The analysis of population structure has many methods that one of them is PCA in population genetic research. You know, "genotype-environment correlation" is really important. For example, we are two populations (breed) in two different locations with their genotyping and geographic data (e.g. elevation, latitude, longitude, temperature, rainfall, and so on). However, why researchers don't combine geographic data with genotyping data for calculating PCA? What is your opinion about this subject? or Do you read papers on this subject?
I will really appreciate if you guide me.