Immigration or Selective Genetic Migration

While living in Canada I came across many highly specialized immigrants who were performing in very minor duties. There are literally thousands of Doctors, Engineers and teachers who are working as cab drivers, pizza delivery drivers , night security officers and floor cleaners. What is more interesting is that these individuals are given preference when choosing who to give landed immigrancy status. Its a simple point form application, the more educated and accomplished you are the higher number of points you get in this application and hence, the higher chance that you will be chosen as an visa candidate. That is the general rule to get into Canada, I can only assume that, except for the US lottery system, most of the western world's immigration application follows suit.
Now the question is WHY? why give visa to an applicant who is highly specialized to come over here and be a general worker? In Canada they have been promising for years that they are forming legislations that will help integrate these people into the society in their working professions. It has not happened yet. Is there another reason?

Lets take a closer look at the African Americans in the USA for a second. Have you noticed that they are highly accomplished as Singers, Musicians, Sportsman? Have you noticed that this pattern is not as evident in their continent of origin, Africa? This is a classic example of Selective Genetic migration. Who did the original slavers choose as slaves? They selectively chose physically healthy and strong individuals, people who could provide entertainment ie singers and dancers. These are the people that they brought over to North America as slaves. Since, for the most part, racial intermixing was very minimal, what we see today, to an extent, can be said to be selective genetic breeding. What I mean by this is that this particular community of people got to mix genes only with each other for over 200 years. The product of this mixing is clearly evident.

What could be the benefit of having a doctor work as a cab driver? how could the community as a whole benefit from this? It can. Not at this moment, but this individuals good genes will remain here to mix with other "good genes". We literally have an inflow of good genes into these western countries. This is a controversial statement because it assumes other third world countries don't have good genes but lets face the facts here. The best of those other countries are being cherry picked to live in the west. This is a classic example of Selective Genetic migration.

To What end is the next question. Does this mean that the western countries will eventually produce more intelligent people? I don't know the answer to that question. If genetic migration created the phenomenon that we observe in African Americans, its not too far fetched to think that it will have some sort of an effect in the future. That remains to be seen.