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