Difference Between Darwinism and Neo-Darwinism

We know that every organism on earth has evolved for thousands of years. But how do you define this evolution? What is the basis of evolution? What are the main factors that affect the evolution of organisms? Theories like Darwinism answered these questions. With the advancement of science, more theories have been developed that contrast with Darwin’s theory of evolution.

What is Darwinism?
What is Neo-Darwinism?
Difference between Darwinism and Neo-Darwinism
Practice problems
FAQs

What is Darwinism?

Darwinism refers to the evolutionary theory that Charles Darwin put forth in his pioneering book, "On the Origin of Species," released in 1859. It implies that species evolve throughout time due to heritable variations in populations affected by natural selection.

According to Darwinism, those that possess favourable characteristics are more likely to live longer and produce offspring, transmitting those traits onto their progeny. Over generations, species adapt and diversify due to the slow development of beneficial characteristics.

Darwinism also includes the idea of a "survival of the fittest," in which individuals compete for scarce resources, and those with favourable characteristics have a better chance of surviving.

The major principles that drive Darwinism are:

Variation and Inheritance: Darwinism understands that variation exists among individuals inside a population. These changes may be heritable and transferable from one generation to the next via the process of inheritance.
Survival of the fittest: Darwinism emphasises the idea of the "survival of the fittest," in which individuals with favourable characteristics have a higher likelihood of surviving and reproducing, whereas individuals with fewer favourable characteristics could find it difficult to compete successfully.
Natural Selection: The main force behind evolutionary development is natural selection. The likelihood of survival, reproduction, and passing on favourable characteristics to the generations is higher in people with traits that help them better adapt to their environment.
Speciation and Gradualism: It asserts that new species evolve due to a process known as speciation, in which different populations develop significant genetic and phenotypic differences to prevent interbreeding, resulting in the formation of distinct species.

What is Neo-Darwinism?

Neo-Darwinism, commonly called modern synthesis, was developed in the early 20th century by integrating genetics and Darwinian theories. It advanced Darwin's theory by incorporating genetic principles into the study of processes associated with evolution.

Neo-Darwinism states that the source of evolutionary change is genetic variety, principally originating from mutations and genetic recombination during the reproduction process. Although it emphasises natural selection as the primary mechanism underlying evolution and species diversification, it also considers other factors, including genetic drift and gene flow.

Neo-Darwinism offers a thorough account of the genetic foundation of variation and the processes by which favourable traits spread over time among populations.

The major principles that define Neo-Darwinism are as follows:

Genetic Variation: Neo-Darwinism acknowledges that population-level genetic variation is the starting point for evolutionary shifts. Individuals' phenotypic variances result from these variations.
Mendelian Inheritance: It recognises that during reproduction, discrete units known as genes that segregate and recombine transmit genetic information from parents to children. This procedure maintains the continuity and diversity of genetic features among populations.
Natural Selection: Neo-Darwinism highlights natural selection as an essential driving force of evolutionary shifts. Organisms with qualities that give them a reproductive or survival advantage are more inclined to transmit their genes to subsequent generations.
Genetic Drift and Gene Flow: Genetic drift is the term for unplanned changes in the frequency of genetic variations within a population. When people move across populations, there is a phenomenon known as gene flow that introduces new genetic material and modifies the genetic structure of both populations.

Difference Between Darwinism and Neo-Darwinism

The major difference between Darwinism and Neo-Darwinism are as follows:

Darwinism	Neo-Darwinism
The theory of the evolution of species by Charles Darwin is based on natural selection.	The modern version of Darwin’s theory of evolution integrates genetic studies.
It is the original theory of evolution.	It is an advanced theory based on Mendelian genetics and natural selection.
The accumulation of phenotypic variation is the major driving force of this theory.	The accumulation of genetic variation is the major driving force of this theory.
It doesn't have the answer to the variations.	It describes the reasons for variation, which include mutation, genetic recombination and reproductive isolation.
According to Darwinism, natural selection is the survival of the fittest and the elimination of unfit organisms over time.	According to Neo-Darwinism, natural selection is the differential increase of the fittest genes and genotypes.
It does not agree on isolation is an important factor in evolution.	It states that isolation is a major element of evolution.

Practice Problems

Q1. The theory of natural selection is based on?

A. Changes in the genetic makeup resulting in heritable variations
B. Role of Environment in Evolution
C. Natural selection working on favourable variations
D. None of the above

Ans. C. natural selection theory of evolution works on the selection and growth of organisms with favourable variations.

Q2. The finches of the Galapagos islands provide evidence in favour of?

A. Evolution caused by a mutation
B. Retrogressive evolution
C. Special creation
D. Biogeographical evolution

Ans. D. The finches of the Galapagos islands have common ancestors, but as their feeding habits changed and the geographical conditions changed, their beaks and other structures evolved.

Q3. According to Neo-Darwinsim, _______ is the unit of evolution.

A. Cell
B. Population
C. Species
D. organism

Ans. B. According to Neo-Darwinism, the unit of evolution is a population with its own gene pool.

FAQs

Q1. What is Lamarckism theory?
Ans. Lamarckism is an evolutionary theory based on the idea that physical changes in organisms throughout the course of their lifetimes, such as enhanced growth of an organ or some part due to greater use, may be transmitted onto their progeny.

Q2. Who is the father of evolution?
Ans. Charles Darwin is the father of evolution.

Q3. What are the four pillars of evolution?
Ans. The four principles in action in evolution are inheritance, variation, time and selection. These are the main pillars which are considered the elements of the evolutionary mechanism of natural selection.