natural selection  
noun
1.
the process by which forms of life having traits that better enable them to adapt to specific environmental pressures, as predators, changes in climate, or competition for food or mates, will tend to survive and reproduce in greater numbers than others of their kind, thus ensuring the perpetuation of those favorable traits in succeeding generations.
 
 
 
Take this away from various groups in a species, by ensuring that those disadvantaged groups; survive famine ( by supplying them with all the food they need ), draught ( by supplying them with all the water they need ) and War ( by giving them all shelter in places of safety, with other groups )......and ultimately you ensure the end of the entire species. It's as certain as overcoming death itself, without curtailing the creation of life..........would mean ONE Planet.........THIS Planet.......simply wouldn't provide enough room...........that's a FACT !!