HERIDITY AND EVOLUTION : HERIDITY AND EVOLUTION EVOLUTION
The slow and gradual unfolding of organisms from pre exiting ones through changes is called evolution
EVIDENCE OF EVOLUTION : EVIDENCE OF EVOLUTION Homologous organs
Analogous organs
Vestigial organs
Fossils
Embryology
HOMOLOGOUS ORGANS : HOMOLOGOUS ORGANS Those organs which have similar structures but different functions are called homologous organs
Eg: Forelimb of birds and forelimb of man
ANALOGOUS ORGANS : ANALOGOUS ORGANS Those organs which have similar functions but different functions are called Analogous organs
VESTIGIAL ORGANS : VESTIGIAL ORGANS Those organs which are present in a body but are functionless are called vestigial organs
Eg :
Vermiform Appendix
EMBRYOLOGY : EMBRYOLOGY Study of embryos of various vertebrates reveals that during embryonic stages all the embryo looks same
FOSSILS : FOSSILS Study of certain fossils reveals some connecting links between to species
Eg : Fossils of Archaeopteryx birds shows it looks like bird but had several features which resemble reptiles too