The origins and development of evolutionary theory: From Darwin to Dawkins, why is it the foundation of modern biology?

The theory of evolution originated in ancient Greece and was developed through Darwin and Dawkins. The theory explains the variation of heritable traits among populations of organisms and centers on four principles: natural selection, mutation, and environmental limitation.

 

Evolutionary theory in its broadest sense refers to a group of theories about evolution, which is simply the change in heritable traits among populations of organisms. When we talk about evolutionary theory, we’re usually talking about Darwin’s theory of evolution and beyond, but the idea that one kind of organism might have originated from another kind of organism has been around since ancient Greece. For example, philosophers like Empedocles (c.490 – c.430 BC) and Anaximander (c.610 – c.546 BC) were among the first to think about evolution. Thus, the idea of evolution itself predates Darwin.
After the philosophers of the ancient Greek era, the scientific approach to the study of species and their origins did not take place until the 17th century. The first modern theory of evolution was that of Lamarck (1744-1829), who argued that all living things develop gradually over generations towards increasingly more complete and complex forms. According to his theory, the simpler organisms that exist today have shorter origins. He argued that newly acquired traits, such as the development of muscles, are used or not used depending on whether they are suitable for the environment, and that these traits are passed on to offspring in the form of inheritance of acquired traits, but he failed to provide evidence for this, which has since been criticized. These and other theories of the gradual development of species, and their criticisms, gave rise to Darwin’s (1809-1882) theory of evolution, which is widely accepted today.
Darwin summarized his ideas about evolution in his famous Origin of Species (1859). His theory is the foundation and basis of modern evolutionary theory, and if we summarize the content of the Origin of Species, we can say that it has four main characteristics
First, all species have the reproductive capacity to reproduce themselves in some way. An example of this is that offspring can be born between species that are not genetically distant, such as a lion and a tiger, but the offspring is not recognized as a new species because it lacks the reproductive capacity. Therefore, we can say that self-replication is the first step in the process of evolution.
Secondly, during the process of replication, some kind of variation occurs, and this variation, such as mutations, results in significant differences between individuals. In other words, if self-replication in the first condition were always 100% perfect, there would be no evolutionary process. It is the imperfections of the self-replication process, the variables that we would normally expect to be avoided that can cause mutations in genes, that paradoxically allow evolution to occur. This means that the variation must be inherited in order to be used for evolution, which means that, for example, muscle acquired through acquired and continuous use is not inherited and therefore cannot serve as a variable for evolution, whereas variation in the DNA corresponding to the genetic code is likely to be inherited and therefore can be attributed to evolution.
Third, and more importantly, because resources are limited in the environment, there is competition for survival among individuals, with less adapted individuals having a lower chance of survival and more adapted individuals having a higher chance of survival. If there are enough resources in the environment for all individuals to survive unconditionally as they are born, then if there is no competition within a species, then both random mutations and unmutated individuals will survive, and the species as a whole will not change in any particular direction, but will simply have more varied forms. When there are only a few individuals in an environment, there is no need for competition between all individuals for the resources that are sufficient within a given environment, but after some time, when the species has saturated the ecosystem, competition within the species for limited resources becomes inevitable.
Finally, the fourth condition is that if a species has a better chance of surviving, it has a better chance of leaving more offspring in the next generation, and more individuals will be born with traits that favor that environment. This process is also known as survival of the fittest through natural selection, where individuals that are adapted to their environment have a better chance of surviving intra-species competition and therefore have a better chance of maturing to the point where they can reproduce, leaving many offspring with their mutations and genes. Of course, all of this is probabilistic, and even if the mutation gives only a slight survival advantage, we can predict that this increase in the average chance of survival will lead to a significantly higher number of individuals with the trait after many generations.
This process summarizes Darwin’s argument that over time, populations will adapt to their environment and change overall, and that these changes will accumulate over a very long period of time to form new species.
Darwin’s theory of evolution evolved and today, combined with Mendelian inheritance, a form of evolutionary theory called Neo-Darwinism is considered orthodox. It was proposed by August Weismann (1834-1914), who refuted Lamarck’s arguments, which Darwin was unable to completely deny, and argued that evolution occurs solely through the process of natural selection. This theory evolved into Mendelian inheritance, which is now considered the most comprehensive theory of evolution. The main content of this theory is that it complements the logic of Darwinian genetics with the fact that traits are transmitted from one generation to the next by genes.
Another major evolutionary theory worth noting is that of Richard Dawkins (1941-). Since the publication of his book The Selfish Gene, Dawkins’ evolutionary theory has become largely accepted as textbook orthodoxy among academics and the general public. The main thrust of his theory is that genes are more than just a tool for individuals to pass on information to their descendants; rather, genes are the agents of the process of evolution, and individuals are merely vessels for carrying them. While Darwin’s theory of evolution holds that natural selection is the driving force behind evolution, the most important difference is that in Darwin’s theory, it was the individual that evolved, whereas in Dawkins’ theory, it is the gene. The idea of genes as agents allows for a smoother explanation of previously unexplained problems. One of the most important examples is insects acting in groups. From the perspective of Darwinian evolution, a worker bee or worker ant working for a queen without the ability to reproduce doesn’t make sense when considered on an individual level. However, since they all share the queen’s genes, Dawkins’ theory can be applied to explain the behavior of ants and worker bees because they are working to reproduce those genes. Dawkins’ theory has been accepted as orthodoxy in many areas of evolutionary theory, as it can explain the behavior of ants and bees because they all share the queen’s genes, and they are working to reproduce those genes.
However, there are many reasons why evolutionary theory, while widely accepted as a theory, is still only a hypothesis, including many controversies involving creationists. For creationists and many religious people, evolutionary theory is controversial because it denies something very sensitive, and some scientists argue that evolutionary theory doesn’t currently fully explain great evolution. However, current evolutionary theory generally does not draw a distinction between microevolution and macroevolution, but rather explains that we can see the phenomenon of macroevolution, which involves countless microevolutions and the speciation of species over a very long period of time. There are several other controversies that have led some to reject the theory of evolution.
Evolution is a theory that explains the diversity of species on Earth and how we have changed over time. At its core, it means that species evolve based on four principles: self-replication, mutation, environmental limitation, and finally, natural selection. Although the theory is often opposed to creationism and is constantly questioned, the fact that it successfully explains so much of the natural world and is constantly evolving to explain even more is a testament to its value.