Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store

Difference Between Darwinism and Neo Darwinism

ffImage
Last updated date: 17th May 2024
Total views: 363k
Views today: 4.63k
hightlight icon
highlight icon
highlight icon
share icon
copy icon

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 basis 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 accumulate 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. Below are some differences between Darwinism and Neo Darwinism.

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.

 

Conclusion

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.

FAQs on Difference Between Darwinism and Neo Darwinism

1. What is Neo Darwinism?

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?

Neo Darwinism arose from the concept of Darwinism (that is used to describe the theory of evolution that was proposed by Charles Darwin). However, there are some significant differences between the two theories. These dissimilarities are as mentioned below:

  • The first and foremost difference between the two theories is the absence of genetic evidence for the theory of Darwinism. During the time in which Darwinism was proposed, most of the evidence was based on the examples of organisms through visual inspection. Since the field of genetics was still in its infancy, not much genetic data could be procured in support of Darwinism. On the other hand, Neo Darwinism largely incorporates genetic evidence and is strongly in compliance with the genetic findings of the later stages.

  • Sometimes Neo Darwinism is referred to as Darwinism without Lamarckism. This is because, unlike the theory of Darwinism, Neo Darwinism does not take into account the inheritance of acquired characteristics and discards the use-disuse theory inherent in Lamarckism (it states that the development or degeneration of organs is based on the use or disuse of organs by an individual of a species).

  • According to the theory of Neo Darwinism, there has been a special reference to the phenomenon of reproductive isolation (for a very long period in the geological timeline), which has been found to create divergence or branching out of a species in the evolutionary tree. Darwinism has no specific mention of reproductive isolation in organisms.

3. Is Darwinism the same as Natural Selection?

Natural selection is the process by which certain inheritable traits and features in an organism of a population are preferred (“selected”) by natural forces over other traits found in the population, which overall enhances the survival and reproductive abilities of that individual. Natural selection gives a competitive advantage to one individual over other individuals of the same species. So, yes, the phenomenon of natural selection is the core of the evolutionary theory of Darwinism. Darwin in his theory proposed the process of natural selection as the defining factor of variable inheritance of characteristics and explained the mechanism of evolution through natural selection.

4. What are the differences between modern synthetic theory and Orthogenesis?

The major differences between the Modern Synthetic theory and Orthogenetic theory of evolution are as follows:

  • Orthogenetic evolution, or progressive evolution as it is sometimes known, was first put forth by in 1893 Wilhelm Haacke and later popularised by Theodor Eimer; it was championed by prominent scientists of that time (such as Jean-Baptiste Lamarck, Pierre Teilhard de Chardin, and Henri Bergson). Orthogenesis proposed the idea that evolution is an obsolete biological process and an internal driving force in the organisms drives the process to achieve more biological complex forms with a specific goal (teleology) during their course of evolution. 

  • The modern synthetic theory was first explained by Julian Huxley in his book “Evolution: The Modern Synthesis”. It is by far the most accepted theory to explain the process of evolution. It combines elements of natural selection, reproductive isolation and genetic variations to explain the evolution of various species in nature. Unlike orthogenesis, modern synthesis does not discard the process of natural selection. Modern synthesis does not imply that organisms evolve to attain a specific predefined goal. Rather, evolution is thought to be a natural consequence of the various underlying mechanisms and forces operating on a species at a given point in time.

5. What does the theory of Lamarckism imply? How is it different from the theory of Darwinism?

The major difference between Lamarckism and Darwinism is that Lamarckism states the inheritance of acquired traits from the parental to the progeny generation. It explains the origin of new traits in a species as simply a consequence of the use and disuse of various biological attributes (e.g. organs that are used more tend to be more developed in offspring). Darwinism, on the other hand, describes an evolution in species by means of natural selection. It does not accept the view that excessive use or disuse of biological attributes will directly impact its development or deterioration in the offspring. Also according to Darwinism, acquired traits can not be inherited by the progeny generation. Thus, the theory of Lamarckism was rejected in favour of Darwinism.