Apidima Sapiens?

Two fossil skulls from Apidima, Greece, tell an intriguing story. The first, more than 210,000 years old, appears to be an early Homo sapiens. The second, a younger 170,000 years old, looks like a Neanderthal.

If so, then Homo sapiens moved to Greece, were replaced by Neanderthals, then thousands of years later moved back and replaced the Neanderthals (“replaced” is generally a polite word for “killed.”)

This is consistent with a fair amount of other evidence that Homo sapiens had (at least) two out-of-Africa events, of which the one that killed the Neanderthals was only the most recent. It could also represent the population wave that interbred with Neanderthals, contributing Sapiens DNA to the Neanderthal genome, well before the more famous interbreeding event when Neanderthal DNA entered our modern Homo sapiens genome.

On the other hand, there’s not a whole lot to these fossils. One is just the back of a skull. The back of a skull is more informative than it sounds on first glance because neanderthals have a bump (referred to as a “bun”) on the backs of their skulls that we don’t, but still, we’re not talking about complete skulls. So it could turn out that this was just a funny looking Neanderthal, or a piece that got pressed weirdly by a rock (the first Neanderthal skeleton people found had arthritis, which threw all of the illustrations off for decades, so these things can happen).

But throwing caution to the wind, let’s assume the skulls are correct, and so is the rough timeline I sketched out: Neanderthals inhabit Europe, Sapiens leave Africa, Sapiens push into the Middle East and Greece, Sapiens fail, Neanderthals retake the region, years pass, Sapiens try again and this time succeed, wiping out the Neanderthals.

What changed? What made the first attempt a failure and the second successful?

Aside from Sapiens generally getting smarter, I suggest a humble invention: the sewing needle.

We know from studies of lice (ew, I know) that humans began wearing clothes around 80-170,000 years ago. How do we know? Because the lice that live on our heads and the lice that infect our clothes are different species, and genetics claims that’s when they split.

The earliest known “looks like a needle” comes from Sibudu Cave, South Africa, and dates from about 61,000 years ago, but needles are small and easily broken, so I suspect that plenty were used that we haven’t found.

Neanderthals did not wear clothes–quoting Wikipedia, quoting archaeologist John F. Hoffecker:[102]

Neanderthal sites show no evidence of tools for making tailored clothing. There are only hide scrapers, which might have been used to make blankets or ponchos. This is in contrast to Upper Paleolithic (modern human) sites, which have an abundance of eyed bone needles and bone awls. Moreover, microwear analysis of Neanderthal hide scrapers shows that they were used only for the initial phases of hide preparation, and not for the more advanced phases of clothing production.

— John F. Hoffecker, The Spread of Modern Humans in Europe

Bodyhair_map_according_to_American_Journal_of_Physical_Anthropology_and_other_sourcesIf the Neanderthals did not have clothes, then they had to adapt to the European climate in other ways–probably fur.

(Incidentally, according to the only data I have on the matter, Mediterranean and Nordic peoples are oddly hairy, while Siberian people are weirdly not-hairy. If anyone has any idea why this is I’d love to hear it.)

If the first wave of Sapiens to leave Africa also did not have clothes (or had only very rudimentary clothes) and they lacked the Neanderthals’ fur, then they would have had a very difficult time surviving in the harsh European winters.

Like the Roanoke colony, the survivors may have happily gone over to the Neanderthal side.

By the time the second wave of Sapiens showed up, however, they had invented clothes–and had other elements of a more advanced cultural/technological toolkit that let them conquer the elements–and the ‘Thals.


Sunken Lands and lost Paradises: Beringia

caribou_feed_on_lichens_and_moss-_the_bird_is_an_alaskan_raven_-_nara_-_550384Beringia is the now-lost land between Alaska and Russia that was, during the last ice age, a vast grassland. It is believed that humans lived here for thousands of years, hunting mammoths, woolly rhinos, bison, and equines. The probably fished as well, just like modern humans in the area.

It was a land of frigid abundance, of herds of giant beasts that probably put the buffalo to shame.

Here is a nice podcast by Razib and Spencer on the lost paradises of Beringia, Sundaland, and Doggerland.

Old map of a mysterious, non-existent blob-land

Humans lived in Beringia for thousands of years before they made it into the rest of North America, because the rest of the continent was blocked off, then, by a giant impenetrable ice sheet. This period is therefore referred to as the “Beringia pause” because humans “paused” here during their migration from Siberia to the Americas, but this name obscures the lives and purposes of the people who lived here. They weren’t consciously trying to get to North America and pausing for thousands of years because their way was blocked; they were happily living their lives in a land of abundant resources. We could equally say that Europeans “paused” in Europe for thousands of years before some of them migrated to the Americas, or that anyone on Earth has “paused” in the place they are now.

DNA of the Eskimo/Inuit and related peoples, from Haak et al

According to an article published recently in Nature, The Population History of Siberia since the Pleistocine, by Martin Sikora et 53 other people, these folks in Beringia have their own interesting and complex population history, full of migration and back-migration, conquering, splitting, and joining:

Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of ‘Ancient North Siberians’ who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to ‘Ancient Palaeo-Siberians’ who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name ‘Neo-Siberians’, and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas.

There is a lot of interesting material in this paper (and some nice maps and graphs), but I’m too tired to summarize it all and not lose accuracy, so I encourage you to read it yourself; perhaps the most interesting part involves migration from Alaska to Siberia, across the now-Bering Strait, of people like the Ekven (are these the same as the awkwardly named Evens?)

The polar world is a fascinating circle.

“Argumentum ab Papuan”

I propose the naming of a fallacy: argumentum ab Papuan.

Argumentum ab Papuan happens when someone tries to construct an argument about human nature based off a handful (or fewer) ethnographic accounts of tiny, obscure tribes (or chimps).

These arguments are questionable because:

  1. Ethnographers sometimes get things wrong. Sometimes they lie; sometimes people lie to them; sometimes mistakes are made.

For example, ethnographers have been fond of calling the Bushmen of the Kalahari the “harmless people” while castigating westerners for their high rates of violence, but if you actually count up the dead bodies, the Bushmen have much higher murder rates than Westerners.

Margaret Mead famously wrote a book titled “Coming of Age in Samoa” about the free-love sex lives of Samoan teens that turned out to be, apparently, a bunch of lies told to her by giggling 14 year olds.

I recently saw someone misinterpret something in the ethnographic literature as implying that the men in a particular tribe carried on life-long, mutually enjoyable homosexual relationships with each other, when actually they occasionally kidnapped boys from neighboring tribes and raped them.

2. Sometimes people do stupid things. Overall, on the grand scale of the arc of humanity, most of the stupid ideas get weeded out and good ideas stick around. Usually. But on the short term, people make plenty of mistakes.

We can look at our own society and identify plenty of stupid things people do that we would never take as indicative of society as a whole, much less humanity as a whole. Small, isolated tribes are not immune to bad ideas, either. When we’re talking about a group whose entire membership is smaller than your average furry convention, (eg, Midwest FurFest drew nearly 11,000 people last year, while the Hadza number only 1,300,) we should be cautious about over-extrapolating from a few reported behaviors or activities. We might just be looking at the opinions of a handful of people whom the rest of the tribe disagrees with, or a practice that is soon abandoned because people decided it was a bad idea. The Papuans with the pedophile rape gangs, for example, actually abandoned the practice because they decided it was really kind of mean.

3. Different strokes for different folks: what works great in one place or culture may not be useful at all in another.

The Inuit/Eskimo build houses out of snow; this does not mean you should build houses out of snow. Bonobos do their bonobo thing; you are not a bonobo and bonobo social hierarchies are not your social hierarchies. The meaning of an act may change over time, too. Headcoverings were more common back when people washed their hair less often and lice were a problem; with the adoption of modern hygiene, headcoverings have taken on symbolic meanings related to modesty and religion. Social norms that were useful for people who had no technological means of long-distance communication may not be useful for people who have telephones, and vice versa.

And I don’t know about you, but there are many cultures in this world that I am not willing to live in and do not have any desire to imitate. No running water? No penicillin? No epidurals? No refrigeration? No general norm against raping women and children? Forgive me if I am not eager to imitate this culture.

This is not to say that we cannot learn anything from each other. I absolutely believe there is a lot we can learn by studying other groups of people, whether small or large, stone age or space age. But we should be careful about making overly broad arguments from too little data or missing the big picture because we were overly focused on small exceptions. There will always be some weird group of people that does some weird thing; without some broader context, this doesn’t necessarily say anything about the rest of us.


I just want to highlight this graph I came across yesterday while trying to research archaic introgression in the Igbo:


From Whole-genome sequence analysis of a Pan African set of samples reveals archaic gene flow from an extinct basal population of modern humans into sub-Saharan populations, by Lorente-Galdos et al.

There are three versions of this graph in the paper (check the supplemental materials for two of them), all showing about the same thing. It is supposed to be a graph of population size at different times in the past, and the most incredible thing is that for the past 100,000 years or so, the most numerically dominant populations in Africa were the Baka Pygmies, followed by various Bushmen (San) groups. The authors write:

To unravel the ancient demographic history of the African populations that are present in our data set, we used the Pairwise Sequentially Markovian Coalescent (PSMC) model that analyzes the dynamics of the effective population size over time [60]. We included at least one representative of each of the 15 African populations and two Eurasian samples in the analysis (Additional file 1: Figure S7.1) and considered both the classical mutation rate of 2.5 × 10−8 [61] and the 1.2 × 10−8 mutations per bp per generation reported in other analyses [6263]. The demographic trajectories of the sub-Saharan agriculturalist populations are very similar to each other; and only South African Bantu and Toubou individuals differ partly from the rest of sub-Saharan farmer samples; however, their considerable levels of admixture with other North African or hunter-gatherer populations (Fig. 2b) might explain this trend. Therefore, in order to ease visualization, we plotted a Yoruba individual (Yoruba_HGDP00936) and two Ju|‘hoansi individuals as representatives of the sub-Saharan agriculturalist and Khoisan populations, respectively (Fig. 3 and Additional file 1: Figure S7.2 considering a mutation rate of 1.2 × 10−8).

The authors note that the apparent large size of the pygmy groups could have been due to groups splitting and merging and thus getting more DNA variety than they would normally. It’s all very speculative. But still, the Baka Pygmies could have been the absolutely dominant group over central Africa for centuries.

What happened?


Book Club: Chinua Achebe’s Things Fall Apart, pt 3/3


Chinua Achebe, Author and Nobel Prize winner

Welcome back to our discussion of Chinua Achebe’s Things Fall Apart. Today I wanted to take a closer look at some of the aspects of traditional Igbo society mentioned in the book.

If you are a regular reader of this blog, you know by now that just as early modern humans (Homo sapiens) mated with Neanderthals and Denisovans somewhere over in Eurasia, some sapiens mated with archaic humans in Africa.

Unfortunately, the state of knowledge about African genomes and especially archaic African genomes is very primitive. Not only does ancient DNA not preserve terribly well in many parts of Africa, but the continent is also rather poor and so people there don’t send their spit to 23 and Me very often to get DNA tested. Thus, sadly, I do not have archaic DNA percents for the Igbo.

“Approximate Bayesian computation estimates for the introgressing population across four African populations (Yoruba from Ibadan (YRI), Esan in Nigeria [ESN], Gambian in Western Divisions in the Gambia [GWD], and Mende in Sierra Leone [MSL]),” from Recovering Signals of Ghost Archaic Introgression in African Populations
However, we do have data for their neighbors, the Yoruba, Esan, Mende, and Gambians.

Keep in mind that so far, Eurasians measure about 1-4% Neanderthal and Melanesians about 6% Denisovan, so 10% Ghost in west Africans is a pretty big deal (if you’re into archaic DNA.) The authors of the study estimate that the admixture occurred about 50,000 years ago, which is coincidentally about the same time as the admixture in non-Africans–suggesting that whatever triggered the Out of Africa migration may have also simultaneously triggered an Into Africa migration. 

If you’re not familiar with some of these groups (I only know a little about the Yoruba,) the Esan, Mende, Gambians, and Yoruba are all speakers of languages from the Niger-Congo family (of which the Bantu languages are a sub-set.) The Niger-Congo family is one of the world’s largest, with 1,540 languages and 700 million speakers. It spread within the past 3,000 years from a homeland somewhere in west Africa (possibly Nigeria) to dominate sub-Saharan Africa. As far as I can tell, the Igbo are quite similar genetically to the Yoruba, and the admixture event happened tens of thousands of years before these groups spread and split, so there’s a good chance that the Igbo have similarly high levels of ghost-pop admixture.

Interestingly, a population related to the Bushmen and Pygmies used to dominate central and southern Africa, before the Bantu expansion. While the Bantu expansion and the admixture event are separated by a good 40 or 50 thousand years, this still suggests the possibility of human hybrid vigor.

Edit: A new paper just came out! Whole-genome sequence analysis of a Pan African set of samples reveals archaic gene flow from an extinct basal population of modern humans into sub-Saharan populations:

Here, we examine 15 African populations covering all major continental linguistic groups, ecosystems, and lifestyles within Africa through analysis of whole-genome sequence data of 21 individuals sequenced at deep coverage. We observe a remarkable correlation among genetic diversity and geographic distance, with the hunter-gatherer groups being more genetically differentiated and having larger effective population sizes throughout most modern-human history. Admixture signals are found between neighbor populations from both hunter-gatherer and agriculturalists groups, whereas North African individuals are closely related to Eurasian populations. Regarding archaic gene flow, we test six complex demographic models that consider recent admixture as well as archaic introgression. We identify the fingerprint of an archaic introgression event in the sub-Saharan populations included in the models (~ 4.0% in Khoisan, ~ 4.3% in Mbuti Pygmies, and ~ 5.8% in Mandenka) from an early divergent and currently extinct ghost modern human lineage.

So the ghost population that shows up in the Pygmies the same ghost population as shows up in the Mende? Looks like it.

There’s a lot of interesting stuff in this paper, but I’d just like to highlight this one graph:


I don’t really understand how they compute these things, much less if this is accurate (though their present estimate for the size of the Han looks pretty good,) but assuming it is, we can say a few things: One, before 100,000 years ago, all of the groups–except the Laal of Chad–tracked closely together in size because they were one group. Most of the groups then got smaller simply because they split up. But there seems to have been some kind of really big population bottleneck a bit over a million years ago.

The other really interesting thing is the absolute Pygmy dominance of the mid-10,000-100,000 year range. The authors note:

It is noteworthy that we observed by PSMC a sudden Ne increase in Baka Pygmy around 30 kya. A similar increase was observed in another study that analyzed several Baka and Biaka samples [25]. In addition, this individual presents the highest average genome-wide heterozygosity compared to the rest of samples (Fig. 1b). Nevertheless, such abrupt Ne increase can be attributed to either a population expansion or episodes of separation and admixture [60]. Further analyses at population level are needed to distinguish between these two scenarios.

Until we get more information on the possible Pygmy-cide, let’s get back to Things Fall Apart, for the Igbo of 1890 aren’t their ancestors of 50,000 BC nor the conquerors of central Africa. Here’s an interesting page with information about some of the rituals Achebe wrote about, like the Feast of the New Yams and the Egwugwu ceremony:

 The egwugwu ceremony takes place in order to dispute the guilty side of a crime taken place, similar to our court trials… Nine egwugwu represented a village of the clan, their leader known as Evil Forest; exit the huts with their masks on.

Short page; fast read.

The egwugwu ceremony I found particularly interesting. Of course everyone knows the guys in masks are just guys in masks (well, I assume everyone knows that. It seems obvious,) yet in taking on the masks, they adopt a kind of veil of anonymity. In real life, they are people, with all of the biases of ordinary people; under the mask, they take on the identity of a spirit, free from the biases of ordinary people. It is similar to the official garb worn by judges in other countries, which often look quite silly (wigs on English barristers, for example,) but effectively demarcate a line between normal life and official pronouncements. By putting on the costume of the office, the judge becomes more than an individual.

I have long been fascinated by masks, masquerades, and the power of anonymity. Many famous writers, from Benjamin Franklin to Samuel Clemens, published under pseudonyms. The mask implies falseness–on Halloween, we dress up as things that we are not–but it also allows honesty by freeing us from the threat of retribution.

It is interesting that a small, tightly-knit society where everyone knows everyone and social relations are of paramount importance, like the Igbo, developed a norm of anonymizing judges in order to remove judicial decisions from normal social relations and obligations (as much as possible, anyway). Since most Igbo villages did not have kings or other aristocrats to dictate laws, rule was conducted by notable community members who had effectively purchased or earned noble titles. These nobles got to wear the masks and costumes of the egwgwu.

Ok, so it’s getting late and I need to wrap this up. This moment comes in every post.

I know I haven’t said much about the book itself. The plot, narrative, pacing, structure, writing style, etc. To be honest, that’s because I didn’t enjoy it very much. It was interesting for its content, along with a sense of “I’ve been trying to tell people this and I could have saved myself a lot of time by just pointing them to the book. And if this is a book taught in schools (we didn’t read it in my highschool, but I have heard that many people did,) then why aren’t people more aware of the contents?

What was tribal life like before the Europeans got there? Well, women got beaten a lot. Children were murdered to avenge tribal conflicts. Infant mortality was high. In other words, many things were pretty unpleasant.

And yet, interestingly, much of what we think was unpleasant about them was, in its own way, keeping the peace. As Will (Evolving Moloch) quotes from The Social Structure of Right and Wrong on Twitter:

“Much of the conduct described by anthropologists as conflict management, social control, or even law in tribal and other traditional societies is regarded as crime in modern [nation state] societies.” This is especially clear in the case of violent modes of redress such as assassination, feuding, fighting, maiming, and beating, but it also applies to the confiscation and destruction of property and to other forms of deprivation and humiliation. Such actions typically express a grievance by one person or group against another.

See, for example, when the village burned down Okonkwo’s house for accidentally killing a villager, when they burned down the church for “killing” a deity, or when they took a little girl and killed a little boy in revenge for someone in another village killing one of their women. To the villagers, these were all legal punishments, and the logic of burning down a person’s house if they have killed someone is rather similar to the logic of charging someone a fine for committing manslaughter. Even though Okonkwo didn’t mean to kill anyone, he should have been more careful with his gun, which he knew was dangerous and could kill someone.

Unlike penalties imposed by the state, however, private executions of this kind often result in revenge or even a feud—Moreover, the person killed in retaliation may not be himself or herself a killer, for in these societies violent conflicts between nonkin are virtually always handled in a framework of collective responsibility–or more precisely, collective liability–whereby all members of a social category (such as a family or lineage) are held accountable for the conduct of their fellows.

And, of course, penalties so meted out can be incredibly violent, arbitrary, and selfish, but ignoring that, there’s clearly a conflict when traditional, tribal ways of dealing with problems clash with state-based ways of dealing with problems. Even if everyone eventually agrees that the state-based system is more effective (and I don’t expect everyone to agree) the transition is liable to be difficult for some people, especially if, as in the book, they are punished by the state for enforcing punishments prescribed by their own traditional laws. The state is effectively punishing them for punishing law-breakers, creating what must seem to them a state of anarcho-tyranny.

As for polygamy, Achebe seems to gloss over some of its downsides. From Christakis’s Blueprint: The Origins of a Good Society (h/t Rob Henderson), we have:

Co-wife conflict is ubiquitous in polygynous households… Because the Turkana often choose wives from different families in order to broaden their safety net, they typically do not practice sororal [sister-wives] polygyny… When co-wives are relatives, they can more easily share a household and cooperate… But while sororal polygyny is especially common in cultures in the Americas, general polygyny tends to be the usual pattern in Africa. An examination of ethnographic data from 69 nonsororal polygynous cultures fails to turn up a single society where co-wife relations could be described as harmonious. Detailed ethnographic studies highlight the stresses and fears present in polygynous families, including, for example, wives’ concern that other wives might try to poison their children so that their own children might inherit land or property.

Anyway, let’s wrap this up with a little article on human pacification:

There is a well-entrenched schism on the frequency (how often), intensity (deaths per 100,000/year), and evolutionary significance of warfare among hunter-gatherers compared with large-scale societies. To simplify, Rousseauians argue that warfare among prehistoric and contemporary hunter-gatherers was nearly absent and, if present, was a late cultural invention. In contrast, so-called Hobbesians argue that violence was relatively common but variable among hunter-gatherers. … Furthermore, Hobbesians with empirical data have already established that the frequency and intensity of hunter-gatherer warfare is greater compared with large-scale societies even though horticultural societies engage in warfare more intensively than hunter-gatherers. In the end I argue that although war is a primitive trait we may share with chimpanzees and/or our last common ancestor, the ability of hunter-gatherer bands to live peaceably with their neighbors, even though war may occur, is a derived trait that fundamentally distinguishes us socially and politically from chimpanzee societies. It is a point often lost in these debates.

I think we should read Legal Systems Very Different from Ours for our next book. Any other ideas?

Book Club: Chinua Achebe’s Things Fall Apart, pt 2


Chinua Achebe, Author and Nobel Prize winner

Welcome back to our discussion of Chinua Achebe’s Things Fall Apart. Today I thought it would be interesting to look at the history of the Igbo (aka Ibo) people, past and present.

The modern Igbo are one of the world’s larger ethnic groups, numbering around 34 million people, most of whom live in south east/central Nigeria. About 2 million Igbo live abroad, most of them in Britain (which, Chinua recounts, colonized Nigeria.) The Igbo diaspora is well-known for its intelligence, with Igbo students outscoring even Chinese students in the UK:

Although the Chinese and Indians are still very conspicuously above even the best African nationalities, their superiority disappears when the Nigerian and other groups are broken down even further according to their different tribal ethnicities. Groups like the famous Igbo tribe, which has contributed much genetically to the African American blacks, are well known to be high academic achievers within Nigeria. In fact, their performance seems to be at least as high as the “model minority” Chinese and Indians in the UK, as seen when some recent African immigrants are divided into languages spoken at home (which also indicates that these are not multigenerational descendants but children of recent immigrants).

Africans speaking Luganda and Krio did better than the Chinese students in 2011. The igbo were even more impressive given their much bigger numbers (and their consistently high performance over the years, gaining a 100 percent pass rate in 2009!). The superior Igbo achievement on GCSEs is not new and has been noted in studies that came before the recent media discovery of African performance. A 2007 report on “case study” model schools in Lambeth also included a rare disclosure of specified Igbo performance (recorded as Ibo in the table below) and it confirms that Igbos have been performing exceptionally well for a long time (5 + A*-C GCSEs); in fact, it is difficult to find a time when they ever performed below British whites.

Of course, Igbo immigrants to the UK are probably smarter than folks who didn’t figure out how to immigrate to the UK, but Peter Frost argues that even the ones who stayed at home are also pretty smart, via a collection of quotes:

All over Nigeria, Ibos filled urban jobs at every level far out of proportion to their numbers, as laborers and domestic servants, as bureaucrats, corporate managers, and technicians. Two-thirds of the senior jobs in the Nigerian Railway Corporation were held by Ibos. Three-quarters of Nigeria’s diplomats came from the Eastern Region. So did almost half of the 4,500 students graduating from Nigerian universities in 1966. The Ibos became known as the “Jews of Africa,” despised—and envied—for their achievements and acquisitiveness. (Baker, 1980)

The Ibos are the wandering Jews of West Africa — gifted, aggressive, Westernized; at best envied and resented, but mostly despised by the mass of their neighbors in the Federation.(Kissinger, 1969)

So what makes the Igbo so smart? Frost attributes their high IQ to the selective effects of an economy based on trade in which the Igbo were middlemen to the other peoples (mostly Yoruba and Fulani) around them, along with an excellent metalworking tradition:

Archaeological sites in the Niger Delta show that advanced economic development began much earlier there than elsewhere in West Africa. This is seen in early use of metallurgy. At one metallurgical complex, dated to 765 BC, iron ore was smelted in furnaces measuring a meter wide. The molten slag was drained through conduits to pits, where it formed blocks weighing up to 43-47 kg. …

This production seems to have been in excess of local needs and therefore driven by trade with other peoples …

This metallurgy is unusual not only in its early date for West Africa but also in its subsequent development, which reached a high level of sophistication despite a lack of borrowing from metallurgical traditions in the Middle East and Europe.

Here is a fun little video on Igbo bronzes (I recommend watching on double speed and pausing occasionally to appreciate the work quality):

So between the bronze, the river, and long-distance trade, the Igbo became the local market dominant minorities–and like most MDMs, with the arrival of democracy came genocide.

Nigeria achieved independence in 1960 and became a Republic in 1963. Periodic military coups and conflict kept disturbing the peace:

From June through October 1966, pogroms in the North killed an estimated 80,000 to 100,000 Igbo, half of them children, and caused more than a million to two million to flee to the Eastern Region.[76] 29 September 1966, was considered the worst day; because of massacres, it was called ‘Black Thursday’.[77][78]

Ethnomusicologist Charles Keil, who was visiting Nigeria in 1966, recounted:

The pogroms I witnessed in Makurdi, Nigeria (late Sept. 1966) were foreshadowed by months of intensive anti-Ibo and anti-Eastern conversations among Tiv, Idoma, Hausa and other Northerners resident in Makurdi, and, fitting a pattern replicated in city after city, the massacres were led by the Nigerian army. Before, during and after the slaughter, Col. Gowon could be heard over the radio issuing ‘guarantees of safety’ to all Easterners, all citizens of Nigeria, but the intent of the soldiers, the only power that counts in Nigeria now or then, was painfully clear. After counting the disemboweled bodies along the Makurdi road I was escorted back to the city by soldiers who apologised for the stench and explained politely that they were doing me and the world a great favor by eliminating Igbos.

… until the Igbos decided they’d had enough and declared themselves an independent country, Biafra, triggering a civil war. The Nigerian and British governments blockaded Biafra, resulting in mass starvation that left nearly 2 million dead.

Why the British government thought it was important to use money to starve children, I don’t know.

(Hint: the answer is oil.)

During the war, Britain covertly supplied Nigeria with weapons and military intelligence and may have also helped it to hire mercenaries.[102] After the decision was made to back Nigeria, the BBC oriented its reporting to favour this side.[103] Supplies provided to the Federal Military Government included two vessels and 60 vehicles.[104]


(Richard Nixon, always the voice of morality, was against the blockade.)

Chinua Achebe published Things Fall Apart in 1959, the year before independence–so he was awfully prescient.

As news got out about the genocide, people began demanding that food be airlifted into Biafra, but there were some problems getting the food off the ground:

Just “enemy propaganda” of little girls starving to death

Secretary General of the United Nations, U Thant, refused to support the airlift.[5] The position of the Organization of African Unity was to not intervene in conflicts its members’ deemed internal and to support the nation-state boundaries instituted during the colonial era.[6] The ruling Labour Party of the United Kingdom, which together with the USSR was supplying arms to the Nigerian military,[7]dismissed reports of famine as “enemy propaganda”.[8] Mark Curtis writes that the UK also reportedly provided military assistance on the ‘neutralisation of the rebel airstrips’, with the understanding that their destruction would put them out of use for daylight humanitarian relief flights.[9]

Soon Joint Church Aid, a combination of Protestant, Catholic, Jewish, and other NG organizations, chartered airplanes and began running the Nigerian blockade (three relief workers were killed when their plane was shot down.) The Biafra Airlift is second in scope only to the Berlin Airlift in non-combat airlifts.

Since the end of the war, the state of the Igbo people has steadily improved (the presence of oil in the area is finally benefiting them.)

Modern Nigeria has about 200 million people with a fertility rate around 5.5 children per woman (I don’t have data specifically about the Igbo) and a per capita GDP around $2,000, which is high for the area.

It’s getting late, so I’d like to end with some modern Igbo music, a reminder that the people we read about in anthropology books (or literature) never stay in anthropology books:

Out of Africa revisited? pt 2

nature-siberian-neanderthals-17.02.16-v2The out-of-Africa theory basically says that humans evolved in Africa, then spread in several pulses across the rest of the planet. The first hominin to leave Africa–as far as we know–was Erectus, followed by the Neanderthals/Denisovans, and finally Sapiens. Where exactly smaller, less well-known hominins like Homo Floresiensis fit into the picture we don’t know, yet.)

One of the incredible things about human evolution is just how many other human species we used to co-exist with. We shared this earth with at least 8 other species of human, met and mated with at least 4 of them. Before us came a proliferation of australopithecines.

Today, there is only us. This stunning diversity of upright apes has been winnowed to a single line. Species that had survived for thousands if not millions of years disappeared, either because they died out or were wiped out. We, sapiens, are the last ones standing.

Humans met Neanderthals. We interbred, briefly. Then the Neanderthals died out. Humans met Denisovans. We interbred, briefly. Then the Denisovans disappeared. Humans met so-called “Ghost populations” in west and southern Africa and interbred. The ghosts then disappeared. It’s all very mysterious how every other species of hominin and australopithecine seems to have died out immediately after we sapiens arrived in the area.

This implies, then, that sapiens didn’t live in these areas during the thousands or so years before we wiped out the locals (though some small exceptions may exist.)

So where did we live?

The West African Ghost Population contributed a big chunk of DNA to modern humans a mere 50,000 years ago–around the same time as sapiens were mating with Neanderthals. This seems to have been a much more significant encounter than the one with Neanderthals–perhaps many of these “ghosts” joined the sapiens who moved into their area.

So west Africa was likely not inhabited by modern humans before 50,000 years ago.

Homo naledi is too small to have co-existed with us, effectively ruling out their part of South Africa during that period, and the Pygmies probably interbred with their mystery hominin around 35,000 years ago, so that rules out the Congolese forest area.

The Neanderthal ancestry is in pretty much everyone not in Africa, (and a little in Africa due to recent back-migration) which is pretty strong support for the out-of-Africa theory. The most parsimonious explanation is that a single population split, and half of that population, as it entered Eurasia, encountered Neanderthals, while the other half traveled deeper into Africa and encountered African hominins.

East Africa/the horn of Africa region remains, therefore, the most logical spot to locate Homo sapiens immediately before this splitting phase, but I wouldn’t rule out the Middle East.

On the other hand, Homo sapiens’s ancestor, Homo heidelbergensis, lived in Africa, Europe, and the Middle East for thousands, possibly a million years (depending on how we classify the similar bones of Homo antecessor, who lived near Norfolk, England, about 950,000 years ago. Homo heidelbergensis’s (probable) ancestor, Homo erectus, lived in Africa, Europe, and Asia for over a million years.

Here’s where it gets complicated, because while species like the little hobbits from Flores are clearly different from other varieties of Homo, there are no clear dividing lines between folks like erectus, heidelbergensis, and ergastor. We have a bunch of bones, a few nice skulls, scattered across continents and centuries, from which we try to derive a vague sense of whether this population and that population were similar enough to consider them a single species. Quoting Wikipedia:

Although “Homo ergaster” has gained some acceptance as a valid taxon since its proposal in 1975, ergaster and erectus since the 1980s have increasingly come to be seen as separate (that is, African or Asian) populations of the larger species H. erectus. … The question was described as “famously unresolved” as of 2003.[10] Sura et al (2007) concluded that Homo erectus “was a likely source of multiple events of gene flow to the Eurasian continent”.[11]

The discoveries of the Dmanisi skulls in the South Caucasus since 2005 have re-opened this question. Their great morphological diversity suggests that the variability of Eurasian H. erectus already includes the African fossils dubbed H. ergaster. The discovery of Dmanisi skull 5 in 2013, dated to 1.8 million years ago, now dates evidence of H. erectus in Eurasia as of virtually the same age as evidence for H. ergaster in Africa, so that it is unclear if the speciation of H. erectus/ergaster from H. habilis took place in Africa or Asia.[12] This has reinforced the trend of considering H. ergaster as synonymous with H. erectus, a species which would have evolved just after 2 million years ago, either in Africa or West Asia, and later dispersed throughout Africa and Eurasia.[13][14]

Homo habilis, by contrast, is (so far) only found in east Africa.

What does it mean to evolve in a place? Habilis, as far as we know, actually did evolve in Africa. It didn’t leave Africa; neither did the australopithecines (unless one of those little hobbity folks out in the Philippines turn out to be australopiths, but that would be very remarkable). But after that, “humans” spread from Africa to Europe and Asia with remarkable speed. They lived in England almost a million years ago. And within this range, we seem to have become repeatedly isolated, speciated, and then met back up again when the weather improved.

Personally, I wouldn’t say that the out of Africa theory is wrong. It is still the most parsimonious explanation of human evolutionary history. However, I would say that it simplifies a huge chunk of our history, since for most of our time on this earth, our range has been quite a bit larger than Africa.

Cracks in the Out of Africa Theory?

The most exciting finding of the past two decades in biological anthropology has been, without a doubt, evidence for interbreeding between Homo sapiens, Neanderthals, Denisovans, etc. and the sheer multiplicity of new hominin species being uncovered.

Exactly where the lines between species lie is a bit of a matter of semantic debate–where exactly did our ancestors end and Homo sapiens begin? Should we classify Neanderthals and Sapiens as one species if we interbred? etc–but if we accept the current classifications as decent approximations, we have:

Source: Wikipedia

Sorry, I realized it would be much more efficient if I just grabbed the family tree off Wikipedia instead of copying it over bit by bit. The top part of the tree got cut off, so I’ll note that Homini (6.3 million years ago) includes us + chimps, while Hominina (5.7 million years ago) has no chimps, but includes australopithecines. Gorillas are way back in Homininae, with an e. Homo, our genus, includes all of the “human” species, but usually doesn’t include australopithecines.

There is further debate on exactly who descended from whom. We’re finding new fossils all the time, which is quite exciting, but our current record is not nearly as complete as we’d like it to be. So sometimes branches get moved around or re-categorized as more data comes to light.

The most recent notable additions to our genus are the Denisovans, Homo floresiensis, Homo luzonensis, Homo Naledi, Homo doesn’t have a name yet, and more Denisovans.

You have probably heard of the “hobbit,” Homo floresiensis. The remains we have uncovered of this diminutive hominin are remarkably good, including a skull in great condition (despite some damage caused after excavation.) They lived on the island of Flores from about 200,000 to 50,000 years ago (though their arrival may get pushed back considerably because there are stone tools on Flores that are much older–700,000 years old–we just don’t know yet who used them.)

The hobbits are remarkable in multiple ways. First, they lived in an area that was not connected to the mainland by any landbridges–that is, they had to swim, boat, or otherwise be carried to their island. I am skeptical of the idea of anyone surviving a tsunami as a means of populating an island, but they arrived in an era when, as far as we know, humans had yet to build boats. So perhaps their ancestors were among the first humans to build boats, and we just haven’t found the remains of their crafts (wood being a material that degenerates very quickly.)

Second, the Hobbits are most likely descended from Homo erectus, who lived nearby on mainland Indonesia (at the time, connected to the rest of Asia via a landbridge), but are morphologically very different. They are tiny–shorter than pygmies, Homo erectus, or even australopithecines.

There is much debate about whether they are descended directly from erectus, or part of a sister-clade to erectus that descended from a common ancestor. It was previously believed that erectus was the first hominin to leave Africa, but if Floresiensis is not descended from erectus, Flores could be the first.

Now a similarly diminutive hominin has turned up in the Philippines, also past a significant water barrier that would require some effort to cross. It has been dubbed Homo luzonensis. Not much is known, yet, about luzonensis, (we haven’t found as many of its bones), but what we do know is tantalizing:

It was soon apparent to Détroit that the remains featured a puzzling mosaic of traits both modern and ancient. “Each of the features [of Homo luzonensis] corresponds to some hominin or another,” he says. “But the combination makes for something really unique. There’s no known species with this same suite of features.”

They’re small, possibly even smaller than the Hobbits. Their feet resemble australopithecines, but australopithecines supposedly died out a couple million years before Luzonensis arrived on the scene. And their teeth were “remarkably uniform,” which probably sounds boring to anyone who isn’t a dentist, but provides strong evidence of them being a different species.

Two island dwelling species in the same area supports the idea that their ancestors either developed boats or were remarkably skilled at surviving tsunamis, and that southeast Asia was a remarkable hotspot of hominin diversity.

And then there are the Denisovans!

Denisovans are mysterious because we have so few of their bones–a chunk of skull was recently uncovered, but we have no jaws, no faces, no ribs, etc–so we don’t have a good idea of what they looked like. What we do have are Denisovan DNA (extracted from those fragments of skeletons) and traces of Denisovan DNA in modern humans.

Oddly, those Denisovan bones turned up in Siberia (a good place for preserving old bones, but not such a great place for humans adapted to warm climates) while the humans with Denisovan DNA live in modern Papua New Guinea and nearby areas.

The obvious answer to this puzzle is that both the Denisovans had a much broader range than one cave in Siberia and the ancestors of modern folks from PNG used to live in different areas than they do now.

A more detailed analysis of PNG DNA was recently released, which reveals three separate, significant groups of Denisovans who interbred with sapiens:

… modern Papuans carry hundreds of gene variants from two deeply divergent Denisovan lineages that separated [from each other] over 350 thousand years ago. Spatial and temporal structure among these lineages suggest that introgression from one of these Denisovan groups predominantly took place east of the Wallace line and continued until near the end of the Pleistocene. A third Denisovan lineage occurs in modern East Asians. This regional mosaic suggests considerable complexity in archaic contact, with modern humans interbreeding with multiple Denisovan groups that were geographically isolated from each other over deep evolutionary time.

The Wallace line is a place that’s too deep for a landbridge, and thus the area to the east was an island even during the Ice Age. In other words, it looks like Denisovans could use boats. (Or survive tsunamis, pfft.)

Next, we sought to retrieve dates of divergence between D1, D2, and the Altai Denisovan genome … to encompass two deeply divergent Denisovan-related components, our best fitting model indicates that D1 and D2 split from the Altai Denisovan approximately 283 kya … respectively (Figure 4B). While clearly branching off the Denisovan line, D2 diverged so closely to the Neanderthal-Denisovan split that it is perhaps better considered as a third sister group… For context, even the youngest of these divergence times is similar to the evolutionary age of anatomically modern humans … Our model implies substantial reproductive separation of multiple Denisovan-like populations over a period of hundreds of thousands of years. … 

The genetic diversity within the Denisovan clade is consistent with their deep divergence and separation into at least three geographically disparate branches, with one contributing an introgression signal in Oceania and to a lesser extent across Asia (D2), another apparently restricted to New Guinea and nearby islands (D1), and a third in East Asia and Siberia (D0). This suggests that Denisovans were capable of crossing major geographical barriers, including the persistent sea lanes that separated Asia from Wallacea and New Guinea. They therefore spanned an incredible diversity of environments, from temperate continental steppes to tropical equatorial islands.

(We will probably reclassify some of the older fossils from Asia as Denisovans once we figure out what they looked like.)

Then we have Homo naledi, from South Africa. Naledi lived around 250,000 years ago, about the same time as Homo sapiens were differentiating from their ancestors. We have a wonderful array of Homo naledi fossils, preserved in the bottom of a cave pit. If they were placed here intentionally, this was pretty advanced behavior, though I wonder if perhaps they just got lost in the cave from time to time and then died in the pit.

At about 5 ft tall, (male height) naledi was short, but not nearly as short as Floresiensis, and taller than some groups of sapiens. Its skull was significantly smaller than a modern skull, however, and I find it odd that, out of the thousands of bones and fragments discovered, we have not yet recovered much of the front of their faces. Perhaps their faces were shattered when they fell into the cave?

Naledi, like Floresiensis and Luzonensis, shares some more modern traits with other members of the homo genus, and some traits with the older australopithecines. Unlike them, we have yet to uncover evidence that Naledi used tools.

The we have a couple of unnamed hominins

These so-called “ghost populations” are known entirely from their presence in the DNA of modern humans. We don’t have any fossils from them, either because they lived in areas where the weather didn’t favor preservation, or the modern political climate makes searching for fossils difficult.

The pygmies and Bushmen derive about 2% of their DNA from an archaic population or two that we estimate split off from the rest of us about 700,000 years ago. They met and mated with these other hominins around 35,000 years ago.

More interesting is another ghost population that shows up in the genomes of west African groups like the Mende. Now, the average non-African has about 1-4% Neanderthal DNA, and Melanesians have about 4-6% Denisovan, but some tribes in west Africa, such as the Yoruba, Mende, Gambians, and Esan, may derive about 10% of their DNA from an otherwise unknown ghost population that split off before the Neanderthals! (Razib’s very nice article summarizing the paper.)


Oh, jeeze, it’s three am, let me finish this in the next post…



Who were the Jomon?



The modern people of Japan are descended from two main groups–the Yayoi, rice farmers who arrived in the archipelago around 800 BC, and the Jomon, hunter-gatherers who arrived thousands of years before.

The oldest known skeletons in Japan are about 30,000 years old. The first 20,000 years of Japanese history are the Paleolithic; the Jomon period, marked by distinct pottery, begins around 14,000 BC.

Despite being hunter-gatherers, the Jomon reached a relatively high level of cultural sophistication (Wikipedia has a nice collection of Jomon art and buildings,) probably because Japan is a naturally lush and pleasant place to live. (The popular perception of hunter-gatherers as poor and constantly on the brink of death is due to the best land having been conquered by farmers over the past few thousand years and enormous population growth over the past hundred. Neither of these factors affected the Jomon at their peak.)

Who were the Jomon? Were they descended directly from the paleolithic peoples of Japan, or were they (relative) newcomers? And what happened to them when the Yayoi arrived? Did they inter-marry? Are the Ainu their modern descendants?

An interesting new paper posted on BioRxiv, Jomon genome sheds light on East Asian population history, examines the DNA of a 2,500 year old individual:

After the major Out-of-Africa dispersal of Homo sapiens around 60 kya, modern humans rapidly expanded across the vast landscapes of Eurasia[1]. Both fossil and ancient genomic evidence suggest that groups ancestrally related to present-day East Asians were present in eastern China by as early as 40 kya[2]. Two major routes for these dispersals have been proposed, either from the northern or southern parts of the Himalaya mountains[1,35].

So far the genetic studies have suggested a southern migration route, but archaeological evidence suggests a northern route or at least significant northern trade routes.

Note: the paper claims that the Jomon invented the world’s first pottery, but this appears to be incorrect; according to Wikipedia, the oldest known pottery is from China. However, the Jomon are very close.

To identify the origin of the Jomon people, we sequenced a 1.85-fold genomic coverage of a 2,500-years old Jomon individual (IK002) excavated from the central part of the Japanese archipelago[15]. Comparing the Jomon whole-genome sequence with ancient Southeast Asians, we previously reported genetic affinity between IK002 and the 8,000-years old Hòabìnhian hunter-gatherer[15]. This direct evidence on the link between the Jomon and Southeast Asians, thus, confirms the southern route origin of East Asians.

Ideally, it would be nice to have a bunch of much older samples, but is difficult to get older DNA from Japanese skeletons because Japan is generally warm and humid, which interferes with preservation. It’s really amazing that we can get what little old DNA we can.

I’m going to call IK002 “Ikari” from here on.

Ikari’s mother hails from mitochondrial haplogroup N9b1, which previous studies have established as common in ancient Jomon people. It’s quite rare in modern Japan, however–which is somewhat unusual, since invading armies usually like to turn the local women into war brides rather than wipe them out entirely. The mitochondrial DNA of Latin American people, for example, hails primarily from native women, while their Y chromosomes hail primarily from Spanish conquistadors.

“Principal component analysis (PCA) of ancient and present-day individuals from worldwide populations after the out-of-Africa expansion. Grey labels represent population codes showing coordinates for individuals. Coloured circles indicate ancient individuals.”

Then we get to the exciting part.

The authors use numerous methods to compare Ikari’s DNA to that of other people, ancient and modern. The graph at right shows Ikari (the red diamod) closest to the Kusunda, a modern day people living in Nepal! According to Wikipedia, there are only 164 Kusunda left, with only one surviving speaker of their native language, itself an isolate. (Though the Wikipedia page on the Kusunda language claims that 7 or 8 more speakers were recently discovered.)

The other shapes close to Ikari on this graph are are Sherpas and another iron-age individual from Tibet.

The Ainu are not shown on this graph, but Ikari is closely related to them, as well.

Second, when using a smaller number of SNPs (41,264 SNPs) including the present-day Ainu[34] from Hokkaido (Fig.S1), IK002 clusters with the Hokkaido Ainu (Fig.S4), supporting previous findings that they are direct descendants of the Jomon people[14,3441].

200px-Mongoloid_Australoid_Negrito_Asia_Distribution_of_Asian_peoples_Sinodont_Sundadont(I have written previously about the Ainu, who are, of course, still alive:

Taken together, all of the evidence is still kind of scanty, but points to the possibility of a Melanesian-derived group that spread across south Asia, made it into Tibet and the Andaman Islands, walked into Indonesia, and then split up, with one branch heading up the coast to Taiwan, Okinawa, Japan, and perhaps across the Bering Strait and down to Brazil, while another group headed out to Australia.

Later, the ancestors of today’s east Asians moved into the area, largely displacing or wiping out the original population, except in the hardest places to reach, like Tibet, the Andaman Islands, Papua New Guinea, the Amazon Rainforest, and Hokkaido–the fringe.)

That was quite speculative, but an actual genetic link between Tibetans (broadly speaking, peoples of the Tibetan plateau) and the modern Ainu is pretty exciting.

Of course, the Jomon did not die out entirely when the Yayoi arrived–about 10% of the modern Japanese genome resembles Ikari’s, along with 6% of the nearby Siberian Ulchi people’s.

By contrast, the Yayoi are more closely related to the modern Han Chinese.

Further analysis reveals more fascinating details about the ancient peopling of Asia and the Americas: Ikari’s ancestors likely split off from the other Asians before the Native Americans headed to Alaska, giving us a rough time estimate for the Jomon’s arrival–older than the 26,000 year old split between East Asians vs Siberians & Native Americans, but younger than a particular 40,000 year old group that split off in China, found in Tianyuan.

This indicates that the Jomon are most likely descended from the Japanese Paleolithic people, who arrived around 30,000 years ago and simply developed pottery a few thousand years later, rather than more recent migrants.

Ainu Man showing off his beard

People have long speculated about whether the Ainu are related to Caucasians (whites, Europeans, Westerners, whatever you want to call them,) due to their abundantly bushy beards. There is some West-Eurasian admixture in the ancestors of East Siberians and Native Americans that pre-dates the peopling of the New World, but this admixture is not found in Ikari; the Ainu likely did not get their beards from wandering European hunter-gatherers.

As the tooth studies suggested, however, the Jomon and Ainu are related to the Taiwanese Aborigines, like the Ami and Atayal. (However, the final portion of the paper is a little confusing, so I may have misinterpreted something. Hopefully the authors can clarify a bit in their final form.) It is otherwise a fine paper, and I encourage you to read it.

What Ethic Group is This?



23 and Me map of genetic relatives, rounded. 

An ethnic group is a set of people with a common ancestry, culture, and language. The Han Chinese, at a 1.3 billion strong, are an ethnic group; the Samaritans, of whom there are fewer than a thousand, are also an ethnic group. Ishi was, before his death, an ethnic group of one: the last surviving member of the Yahi people of California. 

We sit within nested sets of genetic relatives:

Family<clan<tribe<ethnic group<race<species<genus

(You are most likely part Homo neanderthalensis, because different species within the Homo genus have interbred multiple times.)

Interestingly, Wikipedia lists African American as an ethnicity on its list of ethnic groups page (as they should, because it is). 

Four or five hundred relatives, from parents and children to fifth cousins, are enough to begin to describe an ethnic group. It certainly looks, based on the map, like I hail from an ethnic group–yet neither Wikipedia nor 23 and Me recognize this group.

According to Wikipedia

Larger ethnic groups may be subdivided into smaller sub-groups known variously as tribes or clans, which over time may become separate ethnic groups themselves due to endogamy or physical isolation from the parent group. Conversely, formerly separate ethnicities can merge to form a pan-ethnicity, and may eventually merge into one single ethnicity. Whether through division or amalgamation, the formation of a separate ethnic identity is referred to as ethnogenesis.

Of course, no one wants to submit their DNA to 23 and Me and get the result “You’re a white person from America.” (Nor “You’re a black person from America.”) We know that. People take these tests to look at their deeper history. 

But focusing only on the past makes it easy to lose sight of the present. You aren’t your ancestors. The world didn’t halt in 1492. I’m no more “British” or “European” than I am “Yamnaya” or “Anatolian farmer.” 

History moves on. New ethnic groups form. The past tells us something about where we’ve been–but not where we’re headed.