1. ARISTORTAL,
Aristortal is the first one who classify organisms scientifically . He divided organisms as PLANTS and ANIMALS.
Animals were further divided according to the criteria such as,
* Mode of locomotion
* Reproduction
* Presence and absence of red blood cells
2.EARNEST HAECKEL
He introduce kingdom protista and Taxam Phylum
3.ROBERT WHITAKER
He classify organisms into 5 kingdoms based on 3 criteria
1.Cellular organization
2. Arrangement of cells
3. Mode of transport
4. CARLWOUS
After the acceptation of DARWIN theory on evolution and with the advancement of molecular biology it became apparent that in early stages of evolution