Charles Darwin wrote "On the Origins of the Species" (1859) - suggesting theory of evolution explaining how species (including humans) developed
Believed creatures evolved overtime due to NATURAL SELECTION (chance) allowing 'Survival of the fittest'
Proposed natural selection repeated, new animal species emerging = evolution)
Humans evolved from animals
Richard Dawkins developed this theory. Argues individual genes adapt + evolve ("The Selfish Gene - 1976") AND organism's body = survival machine for genes