(2015) analyzed genomes from males from western Georgia, in the Caucasus, from the Late Upper Palaeolithic (13,300 years old) and the Mesolithic (9,700 years old). These two males carried Y-DNA haplogroup: J* and J2a, later refined to J1-FT34521, and J2-Y12379*, and mitochondrial haplogroups of K3 and H13c, respectively.[9] Their genomes showed that a continued mixture of the Caucasians with Middle Eastern populations took place up to 25,000 years ago, when the coldest period in the last Ice Age started.[4]