A new paper in Proceedings of the Royal Society dovetails with some posts I’ve put up on the peopling of Japan of late. The paper is Bayesian phylogenetic analysis supports an agricultural origin of Japonic languages:
Languages, like genes, evolve by a process of descent with modification. This striking similarity between biological and linguistic evolution allows us to apply phylogenetic methods to explore how languages, as well as the people who speak them, are related to one another through evolutionary history. Language phylogenies constructed with lexical data have so far revealed population expansions of Austronesian, Indo-European and Bantu speakers. However, how robustly a phylogenetic approach can chart the history of language evolution and what language phylogenies reveal about human prehistory must be investigated more thoroughly on a global scale. Here we report a phylogeny of 59 Japonic languages and dialects. We used this phylogeny to estimate time depth of its root and compared it with the time suggested by an agricultural expansion scenario for Japanese origin. In agreement with the scenario, our results indicate that Japonic languages descended from a common ancestor approximately 2182 years ago. Together with archaeological and biological evidence, our results suggest that the first farmers of Japan had a profound impact on the origins of both people and languages. On a broader level, our results are consistent with a theory that agricultural expansion is the principal factor for shaping global linguistic diversity.
I don’t know the technical details of linguistics to comment, but the alignment between the linguistic model and archeology is pretty impressive to me. There’s a 95% confidence interval which can push the time back to 4,000 years, so there’s some fudge factor too. The basic technique is borrowed from phylogenetics. This is pretty clear when you notice that one of the algorithms seems to be the same one used in the rice genomics paper. Nick Wade covers the paper in The New York Times, so no need for me to give a blow-by-blow in a domain where I don’t have much insight anyway.
Randy McDonald just pointed me to a 2008 paper in AJHG, Japanese Population Structure, Based on SNP Genotypes from 7003 Individuals Compared to Other Ethnic Groups: Effects on Population-Based Association Studies. It speaks to an issue I brought up earlier in my post, Sons of the farmers, the story of Japan, which describes the ethnogenesis of the Japanese modern people from the Yayoi culture. The Yayoi presumably brought rice from the Asian mainland, probably from what is today southern Korea. But the Japanese islands were not uninhabited before this period. Japan was home to the Jomon culture, which has a rather storied history in the annals of archaeology. The Jomon seem to have been a predominantly hunter-gatherer population which was also sedentary, and engaged in the production of objects such as pottery which are normally associated with more advanced farming societies. I have a difficult time crediting the ~13,000 year period of continuous development which is attributed to the Jomon, but, it does seem likely that the period between 2,000 and 2,500 years before the present did mark a sharp cultural discontinuity in the Japanese islands, as Jomon gave way to Yayoi.
A related issue to this indisputable cultural shift is the question of whether it was accompanied by a demographic transition. This particular debate is fraught with politics, but we have enough genetic information that we can hazard a tentative guess. It does look like the Jomon-Yayoi cultural shift was accompanied by a significant demographic transition. In particular, the Ainu of the north and the inhabitants of the Ryukyu islands in the south seem distinctive from the majority of Japanese who inhabit the core islands. The hypothesis that these peoples are more related to the Jomon, or directly descended from them. One must distinguish these two groups though; the Ainu remained culturally distinctive from the Japanese, in lifestyle and language before their de facto absorption into the Japanese of late. In contrast, the people of the Ryukyus today seem to be clearly related to the southern Japanese in both language and lifestyle. If the Ryukyu islanders preserve more of the Jomon ancestral heritage, it may simply be due to the dilution of the signal of the original Yayoi pioneers as they moved south.
But there is another piece of the puzzle which has always been a point of curiosity for me: what happened to the non-Japanese populations of northern Honshu? Termed Emishi, these people retained a distinctive identity in northern Honshu until ~1,000 years ago. Fragmentary references in the historical texts make it clear that these people did not speak Japanese natively, and were physically different in appearance, being a “hairy” and “bearded” people. This is how the Ainu were also described, and because of the Emishi’s geographical proximity to Hokkaido it is presumed there may have been a cultural continuity. It turns out that the 2008 paper hints at the genetic imprint of the Emishi.
Ainu in 19th century Hokkaido, and rice paddies
Unlike some islands Japan has a long history of human habitation. More interestingly, under the Jomon culture the Japanese archipelago was home to one of the earliest, if not the earliest, societies which used pottery. The Jomon do not seem to have been intensive agriculturalists. Rather, with a widespread marine littoral they likely maintained extremely high population densities, and at least semi-sedentary habitation patterns, simply through a hunting & gathering mode of production. Pacific Northwest Amerindians are likely a good analogy. They also relied on a dense stock of marine life to maintain population densities of a high level and a sedentary lifestyle.
About 2,000 years ago the Yayoi people arrived in Japan. The first Yayoi settlements are in northern Kyushu. These people brought intensive agriculture, in particular rice agriculture, to the Japanese archipelago. The general assumption is that the Yayoi are the precursors of the Japanese who entered into the international system of East Asia during the Tang dynasty in the second half of the first millennium. The Ainu of Hokkaido are presumed to be the descendants of the remaining Jomon people, maintaining a hold in the northern island because of its ecological unsuitability to Japanese agriculture.
The question is: what proportion of the ancestry of modern Japanese is Jomon/Ainu, and what proportion is Yayoi? The dynamics here are nicely constrained by the fact that Japan is a relatively isolated island system. The Yayoi seem to have arrived at one discrete moment in history, and rapidly expanded in ~1,000 years to all the main islands of Japan, though the full settlement of Hokkaido commenced in the 19th century. Interestingly, parts of northern Honshu seem to have had a distinct post-Jomon culture down to ~1000 AD.
Conveniently the HapMap has both Japanese and Chinese samples, but often there hasn’t been too much focus on the differences between these two groups because they’re very close in a global context when compared to the Yoruba or Europeans. In more recent analyses of East Asian groups the coverage seems to be better with various Chinese ethnic groups, but relatively few samples from Siberian populations. The latter are critical because the supposition is that these are the groups which would have the most affinities with the Jomon, due to the culture and contacts of the Ainu which evident during the modern period.
Dienekes most recent post on K = 15 ancestral components in ADMIXTURE clarifies some issues in this regard. There are multiple Han Chinese and Japanese samples, as well as a wide range of East Asian and Siberian groups. I’ve reedited and formatted K = 15 a bit, with the aim of focusing on the relationships of the Japanese in particular.
Dienekes Pontikos ruminates on the changes in human genetic variation on a world-wide scale over the past 10,000 years based on an MDS plot of East Eurasian genetic variation which he generated. I’ve taken his plot and added geographical labels, so you can see the difference in scale between geography and genetics in terms of distance:
A rather depressing piece in The New York Times, Japan, Once Dynamic, Is Disheartened by Decline:
But perhaps the most noticeable impact here has been Japan’s crisis of confidence. Just two decades ago, this was a vibrant nation filled with energy and ambition, proud to the point of arrogance and eager to create a new economic order in Asia based on the yen. Today, those high-flying ambitions have been shelved, replaced by weariness and fear of the future, and an almost stifling air of resignation. Japan seems to have pulled into a shell, content to accept its slow fade from the global stage.
Yet Japan’s demographic and economic stagnation seems to be the ultimate likely outcome if Z.P.G. activists get their way. All things equal if I had to pick between being a citizen of a dynamic but poor society or a stagnant but rich one, I’d go with the latter. The moral of the article is that Japan’s fate may await Western nations, but is affluent ennui that bad? Perhaps we are destined to become as the citizens of Diaspar.
The New York Times gives an impressionistic sense of Japanese decline, and relies on the perceptions of the Japanese themselves. But let’s look at some numbers. Below are some plots from Google Data Explorer with national aggregate statistics. They’re comparing Japan, the USA, and Germany, over time.
One of the podcasts I subscribe to is Thinking Allowed from Radio 4. The most recent one was on the role which robots are envisaged to play in the future of Japan:
Also, the rise of the ‘fembot’. The Japanese government is investing billions in the development of robotic technology. They think the robot will do for the 21st century economy what the automobile did for the 20th. However, Jennifer Robertson thinks that as female robots are developed to perform some of the functions traditionally performed by women, it bodes ill for the future of Japanese society.
The guest was very negative about Japan’s plan to substitute robots for immigrants. Basically, she perceived that there was a risk that the Japanese were going to turn into technologically enabled inward-looking xenophobes, closing themselves off to the rest of the world and interacting only with their robot minions. If so, it’s their right as a nation to do so, and I don’t see why all nations should adopt the same policies in regards to globalization. It isn’t as if Japan’s Human Development Index was similar to that of North Korea.
Though science fiction has a generally bad track record as prediction, I couldn’t help but think of Isaac Asimov’s Spacer society of Solaria, from his Robot Series. There’s already a fair amount of media reports about antisocial personality disorders becoming very common in Japan, the sort of stuff that Asimov describes as normal on Solaria. Here is Wikipedia description of the Spacer worlds, of which Solaria was the most extreme case:
In Isaac Asimov’s Foundation/Empire/Robot series, the Spacers were the first humans to emigrate to space. About a millennium thereafter, they severed political ties with Earth, and embraced low population growth and extreme longevity (with lifespans reaching 400 years) as a means for a high standard of living, in combination with using large numbers of robots as servants. At the same time, they also became militarily dominant over Earth.
In many ways the Spacers, and what Japan aims to become, seems to be the realization of what the ZPG movement was pushing for in the 1970s. I’m moderately skeptical that they can pull it off as a practical matter, projections of the feasibility of humanoid robots have been overly optimistic for decades, but it would be an interesting development for a nation which prides itself on its peculiar distinctiveness to be the first to “merge” man and machine into a social ecology.
Image Credit: Wikimedia