Theories of Evolution,homework help

Various theories have been postulated by different evolutionists. Most important ones are;

1-Lamarcks theory of inheritance of acquired characters(Lamarckism)

2-Darwin theory of natural selection (Darwinism)

LAMARCKISM (Theory of inheritance of Acquired Characters):-

This theory was proposed by French biologist Lamarck in 1809.It is popularly known as ’The inheritance of Acquired Characters in Organisms’ and comprises of four assumptions-

1. Living organisms and their parts tend to increase in size continuously due to internal forces of life(Origin of need).

2. Formation of new organ in the body of an organisms is the result of a new need and new movement which this need initiates and maintains in the body(Effect of need).

3. If an organ is used continuously and constantly it will tend to become highly developed, whereas disuse results in its degeneration (Use and Disuse).

4. Modifications acquired during the life time of an individual are inherited by its offspring. It means that changes are cumulative over a period of time(Inheritance of Acquired characters).