1 00:00:00,320 --> 00:00:02,190 In this lesson we've learned just a teeny bit 2 00:00:02,190 --> 00:00:05,210 more about ways we can trace through our maternal 3 00:00:05,210 --> 00:00:08,560 or paternal lines. So in the case of mitochondrial 4 00:00:08,560 --> 00:00:11,870 DNA we only inherit that from our mothers. So 5 00:00:11,870 --> 00:00:14,390 you can trace your maternal line back through the 6 00:00:14,390 --> 00:00:18,270 mitochondrial DNA. The mitochondria have been passed down from 7 00:00:18,270 --> 00:00:22,070 generation to generation. From great-great-great grandmother to great-great to 8 00:00:22,070 --> 00:00:25,530 great to grandmother to mother to you. Now the 9 00:00:25,530 --> 00:00:28,820 same thing is true for the Y chromosome for males. 10 00:00:28,820 --> 00:00:31,950 Every male is genetically XY and he had to have 11 00:00:31,950 --> 00:00:34,430 gotten that Y chromosome from his father, who got it 12 00:00:34,430 --> 00:00:36,630 from his father who got it from his father, who 13 00:00:36,630 --> 00:00:39,260 got it from his father, and so this Y chromosome 14 00:00:39,260 --> 00:00:43,110 has just been passed down. From generation to generation, through 15 00:00:43,110 --> 00:00:45,910 all of the male line. One of the big distinctions 16 00:00:45,910 --> 00:00:50,550 here, is that Mitochondrial DNA, everybody has. But the Y 17 00:00:50,550 --> 00:00:54,910 chromosome, only males have. We're going to revisit these 18 00:00:54,910 --> 00:00:58,060 concepts a little bit later, in lesson seven. 19 00:00:58,060 --> 00:01:00,300 When we actually try to trace an individual's 20 00:01:00,300 --> 00:01:03,330 lineage, on both his mother's and father's side.