Natural Selection Vs Human Evolution

Evolution is the changing of gene frequency in a population over time.
Natural selection is where animals with advantageous characteristics produce more offspring, therefore passing down favoured genes. In the more developed parts of the world, medical care and access to food means natural selection is lesser, as selective forces that were there before e.g some diseases and predators, are no longer there. Therefore, some humans that have characteristics that would have previously meant they produce less offspring, reproduce at a similar rate to humans with more advantageous characteristics.
However, in many parts of world selective forces leading to natural selection are still prevalent. Where easy access to medical care and food is not there,
Evolution of humans can occur from mutations and migrations of genes and people. Genetic drift occurs when by chance, one human has more offspring then another, so their hereditary characteristics are passed on to more people, whether these characteristics be advantageous or not. These are then passed on further, leading to a ‘drift’ in the characteristics of humans, a part of evolution.
Behavioural evolution is the adaptation of behaviour rather than genetic adaptation through natural selection, to combat environmental forces. E.g agricultural advances such as keeping animals, leading to easier access to food. During Neolithic revolution when humans began to use agriculture for food production, rather than previous hunter-gatherer techniques meant selective forces on human evolution changed, as different characteristics became more desirable. E.g. the gene that helps digest starch is more prevalent in populations where agriculture was favoured.
Human physiology also leads to adaptation of many stresses. E.g. fat storage. However, if behavioural and physiological fail, rates of reproduction is effected, therefore natural selection does take place, and therefore