One of the issues present in contemporary society is the problem of understanding of the origin of the species. For a long time, the scholars of all ages have been trying to investigate the patterns of the development of living organisms on the planet. Although there are still different opinions regarding these processes, one regards the theory of evolution scientifically reliable. Its first theoretical assumptions appeared several centuries ago. However, it took time to investigate their validity due to the need for progress of the technology and knowledge. Consequently, the modern theory of evolution is a comprehensive pattern arguing with the development of the living beings in the course of history. The paper discusses the postulates of the theory of evolution through the evaluation of the concepts presented in Jerry Coyne’s book Why Evolution is True. It generalizes and criticizes the author’s ideas to bring one’s scientific understanding of the issue. Thus, the paper presumes that evolution is a comprehensive and scientifically reliable theory that describes the evolvement and development of the species.
What is Evolution?
First, it should be said that the living organisms of our environment seem to be designed to perform their functions perfectly. This fact has been raising long discussions of theologians and philosophers of the appearance of the designer that had introduced such a perfect natural system. However, the only opinion that people have regarded valid for ages was God’s manifestation through such creations. Apparently, the idea presented by the natural theologians supports this theory even now. For instance, Coyne argues that they described nature and “believed that they were cataloging … the identity of God manifested in its well-designed creatures.” However, some people doubted this idea and searched for more rational ways to explain the state of things in the natural world. One of the scholars who had his personal answer to this question was Charles Darwin. Thus, demonstrating his scientific curiosity in 1859, he stated, “We see beautiful adaptations ... in every part of the organic world”. Moreover, the scientist rejected the ideas of conscious design and applied purely scientific approach, relying on the objective evidence. Apparently, Darwin was among the first scientists who completely rejected any theological assumptions regarding evolution. Consequently, his view was that evolution “results from the fixation of useful individual variations provoked by the struggle for existence under the influence of natural selection”. Furthermore, one should consider the fact that evolution may take hundreds, thousands, or millions of generations. The reason for this is that the genetic changes reflecting the shift of any biological quality of the species evolve gradually. If some organisms have a short lifespan, there is a possibility for them to undergo the evolutional processes quickly. The example may be the populations of microbes, some of which live for approximately twenty minutes. However, the greater changes such as the change of bones, body parts, and so on require much more time. Moreover, some of the species may undergo evolution faster, whereas others experience its slow tempo. Such speed depends on the aggressiveness of the environment and the need for adaptation. Thus, if natural selection is active, the changes of the characteristics of the species go faster. At the same time, if the natural surrounding is stable and there is no need for changes, the evolution slows down. The biologists call these characteristics and principles of the changes the idea of “gradualism”.
Furthermore, scholars assume that any species has a single ancestor. The reason for this is that the variety of the living beings shares common features. Such features are the principles of the production of biochemical energy, four-letter DNA code, and its transcription into proteins, and so on. At the same time, all the species bear completely different features that indicate the existence of the principle of speciation. According to it, the descendants of the species may follow their path of development. In case evolution takes millions of years, the difference between the appearance of the ancestors and descendants may be drastic (Figure 1). Although there are claims that there are “missing links” between the entirely different species, archeologists find fossils that indicate such connections.
Figure 1. The difference of the ancestor and descendant species during the evolution. X and Y are the species that were common ancestors between later-evolved forms.
For instance, Sample reports that the fossils found in Georgia indicate the existence of the transitional kind between the human species. Thus, he claims: “The remains at Dmanisi are thought to be early forms of Homo erectus, the first of our relatives to have body proportions like a modern human”. Therefore, the assumption that closely related species have a common ancestor is scientifically valid. The only question is whether it is possible to find the fossils of the transitional kinds that are in a condition appropriate for the analysis. That is why the statement of the common ancestry in evolution indicates that it is possible to find the links between the ancestors and descendants. The two mostly reliable methods for that are the DNA and fossil analysis. One factor that adds to evolution is a mutation. However, it is a minor factor of alternations that roughly ever contribute to the development of the species. Thus, Coyne indicates that “mutation are changes in traits that already exist; they almost never create brand-new features.”
Next, one of the factors that contribute to the process of evolution is natural selection. However, it does not indicate that the evolved traits in the species are perfect. The result of the natural selection is the adaptation of the species to the aggressive factors of the environment. The example of it might be the case reported by BBC in 2006. Scientists discovered an enclosed cave system in Israel. It has a lake, but it has been sealed from the outer world. Moreover, the ecosystem “is thought to date back millions of years to a time when the area was part of Mediterranean Sea”. Consequently, scientists found the species that had undergone the evolutional processes in the described ecosystem. Thus, the species were eight blind white-colored crustaceans adapted to sea and fresh water (Figure 2). As one can see, evolution led to the fact that the species had lost their eyes and color adapting to the dark environment.
Figure 2. The crustacean found in Israel.
At the same time, there are many other opinions and speculations on the subject of the theory of evolution. For instance, Coyne indicates that there was a time when biologists thought the “inner drive” leads evolution apart from natural selection. Additionally, there is a group of people that highlights the word “theory”, attempting to indicate that there is no complete approval of it. Such attempts aim at undermining its scientific validity. For instance, a president candidate Ronald Reagan stated in 1980, “It is a scientific theory only… and is not yet believed … as it one was”. Such statements speculate on the term “theory” and tend to degrade its meaning from the scientific to casual one. However, the scientific theory is not only the description of the state of things but the complete explanation of the contributing factors and their correlation. Additionally, a scientific theory must be testable and make verifiable predictions. Thus, the explored observations of any theory should be proved or disproved. Some decades ago, there was more theoretical evidence of the theory of evolution. However, the advances of the contemporary science have made deep practical investigations available to support the validity of evolution.
Why Evolution is True
One of the most important aspects that supply the evolutional studies is archeology. In this sense, fossils are a priceless material that helps biologists and archeologists to restore the past and fill the holes in the evolutional knowledge. However, collecting them often involves various obstacles. Thus, Coyne argues that his colleague faced political troubles, bandits, and disease despite the danger of the desert when finding the new species of dinosaurs. The discovered species influenced the views on the evolution of dinosaurs. However, the described problems show that the society does not value the scientific contribution of archeologists. Many paleontologists risk their lives to introduce great scientific discoveries as they have problems with law and criminals at the same time. The statistics indicates that people have discovered 250,000 different fossil species. However, current fossil evidence is about 1 percent of all species. Modern means of the fossil analysis allow precise dating of the remnants, which allows creating a historical timeline of the existing species. For instance, scientists use the radioactive analysis of the rocks to specify the date of the formation of the fossil. However, it takes too much effort for the archeologists to collect fossils in different countries. That is why there is a strong need in the social support of the archeological studies since they provide historical evidence. Consequently, there is a need for a legal support of archeologists in any country because of the significance of their discoveries.
Additionally, the development of the molecular sciences gave scholars the possibility for precise evaluation and analysis of the fossils as well as the present day organisms. Thus, the humanity has information from DNA and protein sequences that informs of the evolutional relationship between species as well as the approximate times of their existence. Consequently, the linear changes of the DNA sequences prove the evolution of certain species from their single ancestor. Coyne identifies this method as “molecular clock” that can be used for the estimation of the divergence times of species that have proof fossil records. Additionally, this information blended with the modern knowledge of the geography allows identifying the relationship between the species from different continents.
Figure 3. The breakup of Pangaea (Ghose, 2014).
Thus, society knows that about 300 million years ago Earth did not have several continents but the single one called Pangaea. Therefore, the ancient species lived on a single continent that had gradually broken up. Moreover, the separation consisted of the several stages. First, Gondwana (current Africa, South America, Antarctica, India and Australia) split from Laurasia (Eurasia and North America) 200 million years ago. Later on, Gondwana broke up about 150 million years ago. Consequently, the breakup resulted in the separation of the ecosystems that influenced the evolution of various species. Likewise, the ecosystems also have been changing and separating for millions of years. This fact supports the DNA evidence, explaining the existence of a single ancestor living on a single continent several hundred million years ago.
An additional factor supporting evolution is a sexual selection through competition. One can observe it in the wildlife, which guards it from misunderstanding or speculations of theologists and philosophers. The key features of this idea are the direct competition between males for the female and the female’s selection of the possible mates. Thus, selection favors any feature that promotes the victory between direct clashes of male representatives of the species. At the same time, the second factor stimulates changing the appearance of males to attract their partners. Consequently, the evolution stimulates the development of the “armory” such as claws, body size and “ornaments” such as brighter feathers, bowers, and so on. The second factor rises from the evidence that female representatives constantly choose their male mates. Thus, males enter the competition of attractiveness. Discussing the examples from wildlife, one may describe plants or birds. Thus, plants have flowers of different colors. The reason for this is that bright colors attract more insects assisting reproduction of plants. As a result, plants with darker colors and absence of attracting smell reproduce less, which leads to the evolutional decay of the dark colored plants. Additionally, in blackbirds, song and plumage help males in attracting more mates, which results in “non-talented” birds losing mates and reproduction ability. Furthermore, one should mention the role of the postmating competition in species. Its role is in preserving the quality of the “descendants” through the restriction of access to the female for other males. The example of this can be the case introduced by Coyne when a Central American millipede male rides a female for several days after fertilizing her, preventing any competitor from claiming her eggs. Thus, the evolution has a variety of methods to assure the appearance of the new species, their development, adaptation, and reproduction. The only question is whether society is capable of its acceptance.
Thus, there is evidence that society still either rejects or doubts the validity of evolution. For instance, the recent survey with the question of agreement or disagreement with its probability revealed 40% of Americans’ agreement, 39% disagreement, and 21% uncertainty. In contrast, such countries as Iceland, Denmark, France, and others showed more than 70% agreement. Thus, Americans slowly accept the idea of evolution. One of the possible reasons could be extreme religiosity of the country. Additionally, such theories as creationism attempt to blend religion with science, introducing the religious methods of knowledge into science. Such approaches are inappropriate because the scientific toolkits rely on objective investigations apart from the pure belief. Likewise, Coyne stresses, “the best strategy to make Americans more receptive to evolution might require loosening the grip of religion on our country.” In this perspective, there is a strong need for the social interest to knowledge and scientific methods of cognition. To complete this, the authorities and scientists should popularize biology and other sciences as well as raise the social interest in them. In this case, society would benefit from the scientific knowledge.
Summarizing the discussed information, one concludes that the theory of evolution is one of the most significant scientific theories. It explains the origin of the species in the living world as well as their relations, development, and historical changes. Moreover, it allows the humanity to explore the existing species and their ancestors. The advances of molecular biology, geology, and geography enrich and support the theory of evolution with different evidence. Thus, scientists have discovered that many species had a single ancestor living on a single continent hundreds of millions years ago. However, one should stress the fact that society is only partially ready for the acceptance of such scientific theories. The reason for this is that the religious institutions and people reject the theory of evolution because of their religious beliefs. Likewise, some scholars attempt to blend religion and science, introducing such theories as creationism. Thus, there is a strong need for raisin the scientific awareness of the society to allow people think more rationally and accept the discovered scientific evidence.