They are connected by the Northern European plain
Answer:
migration is a strong force for equalizing the gene frequencies of sub populations in a species. Provided that the migration rate is greater than zero, gene frequencies will eventually equalize.
The correct answer is - D. It is impossible to dig through the ice on Antarctica.
Even though the technology is much more advanced nowadays than in the past, the extraction of the numerous natural resources from Antarctica is still pretty much impossible because of the ice cover over the continent.
On average, the ice is around 2 km thick on top of the landmass. Considering the fact that in order to get to the resources, the people will have to dig even more into the ground after they manage to break through the ice, makes it almost impossible, and not to mention economically unjustifiable.
