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I do like to suggest that the genetic and archaeological record support the conjecture of Conan the Barbarian in terms of what our male ancestors thought was “good in life.” Basically, to conquer your enemies and seize their women, which is a distillation of a disputed quote from Genghis Khan. Conan may be fiction, but Genghis Khan is not. As it happens there is a fair amount of circumstantial evidence that the genetic legacy of Genghis Khan is enormous. Not only did Khan father many sons, but so did their sons, and so forth. Tens of millions of men around the world are direct paternal descendants of Genghis Khan and his family.
This is known. But now more is known, thanks to a new paper out of Genome Research, A recent bottleneck of Y chromosome diversity coincides with a global change in culture. The upside of this paper is that it uses whole genome sequence of Y chromosomes to generate phylogenetic inferences. This is important because the Y chromosome has very little genetic variation relative to much of the rest of the genome. The downside is that because techniques were utilized to perform whole genome sequencing of the Y, the sample size, at 299, is not as large as we’ve gotten used to for analyses of uniparental lineages. That will change in the future, as there are many thousands of whole genome sequences of the Y in databases around the world, though perhaps not enough computational power allocated by funding agencies to crunch through them in the fashion on display in the paper (they didn’t use the whole sequence for a lot of the analysis, but ~35,000 SNPs).
So what are the major findings of the paper? Using a Bayesian Skyline Plot (BSP) it is rather clear that 4-8 thousand years ago there was a sharp drop in male effective population sizes across many world populations. It is also clear that the female effective population did not experience the same drastic contraction. The supplements have individual figures, and many of the events of history and archaeology can be easily mapped onto these population size changes. For example, the later reduction of African population sizes probably is due to the later adoption of agriculture in that continent, and timed with the Bantu expansion. In the New World the data seem to show late and persistent reduction in effective population size. The Columbian Exchange and massive population contraction subsequent to that is probably being picked up by this result. 
Intriguingly there is a detection of a two events in the European data, where the sample size is relatively large. The first major drop seems to coincide with the arrival of the “First Farmers” (e.g., LBK culture) in Northern Europe. In the Middle East (orange) you see collapse, and then a rapid ascent very early. This comports well with the early history of agriculture here. But in the European samples there is a rapid ascent, and then a level off ~3,000 years ago or so. This could be the arrival of Indo-European cultures to Europe. If the sample sizes for other regions were as large and representative as Northern Europe such subtle details might also have emerged there with the BSP method (to be clear, I suspect the crash in effective size in Europe is due to haplogroup I, while the delayed expansion is due to R1a and R1b arriving a few thousand years later).
Also of interest are is the deep structure of the different clades. Those of you stepped in Y chromosomal haplogroups can extract more from the figure to the top left, but it shows relationship of the primary groups as well as their recent expansion. The affinity of the Q and R clades to me indicate that those who argue that these are somehow related to the “Ancestral North Eurasians” are correct. Similarly, the position of I and J in the same clade points to their common descent from ancient West Eurasian Pleistocene groups. The I lineage is most exclusively associated with European hunter-gatherers, while J is traditionally associated with groups of farmers expanding out of the Middle East in all directions (note that one branch of J is found in the Middle East, Central Asia, South Asia, and Europe). I agree with Dienekes that the branch of E that corresponds to the lineages which span Sub-Saharan Africa and Western Eurasia are a indicating a back migration to Africa, probably in the Pleistocene. I do wonder as well whether they have some association with the mysterious “Basal Eurasians.”
An important part of the paper that they emphasize is that ~50,000 years before the present there was a profusion of haplogroups associated with the ones which are today common across Eurasia, and Y chromosomal Ne was ~100. This seems to agree with the rapid expansion of non-Africans in the wake of the “Out of Africa” event, though the authors note they don’t have enough power to reject a model of a separate “Southern Route” migration, which might be detected with autosomal data. This is a good caution on the limitations of Y and mtDNA data; archaic admixture was rejected by these two loci because the non-African hominin lineages went extinct (mtDNA and Y have higher turnover rates than the recombining autosomal regions). 
Additionally there were some major lacunae in the sampling. For example, among the African populations it doesn’t seem like some of the hunter-gatherer groups, the Khoisan or eastern Pygmy, were included in the data set. The map also shows that Northeast Asia (China, Japan and Korea) and Oceania were not extensively sampled. But these are minor issues in the broader picture of the insights from the population coverage that they did have.
The most important implication of these sorts of results have to do with the nature of the change of human social organization and behavior over the course of the existence of modern humans. The authors of the above paper seem to understand this, as there is extensive focus on the topic within the paper:
An increase in male migration rate might reduce the male Ne but is unlikely to cause a brief drastic reduction in Ne as observed in our empirical data…However, in models with competition among demes, an increased level of variance in expected offspring number among demes can drastically decrease the N e (Whitlock and Barton 1997). The effect may be male-specific, for example, if competition is through a male-driven conquest. A historical example might be the Mongol expansions (Zerjal et al. 2003). Innovations in transportation technology (e.g., the invention of the wheel, horse and camel domestication, and open water sailing) might have contributed to this pattern. Likely, the effect we observe is due to a combination of culturally driven increased male variance in offspring number within demes and an increased male-specific variance among demes, perhaps enhanced by increased sex-biased migration patterns (Destro-Bisol et al. 2004; Skoglund et al. 2014) and male-specific cultural inheritance of fitness.
To restate what’s being said here:
1) During the Holocene we saw the rise of powerful patrilineages which engaged in winner-take-all of inter-group competition.
2) Within the “winning” patrilineages there may have been winner-take-all dynamics, or at least high reproductive variance
When it comes to farmers and nomads against each other I do think a model of inter-demic competition is pretty realistic. But when it comes to farmers and nomads against hunter-gatherers I don’t think one can term it competition. The latter in most circumstances would be quickly overwhelmed by the farmers and nomads; eliminated, excluded, or at least assimilated (there are exceptions in areas where the hunter-gatherer density was high and they were sedentary). And as concerns the complex societies of farmers and nomads, even within them the rise of inequality and stratification mean that subordinate or secondary males and their lineages were marginalized, leaving few descendants.
Men are on average 15-20 percent bigger than women. Men are also stronger than women. But the sexual dimorphism is far less than one can find among gorillas. This suggests that intra-sex competition among males was attenuated, or at least it was not in the physical domain. Though I am not of the camp which believes that war as we understand it must necessarily be a feature of Holocene agricultural societies, it seems likely that the pressure cooker of high population densities resulted in a radical increase in the scale of inter-group atrocity. One way to react to this change would have been to grow larger physically, but there are limitations to how fast biological evolution can resculpt the human physique. Not only that, but larger humans presumably require more nutritional inputs, and the agricultural revolution in Malthusian conditions did not enable that on a mass scale. So humans did what they do best: innovate culturally.
The cultural innovations came as package deals. A central role for patriarchal lineages which tended to apply force to maintain social order, as well as take on the position as the tip of the spear in inter-group competition, eventually resulted in power accruing to those groups almost exclusively. The importance of patrilineages naturally resulted in an increased importance of paternity certainty, and therefore social mores which emphasized female chastity. These powerful lineages fixed upon a solution which gorillas had long ago arrived at: treat females as chattel and defend them as one would property.
The “men in groups” were evoked by particular social-cultural conditions of agricultural society which they themselves did not necessarily trigger in an any way. But once you had a small benefit to the emergence of a caste of men in groups, groups which developed this caste benefited. Within these groups eventually the caste took over the identity of the group, and made its own interests conterminous with the interests of the group. The Athenian polis was democratic, but only for free males who were born of Athenians. In other words, the most radical experiment in radical democracy in the ancient world was also still relatively exclusionary and delimited in the nature of political power and representation (also, recall that the power of freeborn males of lower economic status in Athens has been connected to their importance in the navy as oarsmen).
Speaking as someone with broadly liberal sympathies, economic and social forces over the past few centuries have resulted in an unwinding of the cultural innovations of the past 10,000 years which have put a straight-jacket on the forces of human liberty. This great unwinding to some extent can be understood as the shattering of the great patriarchal monopolies of old, reflected in the great families and lineages which spanned the world, and democratic representation first for all men and then women. In the West the period between 1800 and 1970 saw massive gains in income to unskilled workers, reversing the tendency toward winner-take-all dynamics which arose with the Neolithic.
That being said, the post-Industrial and post-materialist world, in full flower in places like North Europe, is not exactly like the Paleolithic. Some of the innovations of the post-Neolithic world, such as organized religion, are probably here to stay in a world of social complexity and density. The great devolution to power from the elite male lineages is one specific aspect where I believe the modern age more resembles the Paleolithic. More liberal sexual ethics is also another dimension where the modern world is more like that of hunter-gatherers. But the autonomous individual, an island unto himself, is a fiction. Hunter-gatherers were, and are, social creatures. No doubt they were bound by taboos and rules, just as modern hunter-gatherers are. The vision of egalitarianism promoted by many in the modern West is a reaction against the social controls of the post-Neolithic world, but those social controls themselves are rooted in human cognitive impulses. Competition did not come full formed in the world of grain, and the impulse toward violence and domination was present in man long before the scythe was re-purposed toward bloodier ends.
This is a very good post. A couple of points:
1. To your point about the change in incomes after 1800, I’d add the earlier major changes in warfare, ones which “democratized” violence and greatly reduced the physical strength and life-time training advantages of having a specialized warrior caste nobility – specifically the spread of fire-arms. When your knight can be killed by a conscripted peasant with 10 weeks of training . . . it brings to mind Napoleon’s quote about Frenchmen and Mamlukes.
2. There seems to be a lot of variation within the general patriarchal trend that characterized agrarian societies with specialized warrior castes. Central Asian societies had purdah, the Roman Empire allowed divorce, and so forth. Some of them seem to even have gone down the matrilineality route while still maintaining patriarchal rules and norms. I’m curious as to how much of this is the cultural equivalent of random genetic drift – at what point was the system mostly riding off of prior inertia and the ability to violently sustain itself against challenges? There were some pretty violent challenges to the social order even as early as the Middle Ages, like major peasant revolts.
3. Do you think the rise of “men in groups with spears” with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.
before firearms: crossbows! though we need to be careful now that i think about it, as roman soldiers originally had to outfit themselves, which limited their class origins. when the state took over it opened them up to the urban proletariat, but these eventually ended up supporting their generals and eroded republican governance. so in this case the oligarchy was overthrown by an autocracy, though in practice the reality is not much changed for most people in any case....
re: #2, i assume there's contingency/drift. the roman attitude toward women is often pinned on assimilation of etruscan values. the greeks, spartans excepted, were much more exclusionary in regards to females. upper class athenian women were basically put in purdah. one way you noted aristocratic families of western origin in early constantinople is that their women did not veil themselves, while greek women did. what matrilineal societies are you talking about? they existed, but were rare (e.g., among the nairs, the iroquois). in these cultures though women were still not dominant. often they seem to be smaller scale, though matrilineal principles are present in some cultures, like ancient egypt, as a holdover.
3. Do you think the rise of “men in groups with spears” with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.
i think the men with spears predate the priestly class, because i suspect that that arose more with the fusion of tribal identity and religious beliefs. not sure how much to believe in the idea of two kings, a temporal and religious one, that you see reported by people like tacitus for tribal north europeans.Replies: @Brett
I don’t know whether you’re aware of this, but this sounds a lot like Friedrich Engels in The Origin of the Family, Private Property, and the State.
It looks like the shared ancestor of D and E1’4, at ~70 kya, significantly predates the coalescence of the major Eurasian branches ~50 kya. The latter is clearly associated with the rapid dispersal of AMH in Eurasia, around 50,000 years ago. Even the split of E-M96 into E1 and E2, which took place ~55 kya, slightly predates the major Eurasian expansion, unlike its sister D, which forms ~50 kya like the major Eurasian branches. So I don’t think it’s clear at all that DE or E (let’s not forget that DE is also found in Africa) originated outside of Africa, and even if they did, those Eurasians were most likely still confined to West Asia.
it could be within africa or west asia. i doubt they were pretty far in. as i indicate above i suspect it might have something to do with ‘basal eurasians’, who may not be part of the conventional ‘out of africa’ diaspora….
1. To your point about the change in incomes after 1800, I'd add the earlier major changes in warfare, ones which "democratized" violence and greatly reduced the physical strength and life-time training advantages of having a specialized warrior caste nobility - specifically the spread of fire-arms. When your knight can be killed by a conscripted peasant with 10 weeks of training . . . it brings to mind Napoleon's quote about Frenchmen and Mamlukes.
2. There seems to be a lot of variation within the general patriarchal trend that characterized agrarian societies with specialized warrior castes. Central Asian societies had purdah, the Roman Empire allowed divorce, and so forth. Some of them seem to even have gone down the matrilineality route while still maintaining patriarchal rules and norms. I'm curious as to how much of this is the cultural equivalent of random genetic drift - at what point was the system mostly riding off of prior inertia and the ability to violently sustain itself against challenges? There were some pretty violent challenges to the social order even as early as the Middle Ages, like major peasant revolts.
3. Do you think the rise of "men in groups with spears" with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.Replies: @Razib Khan, @PD Shaw
I’d add the earlier major changes in warfare, ones which “democratized” violence and greatly reduced the physical strength and life-time training advantages of having a specialized warrior caste nobility – specifically the spread of fire-arms.
before firearms: crossbows! though we need to be careful now that i think about it, as roman soldiers originally had to outfit themselves, which limited their class origins. when the state took over it opened them up to the urban proletariat, but these eventually ended up supporting their generals and eroded republican governance. so in this case the oligarchy was overthrown by an autocracy, though in practice the reality is not much changed for most people in any case….
re: #2, i assume there’s contingency/drift. the roman attitude toward women is often pinned on assimilation of etruscan values. the greeks, spartans excepted, were much more exclusionary in regards to females. upper class athenian women were basically put in purdah. one way you noted aristocratic families of western origin in early constantinople is that their women did not veil themselves, while greek women did. what matrilineal societies are you talking about? they existed, but were rare (e.g., among the nairs, the iroquois). in these cultures though women were still not dominant. often they seem to be smaller scale, though matrilineal principles are present in some cultures, like ancient egypt, as a holdover.
3. Do you think the rise of “men in groups with spears” with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.
i think the men with spears predate the priestly class, because i suspect that that arose more with the fusion of tribal identity and religious beliefs. not sure how much to believe in the idea of two kings, a temporal and religious one, that you see reported by people like tacitus for tribal north europeans.
1. To your point about the change in incomes after 1800, I'd add the earlier major changes in warfare, ones which "democratized" violence and greatly reduced the physical strength and life-time training advantages of having a specialized warrior caste nobility - specifically the spread of fire-arms. When your knight can be killed by a conscripted peasant with 10 weeks of training . . . it brings to mind Napoleon's quote about Frenchmen and Mamlukes.
2. There seems to be a lot of variation within the general patriarchal trend that characterized agrarian societies with specialized warrior castes. Central Asian societies had purdah, the Roman Empire allowed divorce, and so forth. Some of them seem to even have gone down the matrilineality route while still maintaining patriarchal rules and norms. I'm curious as to how much of this is the cultural equivalent of random genetic drift - at what point was the system mostly riding off of prior inertia and the ability to violently sustain itself against challenges? There were some pretty violent challenges to the social order even as early as the Middle Ages, like major peasant revolts.
3. Do you think the rise of "men in groups with spears" with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.Replies: @Razib Khan, @PD Shaw
1. I don’t think warfare had the potential to greatly reduce the physical strength/training demands until the repeating rifle, i.e. late American Civil War. Before then, the tactics were usually volley and bayonet charge. How many volleys was dependent on how quickly the enemy approached. A successful bayonet charge usually resulted in one side running away. Use of the bayonet required training and the strength/skill to perform a balanced reach, as well as the mental aggression for close combat that wasn’t present with guns.
Wasn't it more dependent on how disciplined and well-trained the troops were? From 1350 to 1914 the British always prided themselves only being able to reload and fire faster than any other army, and it seemed to work out pretty well for them in most encounters. Bayonet charges were usually employed at night or at dawn when there was an element of surprise or confusion to exploit.
And in any case warfare was a complex cat and mouse game between cavalry, infantry and artillery. Infantry could never take on cavalry for example, and cavalry were vulnerable to artillery, so it was rarely a simple case of who was fastest/boldest at charging being the most successful.
A really nice post, Razib. If anyone needs a perfect example of the profound co-evolution of cultural and biological systems, this is it.
One small quibble: the proportions of the human population actually participating in economic changes involved in the Neolithic would have represented less than 1% of the total.
These proportions did not change dramatically – in the year 3000 BC there were still may more human beings involved in hunter-gatherer economies than in farming or pastoral economies. But these in the latter economies went through a demographic transition as their rates of population increase rose, most probably due to shortened birth spacing. Even with the increased mortality and mobility due to higher rates of malnutrition, disease and violence, this transition involved post Neolithic populations to eventually swamp and absorb many of the remaining hunter-gatherer populations.
Looked at this way, you make a tremendous case for understanding the effects of an economic and organizational shift in contributing to what was, in the initial stages, a founder effect.
It was chance that determined the various specific Y and mtDNA carried by the first people who resorted to sowing seed and close management of important game animals and the subsequent increase in there descendants, but the effects of a social dynamic of lineage and economic stratification privileged certain male lines in a way that was unprecedented.
The question remains however, about whether this led to significant changes in actual selection pressures on humans, particularly on cognitive traits. Insofar as the significant environmental differences here are cultural, it seems to me that such pressures likely remained constant in direction – although there might be intensification of positive selection in favour of any polymorphisms that made cognitive assimilation of specific cultural ideals and values (particularly regarding divergent gender roles) more pronounced, but I doubt it.
I also am glad you stopped short of making Genghis Khan singly responsible for the proliferation of his particular genes. The role of his sons (including Jochi, who may not actually have been his biological offspring) as well as any people within his own lineage cannot be discounted. Any members of this lineage were likely to share many of the same genetic markers and to have passed them on, and as the fortunes of Khan rose, so did those of his kin. This means that the survival chances of the offspring of this lineage would have been, very likely, higher than average.
Very interesting post!
These proportions did not change dramatically – in the year 3000 BC there were still may more human beings involved in hunter-gatherer economies than in farming or pastoral economies. But these in the latter economies went through a demographic transition as their rates of population increase rose, most probably due to shortened birth spacing. Even with the increased mortality and mobility due to higher rates of malnutrition, disease and violence, this transition involved post Neolithic populations to eventually swamp and absorb many of the remaining hunter-gatherer populations.
i’d want to look this up, i’m skeptical that at 3000 BC we hadn’t moved beyond the tipping point.
I also am glad you stopped short of making Genghis Khan singly responsible for the proliferation of his particular genes. The role of his sons (including Jochi, who may not actually have been his biological offspring) as well as any people within his own lineage cannot be discounted. Any members of this lineage were likely to share many of the same genetic markers and to have passed them on, and as the fortunes of Khan rose, so did those of his kin. This means that the survival chances of the offspring of this lineage would have been, very likely, higher than average.
the original paper makes it clear they can’t determine with exact precision whether it was khan because they don’t have his sequence. additionally, it is not plausible that reproductive advantage ONLY to genghis khan would result in this effect. it had to be an advantage that persisted over generations, and that is in keeping with the traditional oral and written history about the value of having a genghiside origin across much of central asia.
Isn’t this statistic heavily misleading due to women’s copious body fat stores?
From http://www.ehbonline.org/article/S1090-5138%2810%2900027-9/abstract, which makes a strong case for intrasexual contests being the primary mechanism of sexual selection in men
thanks. someone brought this up on twitter. i’m going to have to look into this. that being said, *long term effective population* is then the best judge of intrasexual competition. will look at lit for gorilla and chimps…
before firearms: crossbows! though we need to be careful now that i think about it, as roman soldiers originally had to outfit themselves, which limited their class origins. when the state took over it opened them up to the urban proletariat, but these eventually ended up supporting their generals and eroded republican governance. so in this case the oligarchy was overthrown by an autocracy, though in practice the reality is not much changed for most people in any case....
re: #2, i assume there's contingency/drift. the roman attitude toward women is often pinned on assimilation of etruscan values. the greeks, spartans excepted, were much more exclusionary in regards to females. upper class athenian women were basically put in purdah. one way you noted aristocratic families of western origin in early constantinople is that their women did not veil themselves, while greek women did. what matrilineal societies are you talking about? they existed, but were rare (e.g., among the nairs, the iroquois). in these cultures though women were still not dominant. often they seem to be smaller scale, though matrilineal principles are present in some cultures, like ancient egypt, as a holdover.
3. Do you think the rise of “men in groups with spears” with patriarchal lineages and special status suppressed a rival trend of hereditary religious nobility? We see religious orders with mandatory celibacy pop up over and over again, although to be fair there were some that blurred the lines and had hereditary orders.
i think the men with spears predate the priestly class, because i suspect that that arose more with the fusion of tribal identity and religious beliefs. not sure how much to believe in the idea of two kings, a temporal and religious one, that you see reported by people like tacitus for tribal north europeans.Replies: @Brett
That’s what I was referring to – matrilineal societies that also had otherwise patriarchal norms and institutions. It makes me wonder what the source of that particular cultural innovation is. I suppose, considering the “drift” factor and the relatively low frequency of it outside of particular areas, it may just be chance and historical accident.
marvin harris in *cannibals and kings* refers to many warlike societies which go through this stage. i think one key here is that often inheritance is passed from maternal uncle to maternal nephew. these are societies with less than perfect certainty in paternity, so this is how men in groups pass their power down. eventually this just does not scale (in any case, the certainty has to be pretty low for expected relatedness of nephews to exceed sons!, i.e. e(r) = .25 vs. 0.50, even with a fudge factor on the latter). societies seem to go from matrilineal->patrilineal (e.g., parts of south india), but to my knowledge not the reverse, though one tension that emerges is that maternal grandparents are still often closer than paternal. this is true in bangladesh, where there is a disjunction between the cultural ideal of total loyalty to your father’s family, but the reality that often you are closer to your mother’s family.
Actually, the patriarchs didn’t adopt the same solution as the gorillas because gorillas do not treat females as chattels. They do not have chattels. Man treats chattels like females.
It seems to me that social stratification is a natural outcome when you consider two basic human impulses. First, the ability to only keep track of only around 150 social relationships, and only remember roughly 3,000 faces and names. Secondly, the human ability to view those “outside the circle” as being subhumans not worthy of moral consideration. For most of human history, this dynamic essentially meant once a band became too large in size – too unwieldy to be governed by the sort of quasi-democratic consensus which is the norm in hunter-gatherer societies – the natural response was to fission the group. The two daughter bands, as part of the same tribal and ethnolinguistic group, would quite likely maintain relations on some level, but they would cease to operate as one unit.
Agriculture changed the dynamics in many areas. First, it resulted in surplus which could actually be stored, which meant someone could collect the surplus value of labor. Secondly as the infrastructure of society grew more complicated (irrigation, granaries, temples, etc) there were greater and greater incentives for a band of people to not fission when it grew to an certain arbitrary size – even though it meant that traditional decision-making practices became increasingly unwieldy.
Hierarchy thus makes a certain sort of sense from a standpoint of cultural evolution. A ‘great chief” doesn’t need to know everyone – only those who are part of the elite decision-making process, who in turn interface with their own “commoners.” Even if the actual ruling class were largely parasites without particularly good ideas towards governance, they would swamp hunter-gatherers due to sheer numbers, and be able to make decisions (for good or ill) much more rapidly than any agricultural societies which had somehow maintained a more consensus-based decision making process. And as time went on, the societies which were more hierarchical would tend to win out, all things considered – at least until the development of cultural innovations like law and bureaucracy, which would allow for governance which didn’t rely directly on interpersonal relations.
i'd want to look this up, i'm skeptical that at 3000 BC we hadn't moved beyond the tipping point.
I also am glad you stopped short of making Genghis Khan singly responsible for the proliferation of his particular genes. The role of his sons (including Jochi, who may not actually have been his biological offspring) as well as any people within his own lineage cannot be discounted. Any members of this lineage were likely to share many of the same genetic markers and to have passed them on, and as the fortunes of Khan rose, so did those of his kin. This means that the survival chances of the offspring of this lineage would have been, very likely, higher than average.
the original paper makes it clear they can't determine with exact precision whether it was khan because they don't have his sequence. additionally, it is not plausible that reproductive advantage ONLY to genghis khan would result in this effect. it had to be an advantage that persisted over generations, and that is in keeping with the traditional oral and written history about the value of having a genghiside origin across much of central asia.Replies: @Helga Vierich
What do you mean by “tipping point”? Do you mean in terms of a demographic transition?
As for the percentage of the human species involved in any particular economy at any one time in history, we can only go by the archaeological evidence. At the beginning of the neolithic in all the centres, which now appear to be at least in Africa, three in Eurasia and at least two in the Americas, we have some pretty good estimates for the size of the population involved relative to the rest of humanity, and it was truly tiny. Rates of population growth of these groups involve some guess work, involving extrapolation on the rates from contemporary horticultural societies, coupled with archaeological data suggesting quite a rise in childhood mortality due to much higher rates of malnutrition and infectious diseases (and possibly parasite loads). But it took almost four thousand years for the middle eastern farmers to begin to expand into Europe, and similar time frames occur elsewhere. In Eurasia and Africa, the development of more mobile pastoral societies took as long as that before their numbers increased to the take off point when doubling times speeded up enough to leave an archaeological record of expansion.
I had estimates of between .3% and .5% population growth for the several hunter-gatherer language groups I surveyed in the Kalahari. I was actually surprised it was so high, and possibly my figures are off because I initiated vaccination programs while I was there. I thought they would be at a level closer to replacement. The other possibility was that they were already using cereal, which they got from seasonal work for farmers, as a weaning food. However this did not seem to be a big factor because the birth spacing was still rather long (for example in one group, it was 39- 56 months, mean at 48 months) and besides, I rarely saw toddlers eat more than a few mouthfuls of cooked sorghum or millet. I asked about this and the mothers laughed and said the little kids like meat or honey much more and would stop nursing for those, but not for the grains.
From the horticultural Baka (Animists) and Pastoral Fulani, that I studied in West Africa, the rates were much higher, although not as high as they would likely be now, since my data was collected before widespread vaccination. Polio was still common among Fulani for example. Still the rate of growth of population was 1.3 and 1.9 respectively, and even higher (2.19) among the Muslim Dagara and Mossi, whose farming was more intensive. I might add that puberty in girls appeared a few month earlier in the latter populations, and even as much as a year earlier than was the case for my forager sample. Birth spacing was much shorter in all the West African groups, averaging about two years.
Now you can figure out the magnitude of the demographic transition yourself from this. I frankly trust my own data more than a lot of the other estimates I have seen, but I am not pretending it is perfect. I might add that birth spacing was longer following the birth of boys than girls among the Muslim populations and this appears to be at least partly attributed to stipulations in the Quo-ran that boys should be breastfed 18 months while girls need only be suckled for 12 months.
So the forager populations were doubling every 170-180 years, while those of farmers and pastoralists would be doubling every 50 years (or less). Extrapolated over 2000 or 3000 years and it shows how dramatically different were the likely rates of population growth among post-neolithic communities and why they were forced to expand their land base, inevitably to the detriment of foragers. They may have been smaller and less healthy, but they had superior numbers, and also they likely had a lot more internal squabbling due to crowded central conditions, and specialize weapons for fighting other humans were developed at this time.
So if you accept initial estimates for the number of people involved in the early transitions to agro-pastoral systems, calculation of relative rates of population growth still leave a rather large percentage of humanity involved in foraging at 3000 BC. I figured at least half, and that agrees with other estimates made in the past from archaeological data. See, for example pages 270-275 in https://www.google.ca/search?tbm=bks&hl=en&q=Ancient+Pakistan+-+An+Archaeological+History%3A+Volume+II%3A+A+Prelude+to+Civilization+%28Google+eBook%29
I forgot to mention that the early period of the adoption of farming and livestock would have led to natural selection, to deal with digesting larger amounts of cereals and digesting milk, as well as for developing immunity to zoonotic infectious diseases form the domesticated animals. All of this would have caused childhood mortality to soar for a while. It was only once this was over, that the rates of population increase could have really begun to resemble the figures I got in West Africa.
Agriculture changed the dynamics in many areas. First, it resulted in surplus which could actually be stored, which meant someone could collect the surplus value of labor. Secondly as the infrastructure of society grew more complicated (irrigation, granaries, temples, etc) there were greater and greater incentives for a band of people to not fission when it grew to an certain arbitrary size - even though it meant that traditional decision-making practices became increasingly unwieldy.
Hierarchy thus makes a certain sort of sense from a standpoint of cultural evolution. A 'great chief" doesn't need to know everyone - only those who are part of the elite decision-making process, who in turn interface with their own "commoners." Even if the actual ruling class were largely parasites without particularly good ideas towards governance, they would swamp hunter-gatherers due to sheer numbers, and be able to make decisions (for good or ill) much more rapidly than any agricultural societies which had somehow maintained a more consensus-based decision making process. And as time went on, the societies which were more hierarchical would tend to win out, all things considered - at least until the development of cultural innovations like law and bureaucracy, which would allow for governance which didn't rely directly on interpersonal relations.Replies: @Helga Vierich
I doubt that for hunter-gatherers it was all that likely that there was any sort of tendency for everyone in a community to only remember the SAME 3000 names and faces.
In research in the Kalahari, what I found was that everyone had networks of relatives and friends that did indeed have inner circles of about 150-200 people. But everyone’s inner circle overlapped and few were exactly identical.
This meant that a married couple might between them have a total number of close friends and relatives that numbered over 200, although some of these would be friends and relatives that the wife was close to but who hardly knew the husband (at least in the beginning). It also meant that there were, for each person, an inner circle and a slightly lesser known set of people who were like a medium circle.. and then there were all the rest.
In each camping group (what is often referred to as a hunter-gatherer “band”) each person had such overlapping but not contiguous networks of close friends and relatives and most of the time, most of these people were not living in the same camp. In fact prearrangements to go camp together with someone they had been missing was one of the reasons why camp membership was so fluid and ephemeral. Individuals and family groups moved among many different lines of relationship and friendship in the course of a single year.
Most of the language groups I surveyed were under 3000 people. However since, for example Kua were often intermarried with or had (male and female) friends in the other language groups that bordered their range, such as the G/wi or the //anakwe, and most Kua tended to be multilingual, they did not regard these other language groups as “out-groups”. So the effective network of relationships of a single person, in any one community, need not limit the size of the networking of that whole group, and in fact it does not lead, among foragers, to clearcut boundaries that would demarcate such in-group vs out-group distinctions.
So, just to clarify, “bands” do not fission. They do not grow too large by natural increase. There is a yearly cycle of aggregation and dispersal, associated with waxing and waning size of actual bands of people camped out together in one location. This allows for great flexibility in adjusting local numbers to resources. The collegial exchanges of gifts, goods and personnel between different language groups furthermore permits people from one language group to seek or offer refuge at a time when local drought or other calamity occurs. Thus, this extensive networking, appears to represent a long term strategy of risk management.
I might add that the non forager Bantu-speaking agro-pastoralists with whom all these foragers were also in contact, and these WERE seen as an out-group. However any hostility the foragers might have felt or acted on, concerning invasion and usurpation of some of the vital permanent water points by these outsiders, had long since been replaced by various relationships based on seasonal employment, trade, and even some intermarriage. Notably, it was the foragers who learned the Bantu language (SeKgalahadi), not the other way around.
this is embarrassing —
It appears there are several profound arguments and perspectives encased in this article.
I’d very much like to understand them and appreciate their implications for today and tomorrow, that is, for how the world will behave for the (brief) rest of my life and for my children’s lifetimes.
The implication is, I am an older, even elderly person. I’m not dumb, but the concepts and terms you are conversant and comfortable with are at such a remove from the notions that framed my, and I daresay, my generation’s, thinking that they seem like an alien language.
We, or at least I, would desperately like to understand.
We grew up to believe that the ability to explain a topic or concept to someone who had zero knowledge but a willingness to learn, was the mark of a good teacher.
So my question/request: Have you or can you provide a primer for those who do not speak the language of genomics, so that we can understand the important information in this article?
(I could not get past the first few paragraphs — perhaps I should have plowed through to the later discussion; I thought I needed the first paragraphs for foundation.)
also, please don't use 'anonymous' as your handle.
i’ll write a simpler post soon.
also, please don’t use ‘anonymous’ as your handle.
Do you have any references to textbooks, papers or wikipedia articles that’ll help me understand what’s being presented here? I have an introductory college course level of understanding in biology.
Thanks!
Bravo, anonymous at3.21.
Great post, Razib. One of your best. It’s amazing how some ideas fit together. But I would like to know your opinion about the future, if this is possible.
In the fight between Post-Neolithic values (such as the fundamentalist Islam) or the Post-Industrial values (such as the modern West), which is the way of the future?
Will modern West suicide itself with its low birthrate and its apathy regarding immigration and the importation of foreign lifestyles? “Shall the religious inherit the Earth?, à la Kauffman. (Being an European, it seems so to me: in my home town, Muslim people are displacing natives).
Or will the modern West be able to export its lifestyle so the world will became (almost) completely Post-Industrial? (the same way the world became (almost) completely Post-Neolithic).
Anyway, thank you for a great post.
By 3000 BC, there were more farmers in the world than foragers. Lots more.
We’re basically talking about a transient here–the collapse of many forager lineages with advent of these disruptive new systems of the neolithic.
But then … the male lineages spring back and keep up, no? Patriarchy is more than this transition and some male lineages dominating.
To me anything that is actually “civilization”, requires patriarchy. Men have to organize social relations so they are *not* spending all their time fighting and mate guarding, and can get on with farming, building, designing, engineering, learning … and creating all the stuff buildings, roads, bridges, canals, metal, alphabets, ships, sewers, printing, factories, steam engines, electricity, cars, trucks, aircraft, antibiotics, vaccines, computers, nukes, the Internet … that we enjoy today.
That’s what civilized places–Europe, China, India–were able to do with patriarchal–one per customer–monogamy (religious\cultural restraints on female sexual behavior). And which for instance Africa did not really do. So some places have written languages, histories and buildings from the past and others do not. Places with patriarchy and secure paternity, benefit from surplus male labor, and can do higher investment parenting necessary for turning children into civilized adults.
I agree we have lost patriarchy in the West, and seem to be returning to some sort of much sloppier sexual norms. But they certainly don’t look more egalitarian from the male point of view. I’d bet that men in my father’s WWII generation were quite a bit more likely to pass on their genes–i.e. patrilineages were more egalitarian–than they’ll be in my son’s generation. (And the new sloppier sexual norms also don’t seem to actually make women happier!)
I’d imagine paleolithic norms were loser than the civilized ones, but still egalitarian–if the big man took too many women he’d get a spear in his back.
I’d argue we’re heading sexual relations that are sloppier and less-egalitarian. Rather than paleolithic, they seem more “African” in character–with “big state” replacing “big man” as provider. In this environment … cads have more fun. (Though how that translates into children is unclear.)
I think Western civilization is just sort of hanging on, because most of us white guys are potty trained and “do the right” thing by women, even though it’s a shitty deal. (And, of course, because of coercion by the state–high taxes, child support.) But whether this new “egalitarian” sexual model actually does sufficient high-investment parenting to produce high quality citizens to maintain the human capital generation after generation and keep civilization running … an open question.
“How many volleys was dependent on how quickly the enemy approached.”
Wasn’t it more dependent on how disciplined and well-trained the troops were? From 1350 to 1914 the British always prided themselves only being able to reload and fire faster than any other army, and it seemed to work out pretty well for them in most encounters. Bayonet charges were usually employed at night or at dawn when there was an element of surprise or confusion to exploit.
And in any case warfare was a complex cat and mouse game between cavalry, infantry and artillery. Infantry could never take on cavalry for example, and cavalry were vulnerable to artillery, so it was rarely a simple case of who was fastest/boldest at charging being the most successful.