Why Are Acquired Traits Not Part of Darwin’s Theory of Evolution?


Martha Robinson

Evolution is a fascinating concept that has been studied by scientists for centuries. Charles Darwin, in particular, is well-known for his theory of evolution.

However, there are certain aspects of evolution that Darwin did not include in his theory. One such aspect is acquired traits. In this article, we will explore why acquired traits are not part of Darwin’s theory of evolution.

The Basics of Darwin’s Theory of Evolution

Before we delve into why acquired traits are not part of Darwin’s theory of evolution, let’s first understand what the theory is. Darwin’s theory of evolution states that all species of organisms have evolved over time from a common ancestor through the process of natural selection. This means that organisms with favorable traits are more likely to survive and pass on those traits to their offspring.

What Are Acquired Traits?

Acquired traits are characteristics or modifications in an organism’s body or behavior that arise as a result of environmental factors or experiences during an organism’s lifetime. These traits are not inherited genetically but rather developed over time due to external factors.

For example, if a person spends a lot of time lifting weights and building muscle mass, their offspring will not necessarily inherit the same level of muscle mass. Similarly, if a giraffe stretches its neck to reach higher leaves on trees, its offspring will not inherit a longer neck.

Why Acquired Traits Are Not Part Of Darwin’s Theory

One reason why acquired traits are not part of Darwin’s theory is that they cannot be passed down from one generation to the next genetically. In other words, these traits do not impact an organism’s DNA and therefore cannot be passed on to future generations.

Darwin focused on natural selection as the driving force behind evolution – the idea that only the fittest organisms survive and pass on their favorable traits to their offspring. According to him, these favorable traits were inherited genetically, and not acquired through external factors.

Furthermore, Darwin did not have access to modern genetics and DNA research during his time. He did not know how traits were inherited or how genetic mutations occurred. Therefore, it is understandable why he did not include acquired traits in his theory of evolution.

The Role Of Epigenetics

Epigenetics is a relatively new field of study that explores how environmental factors can impact gene expression without changing the DNA sequence itself. This means that acquired traits can have an impact on gene expression without altering the genetic code.

While epigenetics may challenge some aspects of Darwin’s theory, it does not necessarily mean that acquired traits are now part of the theory of evolution. Rather, it adds another layer to our understanding of how organisms evolve over time.


In conclusion, acquired traits are not part of Darwin’s theory of evolution because they cannot be passed down genetically from one generation to the next. Darwin’s focus was on natural selection as the driving force behind evolution and how inherited favorable traits lead to the survival and reproduction of organisms. While epigenetics may challenge certain aspects of this theory, it does not change the fact that acquired traits are still not considered a part of Darwin’s original theory.