fig6350300250200150100500Y Chromosome Lineages-2700-2500-2300-2100-1900-1700-1500-1300-1100-900-700-500-300-10010030050070090011001300150017001900(B.C.) Years (A.D.)Global Population Size (Male)1,600,000,0001,400,000,0001,200,000,0001,00,000,000800,000,000600,000,0000200,000,000400,000,000