An Investigation of The Features of Theory of Evolution

Introduction to Evolution

Evolution is the theory that organisms have developed with their bodies modified over time. New species have evolved looking extremely different from their predecessors. It’s because of science, we understand the beauty of evolution and we see it with evidence that supports this theory in fossil records. This is purely scientific. The scientific method was required to fully understand and appreciate the process of evolution. The method involved questioning, experimenting, and testing a hypothesis, which is an idea that has not yet been proven but requires the scientific method to see if it is true or not. With regards to earth science, there are questions that need to be answered and scientific methods aid in answering these questions with discoveries aiding the process. If a hypothesis (the starting point for an investigation from a proposed explanation based on restricted evidence) is tested, a theory begins to develop. A scientific theory is one which is factual, and observations are made in the real world, and has to be falsifiable. However, a theory is just an idea that has not been observed and is just a ‘hunch’ on something. The theory of evolution has been questioned numerous times on the truth of it, which makes it a scientific problem. However, it is a work in progress, and since it happened in the past, there was no one who observed it. With an abundance of evidence in the fossil record and multiple theories, the law of parsimony is very helpful in that its principle is to select a solution with the fewest of assumptions, which makes it more accurate and easier to understand.

Scientific Communication and Evolution

Scientists are able to communicate their results and discuss various theories by publishing them in peer-reviewed journals that can be easily accessed by other scientists for approval and confirmation, as well as presenting their results at conferences. This process of peer review ensures that scientific findings are rigorously tested and validated, leading to a more robust understanding of evolutionary processes (Smith, 2020). Other scientists can therefore listen or attend these conferences. With communication, it allows for theories to be more accurate and testable. Such a theory, which states that we humans descended from a common ancestor and with evidence in the fossil record of the horse, is convincing to believe that this is indeed true.

Descent from a Common Ancestor

Descent from a common ancestor, also known as descent with modification, is a fundamental concept of evolution. We all have a common ancestor, which can obviously be traced back using molecular genetic methods. There is so much evidence that supports that we derived from a common ancestor. The evolution of horses is extraordinary as it clearly demonstrates the horses’ lineage transitions. The study of horses was mostly done in North America because there, horses were prevalent. Teeth are very important here since they are preserved well throughout the fossil records and demonstrate the evolution of horses about 55 million years ago. The rate of this evolution has been slow and rapid at times; nothing that is generally consistent. The horses were diminutive compared to modern horses. Eohippus, the first primitive horse in the fossil record, was very small, had two premolars and two molars with an arched back. It also had padded feet, totally different from equines today. It also had four hooves on the forefeet and three hooves on the hind feet. Due to the cranium’s features, it indicates that the brain was much smaller than that of horses today. The horses in earlier times would have had a browser’s diet because of their teeth (short-crowned teeth). In the Eocene period, there was the evolutionary change to the orohippus, which technically had the same body structure, but the premolars and molars were on both sides of the jaw. It then traversed to the epihippus, which had continuous crests. The mesohippus (after the epihippus), resembled modern horses with longer and slender legs. A vestige was present in the mesohippus (there were three toes on both the fore and hind feet). Miohippus was the next evolutionary horse that had been divided into two groups. Ancitheres, one of the groups that split from the miohippus, comprised three-toed browsing horses. However, not as important as parahippus (which emerged in the early Miocene), which is the key that led to modern horses. This is so because their teeth were different from their predecessors. It has stronger crests with a very long crown. This was suited for a side-to-side motion to chew grass, however not completely getting rid of browsing. Teeth like these developed because grass was becoming widespread in North America and therefore needed to adapt to the environment. The complete transition from having a browser’s diet to a grazer one occurred in merychippus. There was a fusion of the bones in the lower leg which meant that they were becoming swift runners. They gained strong ligaments and developed a body structure as we see in modern horses for a mechanism to spring up. Merychippus enabled other lines of horses to evolve and, most importantly, the emergence of the pliohippus. After the pliohippus came equus. Zebras, donkeys, and other forms of modern equines evolved from pliohippus. In this time, the form of spring mechanisms developed even more and longer cheek teeth for eating. These horses then populated different places in later times. Przewalski’s horse, along with the tarpan and Ukrainian Steppes, are known to be the predecessors of domestic horses. Horses have such an important role in understanding evolution by studying their development and modification throughout earth’s history. By doing this, it hints at some truth of having a common ancestor. It is key in learning that due to environmental changes, they had to adapt to it in order to survive by modifying some parts of their body genetically (natural selection).

Natural Selection and Adaptation

Natural selection was brought about by the drastic changes in the environment in which organisms have variation and reproduce differently in genotype. Migration (change in the gene frequency when organisms move from a population), mutation, and genetic drift are all a part of evolution. A perfect example of natural selection is the peppered moth. There was a genetic mutation that allowed for dark wings to occur in the peppered moths. This enabled the moths to better camouflage on the darkened tree trunks (polluted tree trunks) to survive from predatory birds. There are beneficial mutations with natural selection which help the organism to survive better. Due to environmental changes and natural selection, some functions of the organs weren’t required any longer. These features are known as vestigial structures (Darwin, 1859).

Vestigial Structures and Atavisms

Vestigial structures are features that don’t have a function in a species; however, they had a purpose in the organism; one of an important function once in the past. They develop into atavisms (lost traits) of a species in the past. Atavisms are genes that are passed to offspring which were silenced in the past. With various adaptations, certain organs and limbs are not required or they would have been modified to better suit the environment. They are rendered useless; however, the trait has been passed down to offspring. A typical example would be the coccyx in humans. It’s a tailbone, it doesn’t have any function in us humans. However, it might have been useful for our predecessors (apes) who needed it to aid them in climbing trees. Vestigial organs signify variations in themes of structure present in common ancestors. They provide a great insight into understanding evolution and how our bodies are affected drastically by an environmental change in order to survive. Another important point to note which aids in understanding evolution is the chromosome fusion in humans. In primates, there are 24 pairs of chromosomes. Two separate chromosomes in primates were fused head to head which formed chromosome 2 which have almost identical DNA sequences in humans, hence, the 23 pairs that we have today. It is convincing to believe that evolution is viable and that the earth has existed approximately 4.5 billion years ago and that life changed over time with the evidence provided. The theory is constantly revised and modified to get the best results. Evolution is a part of science which we can’t ignore because we have unanswered questions and sometimes science with numerous experiments, investigations, and research is the solution to answer these questions. We can therefore understand the significance of it in our lives.

References

• Darwin, C. (1859). On the Origin of Species by Means of Natural Selection. John Murray.
• Smith, J. (2020). Evolutionary Communication in Scientific Research. Journal of Evolutionary Studies, 12(4), 45-58.