What is Neo-Darwinism?
2 Answers
Neo-Darwinism is the integration of Darwin's theory of evolution by natural selection, with Mendel's theory of genetics as the basis for biological inheritance and mathematical population genetics.
Explanation:
It is also called as theModern Evolutionary Synthesis.
Essentially neo-Darwinism introduced the connection between two important discoveries, the units of evolution with the mechanism of evolution. According to Modern Synthesis, evolution is gradual and can be explained by small genetic changes in population over time, due to the impact of natural selection on the phenotypic variation among individuals in the populations.
Basic parameters of the Modern Synthesis (though many are not agreed upon universally) are:
1) the primacy of natural selection as the creative agent of evolutionary change.
2) gradualism (accumulation of small genetic changes)
3) the extrapolation of micro evolutionary trends (changes within species) to macro evolutionary trends (changes about the species level, such as origin of new designs and broad patterns in history).
Evolutionary change is a shift of the frequency of genes in a population and macro evolution trends come from gradual accumulation of small genetic changes. A major conclusion of the modern synthesis is that the concept of populations can explain evolutionary changes in a way that is consistent with the observation of naturalists and the known genetic mechanism.
Neo Darwinism is a blend of De Vrie's mutation theory and Darwin's theory of descent with modification.
Explanation:
When Mendel's laws of genetics became well known the laws of genetics created a major problem for Darwin's theory of descent with modification. Neo Darwinism is an attempt to solve the problem that Mendel's laws of genetics created for Darwin's theory of evolution through natural selection and infinite possible variations in organisms.
Darwin's theory of descent with modification required infinite possible variations for natural selection to act upon. Natural selection can only chose between existing variations. Natural selection can not create variations. Mendel's laws of genetics proved that sexual and asexual reproduction are essentially conservative. No new variation are created by the normal actions of genetics. If Mendel's laws were true and the only forces acting on organisms then Darwin's theory was false.
Neo Darwinism attempts to solve this problem by the use of mutations to explain the source of variations necessary for Natural selection to act. Mutations which are random accidental changes in the DNA create new variations in organisms. Examples are blue eyes, white skin, six toed cats, and blind cave fish.
Neo Darwinism claims that these random accidental changes are sufficient to explain how an increase in information and complexity can occur. The accidental changes are supposed to be the raw material that natural selection has used to move the organic world from the simple to the complex. ( descent with modification)
For over 100 years scientists have studied mutations and have not discovered any empirical evidence that accidental changes can result in new information that is more complex. No new viable life forms have been created by mutations formed in the laboratories. Shannon's Laws of information applied to DNA imply that mutations can not create new information. The copying and transfer of information is governed by the second law of thermodynamics that informations goes from the complex to the less complex or simple. That is usable information is always lost.
Neo Darwinism is an attempt to solve the problem for Darwin's theory created by the discovery of Mendel's laws of genetics. Neo Darwinism attempts to solve the problem by using De Vrie's theory of mutations.
