Why Do Scientists Say That Evolution Is a Theory Quizlet Astronomy?


Jane Flores

Evolution is a topic that has been widely debated by scientists and non-scientists alike. While the vast majority of scientists support the theory of evolution, there are still those who reject it.

So, why do scientists say that evolution is a theory? Let’s take a closer look.

What is Evolution?

Before we dive into why scientists call evolution a theory, let’s first understand what evolution actually means. At its core, evolution is the process by which different species of living organisms develop and change over time.

What is a Theory?

A theory in science is an explanation for observed phenomena that has been extensively tested and supported by multiple lines of evidence. It is not just an idea or hypothesis but rather a well-supported explanation for how something works.

Why Do Scientists Say That Evolution Is a Theory?

So, why do scientists refer to evolution as a theory? The answer lies in the scientific method.

Scientists approach any question or problem with an open mind and gather evidence through experimentation and observation. When it comes to evolution, there are numerous pieces of evidence that support the idea that all living organisms have evolved from common ancestors over billions of years.

Some of this evidence includes:

  • Fossil records that show gradual changes in species over time
  • DNA sequencing that reveals similarities between different species
  • Observations of natural selection in action

While there may be some disagreement among scientists on specific details about how evolution occurs or what factors contribute to it, the overwhelming majority agree that evolution itself is real and supported by extensive evidence.

The Difference Between Scientific Theories and Non-Scientific Theories

It’s important to note that when scientists refer to something as a theory, they don’t mean it’s just an idea or hypothesis. Scientific theories are backed up by a wealth of evidence that has been repeatedly tested, analyzed, and peer-reviewed by other scientists. This is different from non-scientific theories like conspiracy theories or unproven ideas that lack credible evidence.


In summary, evolution is a theory in the scientific sense of the word. It is a well-supported explanation for how living organisms have developed and changed over time.

Scientists refer to evolution as a theory because it is extensively tested and supported by multiple lines of evidence, not just an idea or hypothesis. It’s important to understand the difference between scientific and non-scientific theories to better evaluate claims made in various fields of study.