An Argumentative Essay on Evolution: Finding the Right Proof

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Evolution of a Writer

Very often in high school or in college you would get an assignment to write an argumentative essay. Evolution is often one of those assigned topics in humanities classes.

Regardless of your personal religious beliefs, evolution is an accepted notion in science. It is called the unifying field of biology, and schools teach it as a foundational tenant. Only biological evolution through the process of natural selection explains all the centuries of accumulated evidence on the changing of life through the eons. That is not to say it invalidates any personal beliefs, but rather scientifically, it is the only game in town.

Here I would like to give you a hand by summarizing the facts that validate the theory of evolution and showing how to structure your arguments and to write about an argumentative topic from the basis of supporting evolutionary theory. Like any argumentative essay it is critical that you understand your subject matter.

What Is Evolution?

First of all, it is a scientific theory. That means it is a body of repeatedly tested and substantiated collection of observations, evidence and hypothesis that explain an aspect of the natural world. There are many theories, like the theory of gravity, atomic theory, and molecular orbital theory that are in the same realm as evolution.

So what is evolution itself? Evolution is the process of gradual change of biological species over time. This can be expressed a function of genetic drift, mutations, gene migration and other biological processes.

By exploring the definition of the word theory, it is important to stress the idea that a theory in science is not the same as its quotidian meaning. A colloquial theory is a conjecture; a hunch. Evolution is neither. It is a body of knowledge. It is important when structuring your arguments to make this distinction early and often. By featuring this misconception, you would from the very beginning add validity to your essay.

Evolution as a theory includes many concepts such as natural selection, gradualism, speciation and common ancestry. This is not an exhaustive list, but in this article I will focus on them as the most fundamental.

Natural Selection as an Evolutionary Mechanism

Before we understand natural selection, we must first understand genetic mutations. Mutations are changes to a genetic code, either to that of an individual or a population. These changes are most often neutral, but some are harmful and others are beneficial. A beneficial mutation will allow an individual to have more offspring and spread the gene through the population over time. If natural selection is the engine of evolution, mutations are the gasoline that powers it.

Here you can refer to a very well-known example of a peppered moth evolution. Before the Industrial Revolution the peppered moths in England were white with only few black speckles. Black peppered moths were rare as they could not camouflage as well. As the Industrial Revolution spread, soot filled the streets and air. The black color trait was selected by for by natural selection since the moths were more camouflaged. This is a textbook example of natural selection where certain members of a species were positively selected and were more likely to pass on their genome.

The color of their bodies was their phenotype. It is something that people can observe with bare eyes. A change in surroundings often demands a change in phenotype, thus resulting in genetic alterations and genotype transformation. It is predicated on the idea that better adapted organisms are more likely to live on and produce offspring.


As you might have guessed from the title speciation is a formation of news species. There are two major types of speciation:

1) allopatric - when identical species are separated geographically and, as a result, develop distinct features and branch into separate groups

2) sympatric - when identical species are not separated geographically, but still develop different traits due to behavioral or climate changes.

Charles Darwin first discovered speciation by studying finches on the Galapagos Islands that were vastly different. You can use this example as an argument for your essay to prove that species were not created all separately, but actually evolved based on the evolutionary pressures.

Finches when split up had to advance heterogeneous attributes that were motivated by their environment and the available food. Therefore, they had different beaks hinging upon what they ate.

Of course, these changes are gradual, and fossils show many intermediate stages before a complete adaptation. This example can be used to bolster your arguments in your paper. Fossils demonstrate that they improved their best qualities.

Common Ancestry

This is one of the most understandable points to advocate. The idea is that all species have a common ancestor that allows tracking all the metamorphoses that occurred throughout history.

Life emerged 3.5 billion years ago with single simple cells that replicated themselves and triggered the development of all modern species. It seems like an impossible argument to affirm taking into account the diversity of life one can observe today. However, you can again turn to fossils for help.

The objection for your argumentative essay here is all the observable facts that deny the possibility of a common ancestry. What is common between a reptile and a mammal? How can you prove their shared lineage?

Fossils, however, show that species evolved and branched consistently and invariably. For instance, whales once had legs, which their fossils and modern skeletons show. Moreover, many animals, including whales as well have rudimentary body parts that indicate their far-away past.

Delving deeper into these links are solid arguments to include in a paper about evolution.

DNA Similarities

One of the most potent arguments for evolution is, of course, DNA. This is not something that is subjective based on individual observations. This is one of the most comprehensive tool of evolution research so far.

The striking fact is that all species, even the prokaryotes have DNA. The degree of its similarity varies depending on how long ago species deviated from the common ancestor. By comparing DNA we can construct a family tree of all living organisms and prove their connection.

We all use the same molecules as instructions, and it is the same instructions that force us become increasingly different. We all have DNA and RNA that are responsible for the formation of a living being.

DNA is a link that connects life on Earth. It is powerful evidence that you can expound on to bolster your argument.

All Things Considered…

It is easy to argue for evolution. There is so much scientific evidence available that prove your point. Moreover, it is a commonly established view on the development of life.

Nevertheless, it is also hard. You do not want to come off as intolerant, or conceited, or all-knowing. You do not want to offend people’s religious beliefs. There is always a fine line between being convincing and offensive.

You could end your argumentative essay on a moral note to make your essay more compassionate. Evolution has shown us that we all are distant relatives. Therefore, it is crucial to treat other living beings as brothers and sisters. This is also what most world religions teach.

It is hard to break people’s misconceptions with forceful arguments. You might want to carefully slide your way through, connecting evolution with something bigger than science. Ending your argumentative essay with such a grandiose and, at the same time, simple notion can go a long way by making people accept your ideas more easily.

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