struggle for existence. Darwin and his followers could not give counter-arguments since they had little idea of the discrete nature of heredity.
The discoveries in the field of genetics, molecular biology, and population research have led to the fact that evolutionary theory has ceased to be a hypothesis but has been explained and largely proven. The mechanisms of evolution were revealed in more depth and the reasons for the change in the gene pool of the population were described. The role of DNA as the material basis of heredity and variability was discovered as well. In the synthetic theory of evolution, the population genetic approach occupies an important place (“DNA, Chromosomes, Genes, and Traits: An Intro to Heredity” 2017). It studies how the driving forces of evolution affect the change in allele frequencies in populations, the spatial structure of populations, and explains speciation. Evolution in the synthetic theory of evolution is considered as a gradual process of changing the gene pool of populations.
Significance of Evolutionary Theory
Thanks to the theory of evolution, biology has turned from a storehouse of facts into a true science capable of understanding causal relationships between phenomena. Moreover, the evolutional theory is the basis of natural selection. A typical example is the domestication of such species as the European polecat (Mustela putorius) and the appearance of its domesticated form – the ferret. It is also widely used in solving medical problems. The theory of evolution is important for people to understand the processes in nature, when organizing and carrying out environmental protection measures. The rapid change in the nature, caused by human activities, has posed the problem of preserving life on Earth (“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video” 2014).
Now, when it is realized that any measures for the development of natural systems should be preceded by an ecological justification, mankind will have to realize the need for an evolutionary analysis of the consequences of human intervention in natural objects and processes. The study of microevolutionary processes has revealed the value of the minimum numbers of populations. It has turned out that keeping a minimal number of individuals in a population inevitably leads to the its extinction due to closely related mating. The theory of evolution is also important for elucidating the reasons for the resistance of organisms to pesticides. The modern understanding of the evolution of living things makes it possible to improve genetic selection work to create new breeds and varieties.
Darwin’s theory is considered not only as a major biological discovery but also a model for several findings in other areas of knowledge. It clarifies the laws of the development of society, the history of mankind, and the development of language. Concepts similar to Darwinism have appeared in many fields of knowledge, for example, history, sociology, paleoanthropology, geology, psychology,and linguistics.
This is a natural process since various sciences deal with a certain wide variety of forms, and they are faced with the question of their development. Of all spheres of scientific knowledge, biology deals with the maximum diversity of objects, therefore, the issues related to diversity are most acute in the field of biological sciences (“Experiments Explained: Clear and Simple! Learn the Basics” n.d.). As a result, among the sciences dealing with the classification of forms, their comparison, and development, biological disciplines have achieved the greatest successes, for example, taxonomy, morphology, the theory of evolution, and others.
Relationship with Other Sciences
In the system of scientific knowledge, biology occupies an intermediate position between the natural and social disciplines. For example, evolutionism, not without the influence of biology, has spread in astronomy, chemistry, physics, geography, linguistics, ethnography, and other sciences. Biological concepts and constructions cause its resonance with physics, astronomy, chemistry, cybernetics, mathematics, geography, geology, economics, psychology, and many other natural sciences (“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video” 2014).
The unique features of each organism, each level of organization of living matter, and the organization of the human environment make biology related to the humanities and social sciences. Thus, it is related to philosophy and dialectics, history and social science, sociology and ethnography, philology and linguistics, ethics and management sciences.
The regularities of the formation of society and social development are easily projected into the structure and functioning of biosystems. Moreover, without a sociological conceptual apparatus, it is absolutely impossible to explain such biological phenomena as the hierarchy of living organisms, the social hierarchy of animal societies, the concept of an ecological niche, as well as the phenomena of migration and crossbreeding in genetics (“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video” 2014). All this is the methodological basis of a systematic approach that optimally reflects material, informational, and energy interactions between elements of living systems.
Therefore, considering the social and cultural analysis of the modern world on the basis of empirical examples, it becomes clear how social anthropology is related to biological. Anthropology is an academic discipline, the content of which is the study of a person from a biological, cultural, and social point of view, the search for generalizations about culture and human nature, a comparative analysis of the similarities and differences between cultures. Hence the basic principles of anthropology, such as universalism, holism, cultural relativism, the principles of consistency and integration, are related to the theory of evolution.
According to Darwin, the evolutionary process is determined by the conditions of existence and manifests itself in the formation of new, adapted to these conditions, individuals, species, and larger systematic taxa. The main evolutionary factors are hereditary variability and natural selection. The prerequisites for natural selection are an excessive reproductive potential, hereditary variability, and changing conditions of existence. It plays a creative role in evolution and is a consequence of the struggle for existence. The result of natural selection is the preservation of any adaptations that ensure the survival and reproduction of the offspring.
Charles Darwin revolutionized scientific thought by showing how evolution explains the biological complexity and amazing diversity of life on Earth. More recently, there has also been a growing interest in the social sciences in explaining human culture using Darwin’s theory. Having considered the vast material from culture to public policy, from the spread of religions to human behavior in economic markets, it can be argued that human culture is an evolutionary process that reveals the main Darwinian mechanisms: variability, competition, and inheritance.
“Biological Anthropology/Unit 1: Evolutionary Theory/Darwinian Evolution – WikiEducator.” n.d. Wikieducator. Web.
“DNA, Chromosomes, Genes, and Traits: An Intro to Heredity.” 2017. YouTube Video. Web.
“Experiments Explained: Clear and Simple! Learn the Basics.” n.d. youtube. Web.
“The Making of a Theory: Darwin, Wallace, and Natural Selection — HHMI BioInteractive Video.” 2014. YouTube Video. Web.