It focused narrowly on areas in and around active genes, ignoring the 98.5% of genomic material known as "junk DNA." This process pinpointed 25, 000 genetic landmarks called SNPS (single nucleotide polymorphisms, or "snips"), places where a single dna letter varies from one person to the next.

FORBES: The Suggestive Gene

As a first step, the scientists examined half a million genetic markers in the participants' DNA. These markers, known as single nucleotide polymorphisms, or SNPs, can together reveal how genetically similar people are, even though they are not conventionally related.

WSJ: Intelligence Changes Linked to Genes

But DNA chip technology for scanning these so-called single nucleotide polymorphisms, or SNPs ("snips"), was prohibitively expensive in 2000.

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