Evolution is the scientific theory that explains the diversity of life on earth. It states that all living organisms are related to each other through a common ancestor and have changed over time through natural selection.

However, despite being widely accepted, some scientists argue that there are missing pieces in the theory of evolution. Let’s take a closer look at what is missing.

The Role of Epigenetics

One of the main criticisms of the theory of evolution is that it does not fully account for epigenetics. Epigenetics refers to changes in gene expression that occur without altering the underlying DNA sequence. These changes can be caused by environmental factors such as diet, stress, and exposure to toxins.

While epigenetic changes can be passed down from one generation to another, they are not necessarily permanent. This means that they can potentially be reversed or altered over time, leading to new adaptations and traits.

However, the current theory of evolution does not fully explain how epigenetic changes contribute to evolutionary processes. Some scientists argue that incorporating epigenetics into evolutionary theory could provide a more complete understanding of how organisms adapt and evolve.

The Origin of Life

Another area where the theory of evolution falls short is in explaining the origin of life itself. While evolution explains how life has changed over time, it does not explain how life originated in the first place.

There are several theories about how life may have originated on earth, such as the idea that it arose spontaneously from non-living matter or was brought here by meteorites from other planets. However, none of these theories have been conclusively proven, leaving a gap in our understanding of how life began.

The Limits of Natural Selection

Natural selection is often cited as the driving force behind evolutionary change. It operates on the principle that individuals with advantageous traits are more likely to survive and reproduce than those without them, leading to the spread of these traits in a population over time.

However, natural selection has its limitations. For example, it cannot account for traits that do not confer an immediate survival advantage but may be beneficial in the long run. It also cannot explain the existence of complex structures that require multiple mutations to arise.

Some scientists argue that other mechanisms, such as genetic drift and horizontal gene transfer, may play a larger role in evolutionary change than previously thought. Incorporating these mechanisms into evolutionary theory could provide a more accurate picture of how organisms evolve.


While the theory of evolution has been incredibly successful in explaining the diversity of life on earth, there are still gaps in our understanding. Incorporating new ideas and theories such as epigenetics, the origin of life, and alternative mechanisms for evolutionary change could help fill these gaps and provide a more complete picture of how life evolves over time.