What Is the Major Concept of the Biological Theory of Evolution?


Jane Flores

The biological theory of evolution is one of the most fundamental concepts in biology and is crucial for understanding the diversity of life on Earth. At its core, the theory of evolution suggests that all organisms on Earth are related and have descended from a common ancestor over the course of millions of years. In this article, we will explore the major concepts behind this theory and how they have been supported by scientific evidence.

The Basics of Evolution

Evolution is a process that occurs over time as populations of organisms change in response to their environment. These changes can be driven by a variety of factors, including natural selection, genetic mutations, and genetic drift. The end result is that populations become better adapted to their environment, which can lead to the development of new species.

Natural Selection

One of the key drivers of evolution is natural selection. This process occurs when certain traits become more or less common in a population based on their ability to help individuals survive and reproduce. For example, if a population of birds lives in an environment where there are many predators, those with stronger wings or better camouflage will be more likely to survive and pass on their genes to future generations.

Genetic Mutations

Another important factor in evolution is genetic mutations. These are changes that occur in an organism’s DNA sequence, and they can happen randomly or as a result of exposure to certain environmental factors such as radiation or chemicals. While most mutations are harmful or neutral, some can provide an advantage in certain environments and become more common over time.

Genetic Drift

Genetic drift refers to random changes in gene frequencies that occur due to chance events such as natural disasters or migrations. Over time, these events can cause certain traits to become more or less common in a population even if they don’t necessarily provide any survival advantage.

Evidence for Evolution

While the concept of evolution has been around for centuries, it wasn’t until the 19th century that scientists began to develop a more rigorous understanding of how it works. Since then, there has been an enormous amount of scientific evidence gathered to support the theory of evolution.

Fossil Records

One of the most compelling pieces of evidence for evolution comes from the fossil record. Fossils are the preserved remains or traces of organisms that lived in the past, and they can provide valuable information about how species have changed over time. By studying fossils from different periods in Earth’s history, scientists have been able to track the evolution of various groups of organisms and identify patterns in their development.

Comparative Anatomy

Another important source of evidence for evolution is comparative anatomy. This involves comparing the physical structures and characteristics of different organisms to look for similarities and differences. For example, all mammals have a similar bone structure in their forelimbs, which suggests that they share a common ancestor.

Genetic Analysis

More recently, genetic analysis has become an increasingly important tool for studying evolution. By comparing DNA sequences from different organisms, scientists can identify similarities and differences that provide clues about their evolutionary history. For example, humans share more than 98% of our DNA with chimpanzees, which suggests that we are closely related.

The Importance of Evolution

The theory of evolution has important implications not just for biology but also for many other areas such as medicine and agriculture. By understanding how species evolve over time, we can better predict how they will respond to changes in their environment or new threats such as diseases or pests.


In medicine, knowledge about evolution is crucial for developing new treatments and vaccines. By understanding how pathogens such as viruses or bacteria evolve over time, scientists can predict which strains are most likely to be resistant to current treatments and develop new ones that are more effective.


In agriculture, evolution is important for developing more sustainable farming practices. By understanding how crops evolve in response to factors such as climate change or pests, farmers can develop strategies for breeding or selecting plants that are better adapted to these challenges.


The biological theory of evolution is a fundamental concept in biology that has been supported by an enormous amount of scientific evidence. By understanding how species evolve over time, we can better understand the diversity of life on Earth and develop strategies for managing our environment and resources more sustainably. Whether you’re interested in biology, medicine, or agriculture, a solid understanding of evolution is essential for success.