They might improve it because you eat it everyday. If you eat it everyday, it should be healthy and nutritious. They aren't going to want to make bad food that kids eat everyday, end up putting in something not good or healthy, then getting sued. They are going to make the best quality food.
~Silver
        
             
        
        
        
The answer is reproductive isolation. Reproductive isolation ensures members of different species do not produce offspring. In this case, geographical separation is ensuring that individuals from the two different populations are not able to mate with each other. Eventually, through different selective pressures, the two populations will diverge sufficiently in genotype to become distinctly different.
        
             
        
        
        
Hello, that is a very good question!
Back then there was no such thing as 'birth-control', hence they never actually prevented pregnancies, of course there were services that provided 'different' penetration but that could also result in pregnancies.
The popular method of not giving birth [prevent pregnancy] was to kill the baby while still carrying [termination], in other words have a miscarriage. 
There many various methods during that time (herbs, beating, old cloth hanger). 
Hope this helped,
j548831
 
        
             
        
        
        
For evolution to occur:
There must be genetic variation in a population. This provides variation on which natural selection can act. Then natural selection can act by selecting those species which are better adapted to the environmental conditions. Over time those animals that are best suited to the environment only will survive and reproduce. Those organisms successful genes will be preserved and eventually the gene frequency in the population will change, changing the overall characteristics of a population. This is how evolution occurs.