Answer:
<em>(I) Lamarckism or Theory of Inheritance of Acquired characters.</em>
This theory is based on the comparison between the contemporary species of Jean Baptiste de Lamarck's time to fossil records.
<em>(II) Darwinism or Theory of Natural Selection.</em>
Charles Darwin made an extensive study of nature for over 20 years, especially in 1831-1836 when he went on a voyage on the famous ship “H.M.S. Beagle” and explored South America, the Galapagos Islands and other islands.
<em>(III) Mutation theory of De Vries.</em>
The mutation theory of evolution was proposed by a Dutch botanist, Hugo de Vries (1848-1935 A.D.) in 1901 A.D. in his book entitled “Species and Varieties, Their Origin by Mutation”. He worked on evening primrose (Oenothera lamarckiana).
<em>(IV) Neo-Darwinism or Modern concept or Synthetic theory of evolution.</em>
The detailed studies of Lamarckism, Darwinism and Mutation theory of evolution showed that no single theory is fully satisfactory. Neo-Darwinism is a modified version of theory of Natural Selection and is a sort of reconciliation between Darwin’s and de Vries theories.
