1 00:00:00,170 --> 00:00:11,819 (MUSIC). Have you noticed that you're different to your relations, parents, or carers, 2 00:00:12,199 --> 00:00:13,449 your next door neighbor, 3 00:00:13,810 --> 00:00:15,600 the kid who lives across the street, 4 00:00:15,819 --> 00:00:17,489 and everyone else on the planet? 5 00:00:18,290 --> 00:00:20,260 In fact, you're unique. 6 00:00:21,250 --> 00:00:23,639 But do you really know why you are different? 7 00:00:24,270 --> 00:00:26,309 Why are we all different to each other? 8 00:00:26,870 --> 00:00:31,309 Why does any organism have different characteristics to another organism? 9 00:00:32,369 --> 00:00:37,450 The answer lies in a long-running debate called nature versus nurture, 10 00:00:37,799 --> 00:00:40,229 or genetics versus environment, 11 00:00:40,630 --> 00:00:42,110 which is a little less catchy. 12 00:00:43,669 --> 00:00:46,020 Nature refers to our genetics. 13 00:00:46,349 --> 00:00:49,549 The unique combination of genes that we have naturally 14 00:00:49,560 --> 00:00:53,119 inherited from our biological parents from their DNA. 15 00:00:54,419 --> 00:00:57,409 Many characteristics are controlled by our genes, 16 00:00:57,669 --> 00:00:59,110 including our blood group, 17 00:00:59,479 --> 00:01:01,759 eye color, or natural hair color. 18 00:01:02,830 --> 00:01:05,769 Some diseases are also caused by our genes. 19 00:01:06,180 --> 00:01:08,290 For example, cystic fibrosis. 20 00:01:09,059 --> 00:01:13,349 The color of a flower or a fruit is controlled by genes in plants. 21 00:01:14,169 --> 00:01:18,550 Nurture refers to the effect of the environment on characteristics. 22 00:01:19,290 --> 00:01:21,430 The word literally means care. 23 00:01:22,800 --> 00:01:26,739 Examples of characteristics that are determined by the environment 24 00:01:27,010 --> 00:01:28,639 are weight or mass, 25 00:01:28,900 --> 00:01:30,760 which is dependent on your diet 26 00:01:30,870 --> 00:01:32,400 or the presence of a scar. 27 00:01:33,139 --> 00:01:39,199 Some diseases may be caused by environmental influences such as type 2 diabetes 28 00:01:39,370 --> 00:01:41,040 or coronary heart disease. 29 00:01:41,980 --> 00:01:45,440 Imagine a plant has not received enough sunlight or water, 30 00:01:46,269 --> 00:01:48,680 this may influence the height of the plant 31 00:01:48,989 --> 00:01:50,839 or the number of fruits produced. 32 00:01:51,779 --> 00:01:56,139 We would say that the environment has influenced these characteristics too 33 00:01:56,680 --> 00:01:59,839 or that a plant has been affected by nurture. 34 00:02:00,839 --> 00:02:02,760 Can you decide if each of these 35 00:02:02,769 --> 00:02:06,230 characteristics is controlled by inherited characteristics, 36 00:02:06,459 --> 00:02:08,258 the environment, or both? 37 00:02:08,899 --> 00:02:11,330 Where would each go on a Venn diagram? 38 00:02:11,649 --> 00:02:13,479 Pause the video while you think. 39 00:02:17,179 --> 00:02:18,449 Did you get them all right? 40 00:02:20,220 --> 00:02:22,929 The effect of genetics and the environment on 41 00:02:22,940 --> 00:02:26,869 characteristics has been researched using identical twins. 42 00:02:27,899 --> 00:02:29,360 Can you think why this is? 43 00:02:31,419 --> 00:02:34,270 Identical twins have identical DNA, 44 00:02:34,830 --> 00:02:38,199 so in theory, should have identical characteristics. 45 00:02:39,100 --> 00:02:43,119 It follows that any differences between a pair of identical twins 46 00:02:43,250 --> 00:02:47,589 could be due to the influence of the environment on their characteristics. 47 00:02:48,759 --> 00:02:49,639 In fact, 48 00:02:49,649 --> 00:02:52,259 twins often grow up to have very different 49 00:02:52,270 --> 00:02:56,500 personalities and preferences beyond their physical similarities. 50 00:02:57,729 --> 00:03:01,190 These studies showed that many characteristics are 51 00:03:01,199 --> 00:03:04,630 influenced by both genetics and the environment. 52 00:03:06,639 --> 00:03:11,820 Some studies actually used twins identical genomes as a control 53 00:03:11,830 --> 00:03:14,460 to prove the effect of the environment on the body. 54 00:03:15,710 --> 00:03:16,729 For example, 55 00:03:16,929 --> 00:03:19,949 one study showed how skin aged differently 56 00:03:19,960 --> 00:03:23,509 by comparing smoker twins with non-smoker twins. 57 00:03:24,570 --> 00:03:27,869 Remember that the characteristics of a living organism 58 00:03:28,080 --> 00:03:32,660 are influenced by its genetics and its interaction with the environment, 59 00:03:33,089 --> 00:03:34,229 so both nature 60 00:03:34,360 --> 00:03:36,309 and nurture are responsible. 61 00:03:38,869 --> 00:03:40,979 Please like and share our videos with your friends. 62 00:03:40,990 --> 00:03:44,220 If you have any questions that you want help with, just comment below.