Part 2:  Finding SNPs differing between populations and filtering for those that may be phenotype-associated.

1. Sum up allele counts for Caucasians and Africans
2. Filter the gd_snp datase using a complex expression to get SNPs fixed on opposite alleles
3. Further filter the SNPs to those in regions of diminished variation through clustering
4. Finding coding SNPs: using the aaChanges tool
5. Finding non-coding SNPs: intersecting with ENCODE DNase hypersensitive sites and transcription factor occupied segments