THEORY OF EVOLUTION, PUNCTUATED
EQUILIBRIUM AND GRADUALISM
Jean Baptide de Lamarck: explained his theory of evolution using
two laws:
The law of use and disuse:
• As an organism uses its organ more frequently, the used organ
more developed
• As an organism doesn’t use its organ more frequently the unused
organ become less developed or may disappear altogether.
The law of acquired traits:
• Traits acquired during life time of an individual
• Can be passed to the next offspring.
Charles Darwin: explained his theory of evolution using natural
selection:
• Organisms produce large number of offspring
• Which show great deal of variation
• Some have favourable traits
• While others have unfavourable traits
• Due to environmental changes which introduces competition
amongst these offspring
• Offspring with favourable traits survive while those with
unfavourable traits die out
• This is natural selection
• The survived offspring will interbreed and their genotypes are
exchanged.
EQUILIBRIUM AND GRADUALISM
Jean Baptide de Lamarck: explained his theory of evolution using
two laws:
The law of use and disuse:
• As an organism uses its organ more frequently, the used organ
more developed
• As an organism doesn’t use its organ more frequently the unused
organ become less developed or may disappear altogether.
The law of acquired traits:
• Traits acquired during life time of an individual
• Can be passed to the next offspring.
Charles Darwin: explained his theory of evolution using natural
selection:
• Organisms produce large number of offspring
• Which show great deal of variation
• Some have favourable traits
• While others have unfavourable traits
• Due to environmental changes which introduces competition
amongst these offspring
• Offspring with favourable traits survive while those with
unfavourable traits die out
• This is natural selection
• The survived offspring will interbreed and their genotypes are
exchanged.
