7. Heredity & Evolution
Evolution (L.evolvere – to unfold) or organic evolution (Spencer, 1852) is the unfolding of nature wherein newer types of organisms develop from the pre-existing ones through modification.
Acquired Traits :
Acquired traits are those variations which an individual develops during its life time due to effect of environmental factors, use and disuse of organs and conscious efforts.
Theory of Inheritance of Acquired Characters (Lamarckism) : It is the first theory of evolution that was proposed by French biologist Jean Baptiste de Lamarck. It is based on the following
Internal Vital Force : There is a vital force in organisms which rends to change them, generally making them larger and more complex.