In this blog post, we will look at how the theory of evolution explains the origin and evolution of various species through natural selection and genetic variation.
The theory of evolution is a theory that explains how all living organisms have changed as a result of evolution and how new species have formed through the factors or structures that affect evolution. The theory of evolution is just a theory that explains reality, like the theories of other scientific fields, so it cannot be argued to be correct or incorrect. However, it is no exaggeration to say that it is the most discussed theory because it offers an alternative to the creation theory that many people believe in. Therefore, while scientists who support the theory of evolution have discovered new information to prove the theory of evolution, those who oppose it have pointed out the flaws in the theory.
The Big Bang is a theory that explains the beginning of the universe in physics. It is based on Edwin Hubble’s observation that the universe is expanding, and the theory of evolution also explains the evolutionary structure of living things, just as the Big Bang theory explains the beginning of the universe. Evolution is manifested through the processes of replication, mutation, competition, natural selection, and gene drift, of which the concept of natural selection was first proposed by Charles Darwin. This concept is the closest theory to reality, and many people have accepted the theory of evolution under the influence of Darwin. However, the controversy over the theory of evolution began after the publication of Darwin’s book “On the Origin of Species.” Even today, people’s reactions are mixed, which is because people learn about evolution here and there and do not have objective information.
Some people misunderstand that humans evolved from chimpanzees, but this is a false understanding. Evolutionists do not claim that humans evolved from chimpanzees. They believe that chimpanzees and humans are different species but have the same ancestor. Then, you may be wondering how a single animal could turn into completely new species. A species is a group of animals that can produce fertile offspring by mating with each other, and the offspring produced in this way can also mate with each other.
All living things are unique, which is an essential element in evolution. Individuals of the same species may look similar, but each has slightly different characteristics. These differences are caused by genetics. All living things are made up of cells, and cells contain DNA, which contains information about living things. This information provides instructions for what cells should do and how they should do it, and determines the characteristics of each living organism. And every living organism has a unique DNA. Genes differ slightly from one individual to another, and this is why individuals have different characteristics.
Nature favors as many subtle differences as possible. The main cause of the uniqueness of each individual occurs during the process of heredity. Living organisms pass on their characteristics to their offspring in the form of DNA, and recombination and mutation alter the DNA, causing each offspring to look different from the others. Random recombination and mutation create individuals with random characteristics, and these individuals mix and continue to be passed on. This is the reason for the diversity of living organisms.
This is where the key concept of Charles Darwin’s theory of evolution, natural selection, comes in. While each individual has different characteristics, nature selects the individuals with stronger and more advantageous characteristics for survival, and the weaker individuals eventually disappear. Individuals with advantageous characteristics survive and can pass on their enhanced characteristics to their offspring. Eventually, evolution occurs in the direction of enhanced characteristics.
When explaining the theory of evolution, the example of the finches living on a remote island is a good example. A few hundred years ago, a small number of finches moved to the Galapagos for some reason. This island was a completely different environment for the finches. Without any natural predators, it was a very comfortable environment, and they quickly multiplied and filled the island. As a result, there was less and less food on the island. Now, the friends became competitors. This is when natural selection intervened. The finches became differentiated and individualistic through their slightly different beaks, which allowed them to avoid competition with other members of their species. Some finches’ beaks became adapted to digging up insects from the ground, while others’ beaks became adapted to cracking the shells of seeds. As a result, the finches were able to separate their ecological niches and avoid competition. They began to mate preferentially with birds that used the same habitat, and over several generations, these traits became stronger. Now the differences between the insectivorous birds and the seed-eating birds have become so great that they cannot interbreed. This means that different species have emerged. Today, there are 14 species of finches in the Galapagos. Each of these finch species shows that they have descended from a common ancestor.
When we consider the various species that have evolved from a common ancestor, it is easy to understand that chimpanzees and humans are different species but have the same ancestor. Evolution does not proceed in a chain, but has a branching structure like a tree. All living organisms are located at the very end of the tree, and have a common ancestor at the roots of the tree.
Another misconception about evolution is the claim that there must be an intermediate creature. This stems from the misconception that there must be an intermediate form of life in the process of evolution from a single animal to a completely new species. For example, consider two species, A and C. Assuming that A is the ancestor of C, people think that they should find the species B in between. However, even if they find the fossils of species B, people will insist that they should find an intermediate form between B and C. This is an infinite loop. The fact that the fossil record is incomplete also contributes to this misconception. In fact, it is a common lesson in geology that only one in a million organisms becomes a fossil. It is also more appropriate to understand the fossils that have been found as “key positions” in the evolutionary process rather than “intermediate organisms.”
Although various opinions on evolution have existed since before the Common Era, Darwin’s theory of evolution is the most widely known. However, the theory of evolution is not limited to Darwin’s theory. Many scientists have made various claims since Darwin. The theory of punctuated equilibrium argues that evolution does not occur over time, but rather occurs rapidly due to sudden natural disasters. The selfish gene theory views evolution as something that should be understood from the perspective of genes rather than individuals. Modern evolutionary theory considers other evolutionary mechanisms in addition to Darwin’s natural selection and is based on genes and populations.
Evolution is not a result but a process. Darwin’s theory of evolution is a representative example, which has been further refined by the discovery of genes. However, it has been controversial as it conflicts with religion in explaining the origin of humans. Darwin’s theory of evolution is similar to the Big Bang theory in that it explains the process of evolution as a single theory. Since the accuracy of the theory of evolution cannot be proven, it will continue to be debated.
