Evolution is a fascinating topic that has been debated for centuries. It is the process by which different species of organisms have developed and diversified over time.

This process has been studied by scientists, naturalists, and philosophers alike. But what theory can evolution be explained by? Let’s dive into some of the most famous theories.

The Theory of Natural Selection

The theory of natural selection was first proposed by Charles Darwin in the mid-19th century. According to this theory, organisms that are better adapted to their environment are more likely to survive and reproduce than those that are not well adapted. Over time, this leads to the development of new species as traits that are advantageous become more common in a population.

This theory is supported by a vast amount of evidence from various fields such as genetics, paleontology, and ecology. It explains how organisms can adapt to their surroundings and why certain traits may become more common in a population over time.

The Theory of Genetic Drift

Another theory that explains evolution is the theory of genetic drift. This theory proposes that changes in the gene pool of a population occur due to random events such as mutations or chance events like natural disasters or migration.

Genetic drift can lead to the development of new species as certain traits become more common in a population due to chance rather than adaptation. However, genetic drift is considered less significant than natural selection when it comes to explaining evolution.

The Theory of Lamarckism

The theory of Lamarckism was proposed by Jean-Baptiste Lamarck in the early 19th century. This theory suggests that organisms can pass on acquired characteristics to their offspring.

For example, if an organism develops stronger muscles during its lifetime through exercise, its offspring will also inherit these stronger muscles. However, this theory has been largely discredited as studies have shown that acquired characteristics cannot be passed on through genes.

The Theory of Punctuated Equilibrium

The theory of punctuated equilibrium was proposed by Stephen Jay Gould and Niles Eldredge in the 1970s. This theory suggests that evolution occurs in spurts rather than gradually over time.

According to this theory, new species may develop quickly during periods of rapid environmental change or when a small population becomes isolated from the larger population. This theory is supported by evidence from the fossil record, which shows sudden bursts of new species followed by long periods of stability.


In conclusion, there are several theories that can explain evolution. The most widely accepted and supported theory is the theory of natural selection, which proposes that organisms that are better adapted to their environment are more likely to survive and reproduce.

Other theories such as genetic drift, Lamarckism, and punctuated equilibrium have also contributed to our understanding of evolution but are considered less significant. Regardless of the theory you believe in, it is clear that evolution has played a significant role in shaping the diversity of life on our planet.