There was an interesting hubbub about Kamau Kambon's statement that the government was keeping blacks down in order to stop that one man from having that one idea. That idea: killing all white people.
Rather than freak out because somebody wants to kill me, I actually sat down and thought for a while if there was a good way to do this.
If you made some sort of virus specialized at finding and infecting only those genes which code for white skin, well, that would certainly do something in that direction, however it doesn't help much. We have located one gene which codes for white skin and it's a single point mutation. So that matching virus would only need a single point mutation to match all people, unless it builds off the proteins created by the process. Also, there are a number of these genes within the black community. In fact, there is a mix of all genes in all communities. You can't match a single gene or group of genes to a 'race' because humans are roughly identical from a genetic standpoint, and thusly the risk is far too high. Secondly, this is just one gene and skin color is due to a collection of genes. It would cause a selective pressure against this gene by not all such genes. It would certainly darken everybody until the virus died out but would break again and quickly return to normal levels. Also, whitey has a lot at his disposal to prevent disease. So, this doesn't seem plausible. Direct conflict would also fail for fairly obvious reasons.
Well, several months have passed and I finally figured it out. In nature, as in a number of things the selection pressure of different genes differ from area to area. Sickle-cell anemia is a pretty bad disease but conveys a slight improvement in malaria resistance. As such, in areas with high malaria rates we find higher frequencies of the sickle-cell gene.
I bring up malaria for two reasons, first several months back an exceedingly impressive solution was offered. Genetically engineer the mosquitoes to be immune to the disease. Malaria not only negatively affects the humans exposed but also negatively impacts the mosquitos transmitting the disease. By genetically creating a gene for immunity, one could apply a selective pressure and push the gene into near totality, not only saving vast swaths of humans in the process, but also making creationists look like morons by using evolution to save millions of people a year.
The second reason is the solution of the first part is the solution to the second part. The trade off between traits given areas are such that in the more northern areas less skin pigment is better. The need for vitamin D is such that skin lightened to allow for more sunlight and an increase production. Whereas in other areas the darker skin prevents harm due to sunlight. I have healthy bones, but left in the sun I would turn into a lobster. For example, the Inuit people tend to have a diet consisting of good sources of vitamin D, and as a consequence their skin is darker than most people that far north, because there is less need for this evolutionary trade off.
A gene for more Vitamin D would certainly be advantageous and would destroy the advantages of lighter skin. So after the introduction of such a gene, white people would only have about 30-50 thousand years before going extinct.
The introduced gene would increase in frequency, and the lighter skin genes would then no longer serve any advantage, and would be disadvantagous (due to the decreased protection) and decrease in frequency.