WEBVTT 00:00:00.170 --> 00:00:11.819 (MUSIC). Have you noticed that you're different to your relations, parents, or carers, 00:00:12.199 --> 00:00:13.449 your next door neighbor, 00:00:13.810 --> 00:00:15.600 the kid who lives across the street, 00:00:15.819 --> 00:00:17.489 and everyone else on the planet? 00:00:18.290 --> 00:00:20.260 In fact, you're unique. 00:00:21.250 --> 00:00:23.639 But do you really know why you are different? 00:00:24.270 --> 00:00:26.309 Why are we all different to each other? 00:00:26.870 --> 00:00:31.309 Why does any organism have different characteristics to another organism? 00:00:32.369 --> 00:00:37.450 The answer lies in a long-running debate called nature versus nurture, 00:00:37.799 --> 00:00:40.229 or genetics versus environment, 00:00:40.630 --> 00:00:42.110 which is a little less catchy. 00:00:43.669 --> 00:00:46.020 Nature refers to our genetics. 00:00:46.349 --> 00:00:49.549 The unique combination of genes that we have naturally 00:00:49.560 --> 00:00:53.119 inherited from our biological parents from their DNA. 00:00:54.419 --> 00:00:57.409 Many characteristics are controlled by our genes, 00:00:57.669 --> 00:00:59.110 including our blood group, 00:00:59.479 --> 00:01:01.759 eye color, or natural hair color. 00:01:02.830 --> 00:01:05.769 Some diseases are also caused by our genes. 00:01:06.180 --> 00:01:08.290 For example, cystic fibrosis. 00:01:09.059 --> 00:01:13.349 The color of a flower or a fruit is controlled by genes in plants. 00:01:14.169 --> 00:01:18.550 Nurture refers to the effect of the environment on characteristics. 00:01:19.290 --> 00:01:21.430 The word literally means care. 00:01:22.800 --> 00:01:26.739 Examples of characteristics that are determined by the environment 00:01:27.010 --> 00:01:28.639 are weight or mass, 00:01:28.900 --> 00:01:30.760 which is dependent on your diet 00:01:30.870 --> 00:01:32.400 or the presence of a scar. 00:01:33.139 --> 00:01:39.199 Some diseases may be caused by environmental influences such as type 2 diabetes 00:01:39.370 --> 00:01:41.040 or coronary heart disease. 00:01:41.980 --> 00:01:45.440 Imagine a plant has not received enough sunlight or water, 00:01:46.269 --> 00:01:48.680 this may influence the height of the plant 00:01:48.989 --> 00:01:50.839 or the number of fruits produced. 00:01:51.779 --> 00:01:56.139 We would say that the environment has influenced these characteristics too 00:01:56.680 --> 00:01:59.839 or that a plant has been affected by nurture. 00:02:00.839 --> 00:02:02.760 Can you decide if each of these 00:02:02.769 --> 00:02:06.230 characteristics is controlled by inherited characteristics, 00:02:06.459 --> 00:02:08.258 the environment, or both? 00:02:08.899 --> 00:02:11.330 Where would each go on a Venn diagram? 00:02:11.649 --> 00:02:13.479 Pause the video while you think. 00:02:17.179 --> 00:02:18.449 Did you get them all right? 00:02:20.220 --> 00:02:22.929 The effect of genetics and the environment on 00:02:22.940 --> 00:02:26.869 characteristics has been researched using identical twins. 00:02:27.899 --> 00:02:29.360 Can you think why this is? 00:02:31.419 --> 00:02:34.270 Identical twins have identical DNA, 00:02:34.830 --> 00:02:38.199 so in theory, should have identical characteristics. 00:02:39.100 --> 00:02:43.119 It follows that any differences between a pair of identical twins 00:02:43.250 --> 00:02:47.589 could be due to the influence of the environment on their characteristics. 00:02:48.759 --> 00:02:49.639 In fact, 00:02:49.649 --> 00:02:52.259 twins often grow up to have very different 00:02:52.270 --> 00:02:56.500 personalities and preferences beyond their physical similarities. 00:02:57.729 --> 00:03:01.190 These studies showed that many characteristics are 00:03:01.199 --> 00:03:04.630 influenced by both genetics and the environment. 00:03:06.639 --> 00:03:11.820 Some studies actually used twins identical genomes as a control 00:03:11.830 --> 00:03:14.460 to prove the effect of the environment on the body. 00:03:15.710 --> 00:03:16.729 For example, 00:03:16.929 --> 00:03:19.949 one study showed how skin aged differently 00:03:19.960 --> 00:03:23.509 by comparing smoker twins with non-smoker twins. 00:03:24.570 --> 00:03:27.869 Remember that the characteristics of a living organism 00:03:28.080 --> 00:03:32.660 are influenced by its genetics and its interaction with the environment, 00:03:33.089 --> 00:03:34.229 so both nature 00:03:34.360 --> 00:03:36.309 and nurture are responsible. 00:03:38.869 --> 00:03:40.979 Please like and share our videos with your friends. 00:03:40.990 --> 00:03:44.220 If you have any questions that you want help with, just comment below.