0:00:01.193,0:00:02.127 When you marry, 0:00:02.127,0:00:06.811 usually you take on your partner's surname[br]or your parter takes on yours. 0:00:06.811,0:00:09.057 Two people with different surnames become 0:00:09.057,0:00:10.867 two people with the same. 0:00:10.867,0:00:13.566 One surname spreads, the other one goes... 0:00:13.566,0:00:15.266 ...extinct? Usually not. 0:00:15.266,0:00:17.350 There might be siblings, cousins, 0:00:17.350,0:00:19.510 strangers who happen to share the surname, 0:00:19.511,0:00:22.271 to carry it on for the one who lost it. 0:00:22.271,0:00:25.199 But if one person fails to pass on the surname, 0:00:25.199,0:00:27.327 so might the others. 0:00:27.327,0:00:29.200 In fact, every now and then 0:00:29.200,0:00:31.932 entire surnames do go extinct 0:00:31.932,0:00:33.982 when its last bearer passes away 0:00:33.995,0:00:35.835 without passing it on. 0:00:36.011,0:00:37.681 According to the Daily Mail, 0:00:37.681,0:00:40.949 in England and Wales, 200,000 surnames 0:00:40.949,0:00:43.109 were lost since 1901. 0:00:43.213,0:00:45.143 You can find lists of endangered surnames 0:00:45.148,0:00:48.688 on websites such as Ancestry.com and myheritage.com 0:00:48.868,0:00:51.178 Ancestry counts surnames with less than 0:00:51.184,0:00:53.884 50 carriers left as endangered, 0:00:53.884,0:00:55.043 which in England and Wales, 0:00:55.043,0:00:56.876 would currently be names such as 0:00:56.876,0:00:59.976 Pober, Mirren, Febland (heh, Febland), 0:01:00.082,0:01:02.122 Nighy - N-Nighy? 0:01:02.480,0:01:04.860 While some of these names might be [br]more of a loss than others, 0:01:04.875,0:01:10.255 it's sad to think that they might all [br]cease to exist within a few generations. 0:01:10.394,0:01:13.904 Back in the days, new surnames [br]were created as well 0:01:13.933,0:01:18.603 based on someone's job or father's given name or where they came from. 0:01:18.641,0:01:20.941 But that doesn't really happen anymore, 0:01:20.947,0:01:22.887 not on a large scale, anyway. 0:01:22.887,0:01:25.885 So more surnames are lost than[br]new ones are being born. 0:01:25.885,0:01:28.508 Keep this experiment going long enough,[br] 0:01:28.515,0:01:33.505 and we will all end up with[br]the same surname eventually, won't we? 0:01:33.847,0:01:38.440 When we look at Earth's more ancient[br]civilizations - even more ancient- 0:01:38.440,0:01:43.310 intensive research reveals that most [br]Chinese surnames in use today 0:01:43.331,0:01:46.191 were handed down from thousands of years ago. 0:01:46.365,0:01:50.591 While historically about 12,000 [br]Chinese surnames have been recorded, 0:01:50.591,0:01:53.971 only a bit over 3,000 are currently in use, 0:01:53.971,0:01:56.975 a reduction of 75 percent! 0:01:56.987,0:02:01.897 And only a fraction of those are taking [br]over a majority of the entire population. 0:02:01.901,0:02:07.503 The three most common surnames in mainland[br]China are Li, Wang and Zhang, 0:02:07.503,0:02:12.303 which make up for more than 7 percent [br]of the Chinese population each. 0:02:12.313,0:02:15.980 Together they belong to close to[br]300 million people 0:02:15.980,0:02:19.559 and are easily the most common surnames[br]in the world. 0:02:19.559,0:02:24.429 In China, the phrase "three Zhang, four Li"[br]is used to say just "anybody." 0:02:24.441,0:02:28.051 So after thousands of years, [br]the Chinese people aren't down to 0:02:28.051,0:02:31.527 one all-dominating surname, but several. 0:02:31.527,0:02:32.687 What's going on here? 0:02:32.702,0:02:35.392 This effect can be shown in a simulation. 0:02:35.736,0:02:39.126 What you see here is the result of a [br]Galton-Watson process, 0:02:39.126,0:02:43.800 which maps out how the distribution of[br]family names changes over time. 0:02:43.800,0:02:47.116 It starts out with a very large number[br]of unique family names[br] 0:02:47.116,0:02:51.126 each represented by a different color, [br]and after 40 generations, 0:02:51.126,0:02:54.896 or around a thousand years,[br]ends with the ones which are left. 0:02:54.896,0:02:56.472 When you look at the very end there, 0:02:56.472,0:03:00.262 what you see is very similar to the Chinese situation. 0:03:00.276,0:03:03.896 The top three names take over 20 percent[br]of the cake. 0:03:04.173,0:03:07.705 But the question is: [br]if we keep the simulation going, 0:03:07.705,0:03:10.565 will we end up with only one surname? 0:03:10.872,0:03:14.562 Mathematically, the entire population does[br]converge to only one surname. 0:03:14.733,0:03:19.741 But in real life, if we start out with,[br]say, 10,000 surnames, 0:03:19.741,0:03:21.814 (and there are actually[br]much more than that) 0:03:21.814,0:03:26.276 after 40 generations we'd still be left[br]with over 400. 0:03:26.276,0:03:29.229 Okay, how about 200 generations? 0:03:29.229,0:03:31.639 Still 93 left. 0:03:31.892,0:03:35.006 While the less frequent names[br]are dying out quickly, 0:03:35.006,0:03:37.882 the more frequent ones[br]become so widely spread 0:03:37.882,0:03:41.919 that humans will probably cease to exist[br]before they do. 0:03:41.919,0:03:43.502 The probability of extinction of 0:03:43.502,0:03:47.450 a unique family name that is carried[br]by only one young couple 0:03:47.450,0:03:50.687 is 45 percent, at least in the West. 0:03:50.687,0:03:53.773 That's the average likelihood of them[br]having no children 0:03:53.773,0:03:57.843 or only children who won't pass[br]on the family name. 0:03:57.843,0:04:01.307 But the likelihood of a family name[br]which is held by multiple couples 0:04:01.307,0:04:07.567 going extinct within one generation[br]is 45 percent to the power of the number of couples. 0:04:07.572,0:04:13.121 So with a few more people sharing a surname[br]it becomes very unlikely very quickly 0:04:13.121,0:04:15.581 that this surname should disappear soon. 0:04:15.581,0:04:19.027 If you want to know how often your[br]family name is currently in use, 0:04:19.027,0:04:22.312 you can find that out on websites such as[br]Forebears. 0:04:22.312,0:04:24.552 According to the US Census Bureau, 0:04:24.552,0:04:27.261 the most common family names[br]in the US are currently 0:04:27.261,0:04:29.901 Smith, Johnson, and Williams, 0:04:29.901,0:04:34.836 which together make up for around[br]2 percent of the entire US population. 0:04:34.836,0:04:37.841 That's, of course, not very impressive[br]to China. 0:04:37.841,0:04:41.998 In a way, you could say that [br]on this timeline, the US is somewhere here 0:04:41.998,0:04:44.845 while China is already over there. 0:04:44.845,0:04:48.572 As fewer family names[br]become more widely spread, 0:04:48.572,0:04:53.082 we might follow the Chinese feat and[br]become more creative about given names. 0:04:53.082,0:04:54.900 So instead of Tim Smith, [br] 0:04:54.900,0:04:57.950 you might be called the[br]TalentedPeaceful Smith. 0:04:57.959,0:05:01.669 And, instead of Tom, I might be called[br]The Rest of Us.