Lamarckism is the first theory of evolution , which was proposed by Jean Baptiste de Lamarck, a French biologist and was explained in his famous book Philosophie Zoologigue (1809). It includes four main propositions: Internal vital force, Effect of environment and new needs, use and disuse of organs, inheritance of acquired characters. Following are the examples which explain Lamarck theory.
Examples Explaining Lamarck’s theory
a) Long neck and high forelimbs of giraffe developed due to their stretching for obtaining foliage from trees when ground vegetation became sparse is the prime example of Lamarckism.
Evolution of long neck in giraff as per use and disuse of organs
b) Development of webbed feet in aquatic birds, like duck. They were considered to have arisen from the terrestrial ancestors.
c) Bottom dwelling flat fish whose larvae have normal eyes while in adults, eyes migrate to one side of the head.
d) Ancestors of snake were lizard like reptiles with two pairs of fully developed limbs. They acquired elongated limbless body for the sake of protection.
e) Evolution of flightless birds from their flying ancestors.
f) Development of speed in deer through continuous efforts of running in order to protect itself from enemies.
g) Claws of carnivorous mammals are well adapted for their carnivorous habits.
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