Difference Between Darwinism and Neo Darwinism

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Darwinism and Neo Darwinism

The theory of natural selection is the most important aspect of the theory of evolution. The reasoning of the theory of natural selection provides the basis of the evolution of different organisms over millions of years on earth. It also forms the essence of Darwinism. Darwinism in its raw form can be said to be a theory of natural selection of organisms based on the concept of survival of the fittest in a given environment. But this natural selection is widely on the bases of inheritable characteristics that are adaptive and more favourable to the surrounding habitat. You can call it the phenotypic traits of a living organism. Thus, Darwinism focuses on the accumulation of these phenotypic traits while explaining the various species generated through evolution.

One of the missing pieces of Darwinism is that it does not hold into account the genetic changes or mutations and genetic diversity of a species. This aspect is covered in a modern-day derivative theory of Darwinism known as Neo Darwinism. If you are to describe - what is Neo Darwinism theory? Then you can say briefly that Neo Darwinism considers the genetic variation and the influence of genes based on modern-day research as more central to the cause of speciation i.e. formation of new species with respect to the theory of natural selection. Thus, Darwinism and Neo Darwinism are important landmark theories in an attempt to explain evolution, but they both carry significant similarities and differences.

Darwinism and Neo Darwinism Theory

Given below is an appropriate definition of Darwinism and Neo Darwinism:

  • Darwinism: 

Darwinism describes that favourable phenotypic variations which can be inherited are the major cause of speciation. These favourable phenotypic variations get accumulated over certain amounts of time.

  • Neo Darwinism: 

Neo Darwinism describes that the only inheritable genetic variations such as mutations are the major cause of speciation. These genetic variations can be sudden and bring about large changes in a population.

After having known about the definitions of Darwinism and Neo Darwinism, it will be clear to you that both theories have fundamental similarities and differences. Let us have a look at it. 

Similarities Between Darwinism and Neo Darwinism Theory

Darwinism and Neo Darwinism theory depict the cause of the theory of natural selection and a legitimate step in understanding evolution itself. Following are the similarities between the theories:

  • The Why of the Concepts: 

Both the theories are an important step towards explaining speciation and the driving forces behind it.

  • The Result of the Explanation: 

Both the theories explain the process of evolution amongst the organisms.

  • Mode of the Explanation: 

Both the theories are heavily dependent upon the cause of speciation as variation be it phenotypic or genotypic but ultimately a variation in the biological characteristics of the organism of a species.

  • Characteristics of the Variation: 

Variation is explained as a cause of speciation in both the theories. An important characteristic of this variation is that it is inheritable by the succeeding generations. This important detail is common to both - Darwinism and Neo Darwinism theory.

Differences Between Darwinism and Neo Darwinism Theory

Even though both theories have similarities underlying the basis of an explanation of speciation, there are fundamental differences between them. They have different approaches because of the development of scientific theories at different times. Given below are some difference between Darwinism and Neo Darwinism.


Neo Darwinism

Darwin explained and enhanced the theory of natural selection which came to be known as Darwinism. This explanation was mostly based upon observable facts by the naked eye.

Neo Darwinism is a form of Darwinism which developed after many exemplary findings of genetic research. It explained the theory of natural selection by incorporating genetic findings. 

This is an original theory built on the extensive research of observable species of birds, butterflies and other living organisms carried by Darwin himself

This theory is adapted from the theory of natural selection by Darwin, where it replaces the premier importance of observable characteristics to genetic characteristics. 

The major cause of changes in species is described by the accumulation of the inheritable phenotypic changes over generations of an organism. 

The major cause of variation in species according to Neo Darwinism is the variation that takes place in the genes of particular organism i.e. mutations which can be inherited as per the laws given by Mendel

The cause behind the phenotypic variation has not been explained by Darwinism

Neo Darwinism theory explains the cause of variation of the genes as mutations in the genes, genetic recombination, natural selection and reproductive isolation.

The phenotypic variation as discussed in above points happens to occur in the pool or a group of individuals. 

The genetic variations given above occur in the genetic pool.

The natural selection according to this theory happens for the most adaptive individual or commonly called survival of the fittest as only they will be able to reproduce more than the required amount for survival.

In this case, the natural selection happens of the fittest gene or genotype.

There is no place for reproductive isolation of phenotypic characteristics in this theory of evolution.

Reproductive isolation forms a significant part of the theory of evolution according to Neo Darwinism.


Even though there are considerable significant differences, you should not consider one theory to be above the other. Both theories have an important role in explaining evolution and why and how new species arise. Both the theories provide valid arguments and are an important part of evolutionary research. Scientists assert the use of both the theories - Darwinism and Neo Darwinism Theory for understanding and explaining evolution.

FAQ (Frequently Asked Questions)

1. What is Neo Darwinism?

Ans: Neo Darwinism is the theory of natural selection taking into consideration the genetic factors that give rise to new species. As a modified modern form of Darwinism, it explains that new species are formed because of mutation in genes, recombination of fittest genes and reproductive isolation of the strong genes. Thus, in this theory, genetic variation takes the centre stage for speciation.

2. What is the Difference Between Darwinism and Neo Darwinism?

Ans: The significant difference between Darwinism and Neo Darwinism is that while Darwinism describes the accumulation of phenotypic variations over generations as the cause of speciation, Neo Darwinism describes genetic variation as the cause of speciation which can cause widespread changes in a single generation.

3. Is Darwinism the Same as Natural Selection?

Ans: Natural selection is the theory of evolution describing the reason for the creation of new species. Darwinism on the other hand refers to a group of theories which include the theory of natural selection, the Weismann barrier and the central dogma of molecular biology.