The Evolutionary and Ecological Roots of Human Social Organization

Kaplan et al., in their article, “The evolutionary and ecological roots of human social organization,” argue that shifts in production strategies cause changes in social organization. Shifts in production strategies include the utilization of land for agriculture, domestication of animals for pastoralism both of which result in changes in social organization such as the societal value on skill, inter and intra group competition and the conditions necessary to institute coercive authority and domination. The authors discuss the reasoning behind the high value of skill and knowledge within the human adaptive complex; due to the human dependence on high-quality and therefore difficult to acquire food, skill and knowledge are highly valued to sustain the described diet. The high value of skill and knowledge result in longevity and lowered mortality rates, both which are uniquely human characteristics.

The authors discuss four major sustenance strategies and their differences in value of skill, cooperative relationships and dominance among other factors. Egalitarian societies are characterized by a high value on skill and knowledge and cooperative production and the sharing of food resources which result in relationships characterized by cooperation. While the value of skill is variable, but generally highly valued in egalitarian societies, it tends to decrease in tribal horticulture. In tribal pastoralism, skill and knowledge is a prerequisite to efficiency of herd management; however, herd size rather than time and labor investment, including the time investment in acquiring knowledge is the determinant to pastoral productivity. Also, frequency of warfare and the paralleling need for leadership increases dramatically within this strategy. The rise of agrarian states witnessed the increase in land inheritance which the authors argue directly affects the societal value of skill, due to the fact that the child’s wealth is generally predetermined. This strategy is also characterized by dramatically increased levels of inter and intra group competition followed by severe social stratification. Social stratification in these early agrarian states was pinnacled with despotic males who capitalized on social power by the disposing of rivals, increased access to land, slaves and wealth as well as the ability to determine who their political successor would be. The authors conclude that while investment in acquiring skill and knowledge is a marked characteristic of egalitarian societies, the value of such investment decreases with the utilization of other strategies, especially land and cattle due to the fact that they are inheritable. The authors also include the interesting comparison of contemporary skill-based economies and skill-based economies of hunters and gatherers. They argue that the two are similar and both result in social and political structures that resemble egalitarianism as well as an increased individual freedom.

Gurven, M. Hooper, P. Kaplan, H.

2009 The Evolutionary and Ecological Roots of Human Social Organization. Philosophical Transactions of the Royal Society. Bilogical Sciences. Pp. 3289-3299

Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure

Human social structure and grouping are unique and may have a lot to do with our success as a species. This social structure appears to be based on cooperation with unrelated individuals and a reliance on cultural transmission. The ancestral form of human patterning has been argued to be either female philopatry with maternal grandmother provisioning, or male philopatry with adult male provisioning. Both of these hypotheses suggest grouping by kin and inclusive fitness as the primary reason for any cooperation.

An alternative model, proposed by Bernard Chapais suggests that partnerships of males revolving around a single related female could bridge relationships between different lineal groups. One way of achieving this is marriage of daughters to an unrelated but local group, creating a familial bond between the two groups. This would allow for greater interaction and visitation between groups and a high number of co-resident adults who are not genetically related. Between groups of large enough size, social networks will also be large and can lead to increased observation of rare innovations. The rate of social and cultural evolution would increase and lead to more complex social structure.

Hill et al. analyzed data of band composition from a worldwide sample of 32 hunter-gatherer societies. In the majority of the societies (19) there was no difference between parents living with adult sons versus daughters. In general the total number of co-residing male primary kin is higher than the number of co-residing female primary kin. There is also a pattern of frequent brother-sister co-residence that can be seen across all ages, not just for during ritual bride service.

Hill et al. more specifically analyzed 58 precontact Ache bands and 6 bands of Ju/’hoansi. Smaller Ju/’hoansi bands contain a greater proportion of primary kin, whereas larger Ache bands contain a higher proportion of distant kin. Kin of a family unit only make up about 40% of the co-resident adult members of a band. “Distant affines” or kin of kin make up about half of the co-resident adult members of a band. Finally about 25% of all the individuals in a band are not linked by family ties.

In general, the bands of the 32 societies are composed of distantly related or unrelated individuals. Primary kin generally make up less than 10% of these residential bands, although not much other information of these 32 societies is given. Given the large amount of movement of individuals and cooperation between groups, there would be a pressure for the evolution of positive social mechanisms. The large the populations of the two groups, the more frequent the interactions would be and the faster any cultural innovations may be transmitted and adopted. This is one possible explanation for why humans evolved social learning mechanisms that resulted in cumulative evolution.

Kim R. Hill, et al. 2011 Co-Residence Patterns in Hunter-Gatherer Societies Show Unique Human Social Structure. Science 331: 1286-1289.

Chumash Canoe Specialization

The Chumash plank canoe (tomol) was a highly specialized and effective tool for the Chumash people. It has been argued that the development of this technology played a crucial role in the sociopolitical evolution of the Chumash. However, the debate lingers as to the actual provenance for invention of the plank canoe. Were the Cumash, a complex hunter-gatherer people, able to construct an intricate and complex tool on their own, or did they, as some have suggested, rely on external influence from Polynesia to guide construction? Jeanne Arnold’s article delves into multiple data sets in order to extrapolate who was responsible for the initial invention of the tomol.

The tomol were highly valued and, as such, were only in the possession of chiefs and certain elites. This was due to the high costs in producing the craft. The tomol required nearly 500 days of skilled labor and a sufficient quantity of material, such as redwood, that was not available locally. However, when completed the craft was six to seven meters in length and could hold 12 passengers or 2-tons of cargo. The ability to transport large quantities of cargo is essential in the expansion trading systems and the ability to capture large bodied fish.

Direct evidence for the construction or construction areas for the tomol are based on the presence of two main items; asphaltum, a sticky substance used to make the ships watertight, and redwood, used to construct the planks. While the indirect evidence of invention and widespread use of the tomol relies on the appearance of cross-channel movement of highly prized trade goods and heavy objects such as mortars, that would have been difficult to transport in any other fashion.

Based on these criteria, multiple techniques have been used to date the inception of the tomol. Radiocarbon dating of planks at a San Miguel Island site reported a calibrated date of A.D. 625-700. However, there has also been a strong case for using a database of fish remains form the Santa Barbara Channel to help date the tomol. The results of this study to a period between A.D. 500-600, in which a steady number of larger species of fish appear at coastal villages. It also appears that the movement of highly prized trade goods begins to be accelerated after A.D. 600-700. Based on the culmination of results from nearly a dozen sites, Arnold argues that at the date of A.D. 500 plus/minus a century is the most likely date for the invention of the tomol.

Based on an accepted date for the invention of the tomol, it is possible to delve into a possible Polynesian connection. However, given the early date of the invention of the tomol, it is highly improbable that there was any connection between the two groups. The earliest dates for colonization by Polynesians in the Hawaiian Islands dates no earlier than A.D. 800, and at Easter Island, that date is identified at A.D. 1200. These dates are far too recent to demonstrate a Polynesian influence on tomol invention. The dates also coincide with the fact that both construction techniques and the physical manifestation of the crafts are highly dissimilar. This clearly demonstrates that the Chumash was able to formulate a complex technological system in the creation of their specialized watercraft.

Arnold was able to demonstrate through empirical data that a complex hunter-gatherer population was able to manifest highly complex technological innovation without the influence of “an agricultural society”. The Chumash was able to develop a complex system, in which a vertical hierarchy was able to provide the social and economic capital necessary for social and technological innovation. In turn, Innovation was able to expand a network of exchange and craft specialization, thereby, firmly establishing Chumash political and social complexity.

Arnold, Jeanne E.

2007 Credit Where Credit is Due: the History of the Chumash Oceangoing Plank Canoe. American Antiquity 72(2): 196-209.

Envisioning San History

Benjamin Smith writes about past attempts at creating an historical account of the San people that uses strictly indigenous sources without outside influences. For Thomas Dowson, the only way to do this was to use the native rock art. Neither historical records collected and written by non-San, nor interpretations of archaeological remains by the west could be used in this endeavor because they were corrupted by values and preconceptions that were not help by the San.

In 1994 Dowson examined the changing role of shamans through time with three different categories of rock paintings. In these rock paintings, shamans are first depicted as the same as the rest of the people, then small shaman groups are painted more elaborately than adjacent groups, and lastly a single shaman is painted larger and more elaborately than adjacent people. The drawback with this interpretation is that it lacks chronological context. Without dating, there is no way to know the duration of these changes and if they relevant to the contact period.

In 2004 Geoff Blundell continued Dowson’s work on rock art and shamans. He characterized different sets of rock art as ones of translucent spirits, crudely depicted contact animals such as cattle, and significantly differentiated figures. He argued that the San already had developed concepts of individuality and powerful shamans before interactions with other peoples. Although the regional focus was the strength of the study, again the lack of historical context could place the change anywhere within the last few thousand years.

In 2008 Sam Challis used a mix of historical sources, archaeology, and oral traditions to determine the symbolic system used by a particular group. He was able to track the use this symbolism through time. With these varying sources, he was able to balance perspective to produce an insider view into San culture and situate it in a specific time period.

Smith concludes that ultimately, even the rock art is subject to interpretations of the viewer and can’t fully speak for people who are gone. Also unless the artwork can be directly dated, the interpretations must rely on contextual clues for a time period. A combination of sources is needed to ensure that an outsider perspective doesn’t dominate the account. Regardless rock art has an important role to play in the future of inclusive histories.

Smith, Benjamin W. (2010) 'Envisioning San History: Problems in the Reading of History in the Rock Art of the Maloti-Drakensberg Mountains of South Africa', African Studies, 69: 2, 345 — 359

The extraterrestrial hypothesis

In 2007 a paper was written by Firestone hypothesizing an extraterrestrial airburst or impact in nothern North America that caused the Younger Dryas event, caused megafaunal extinction, and the termination of the Clovis culture. A carbon-rich black layer dating to 12.9ka has been identified at 50 Clovis-age sites and is contemporaneous with the onset of the Younger Dryas. Bones of extinct Pleistocene megafauna and Clovis tool assemblages occur below the black layer but not in the layer or above it. Clovis-age sites are overlain by a thin, discrete layer with varying peak abundances of magnetic grains with iridium, magnetic microspherules, charcoal, soot, glass like carbon containing nanodiamonds, and fullerenes with extraterrestial helium. The layer also extends through 15 Carolina Bays which are unique elliptical depressions that are oriented northwest across the Atlantic Coastal Plain. Evidence suggests that the extinction of mammalian and avian taxa occured catastrophically at the onset of the Younger Dryas. In North America 35 mammalian genera disappeared. At Murray Springs, AZ (Clovis site), mammoth bones and Clovis tools lie below the black layer but not above it. Firestone believes the extinctions are too broad and ecologically deep to be explained by either overkill or climatic cooling hypotheses. He lays out his evidence very well. Magnetic microspherules measuring 10-250 um peaked in or near the Younger Dryas boundary at 8 of 9 Clovis sites tested. Microspherules are most abundant in the north with a peak of 2144 per kilogram at the Paleoindian site of Gainey, MI. Magnetic grains measuring 1-500 um show a peak at the Younger Dryas boundary at all 10 Clovis sites tested. And again the abudances are higher in the north. Iridium was found at levels up to 5000 times higher than typical crustal abundance at 9 of 14 Clovis sites. And iridium was only found at the black mat layer and not above it. Charcoal displays peaked at the Younger Dryas boundary. High temperature polycyclic aromatic hydrocarbons were found in the Younger Dryas boundary layer but no above it suggesting intense fires occured at locations that were tested. Carbon spherules found at the P/T boundary (a suggested cosmic impact that created a mass extinction 250mya) are similar to the spherules found in the black mat of the Younger Dryas boundary. The spherules contain fullerenes and nanodiamonds which are extremely rare on Earth but are found in meteorites and at extraterrestial impact sites. Evidence of biomass burning is found in the ice cores of Greenland which show large spikes of ammonium and nitrate markers. Some megafuanal bones studied at the Younger Dryas boundary were highly roadioactive relative to bones in stratigraphic layers before the Younger Dryas boundary. All this evidence leads Firestone to the conclusion that a comet hit the Laurentide ice sheet causing huge amounts of meltwater to pour into the North Atlantic and caused the MOS cycle to be disrupted. Biomass burning and mass extinctions took place as well. The comet is hypothesized to have released 10e7 megatons of energy when it impacted and it was probably around 4km in size. But where's the crater? If the comet impacted at less than 30 degrees it would not have left a crater. Or if it broke up on the way to impact it wouldn't necessarily leave large craters. While all this is certainly plausible Firestone makes inferences about the effect this had on the Paleoindians that are not supported by any evidence. He claims major adaptive shifting by Paleoindians occured around 12.9kya. But no evidence of this exists. He claims a population decline and bottleneck occured at this time as well, again no evidence supports this. Other archaleologists attempted to recreate his evidence of iridium, spherules, etc., but couldn't detect anything at the level that Firestone did. Something happened at the 12.9kya Younger Dryas boundary, but it most likely wasn't an extraterrestrial impact. Firestone RB. Evidence for an extraterrestial impact 12900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling. PROCEEDINGS- NATIONAL ACADEMY OF SCIENCES USA, 104, no. 41, (October 9, 2007): 16016-16103

A New Lease on Life for Submerged Paleolithic Sites?

     "The rarity of Pleistocene hunter-gatherer sites along the coasts of Western Europe led to a virtual consensus among archaeologists in the late 20th century that Palaeolithic people largely ignored this type of environment" (Bicho and Haws 2008 pg 2166).  This quote may reference Western Europe yet the same could be said of Paleolithic people in countless coastal areas worldwide.  Is there truly a paucity of Pleistocene sites along coasts or have we just not yet located them?

    While Bicho and Haws' article argues for the use of coastal resources in Pleistocene times, their article also brings to the forefront that coastal sites are present; just not "viewable".  As Bicho and Haws state in the conclusion of their article, "most Palaeolithic coastal sites are now-submerged" (Bicho and Haws 2008 pg 2173).  This is as true in Portugal as it is in the United States.

   However, two researchers from Mercyhurst College are working with NOAA (National Oceanographic and Atmospheric Administration) and their underwater grants program to open up the study and understanding of landforms of long flooded coastal areas.  What these researchers, James Adovasio and C. Andrew Hemmings hope to do is open to "view" (in a manner of speaking) the expanses of coastline that have been submerged since the Last Glacial Maximum (LGM).

    They started their fieldwork in 2007 studying the submerged coastline west of St. Petersburg, Florida.  Using sub-bottom profiling and side-scan sonar, their team looks, "at everything from the LGM beach to the modern shoreline...for things like prehistoric river channels, sinkholes, and the like" (Largent 2011 pg 8).  Their expectation is to locate late Pleistocene sites at submerged areas they have targeted because, "early occupation sites on shore were almost invariably chosen with ready access to freshwater and toolstone (Largent 2011 pg 9).  To date Adovasio and Hemmings have located the ancient river channels of the Suwannee and St. Marks rivers as they once flowed across the continental shelf off of western Florida.  As well, they have found submerged chert outcrops (Largent 2011 pg 8).  And where rivers and chert are found on dry land in Florida, Hemmings says places such as those are where, "massive Paleo sites" (Largent 2011 pg 9) are found.

    There naturally are complications to intensive underwater archaeology.  Deep dives, "limited air supplies and the need to avoid decompression", and expenses (Largent 2011 pg 9), combine to contrict fieldwork.  What this team has found so far may seem trivial to many, however; every advance that comes from their work is able to help other researchers elsewhere to possibly identify characteristics that, while presently submerged, when dry may have been the site(s) of any number of Paleolithic people.  This research can only enhance and expand on what we already know about Paleolithic people and how they used coastal areas.


Bicho, N., and J. Haws
           2008 At the land's end: Marine resources and the importance of fluctuation in the coastline in the
           prehistoric hunter-gatherer economy of Portugal. Quaternary Science Reviews 27:2166-2175.

Largent, F.
           2011 Prehistoric florida submerged. Mammoth Trumpet 26(1):7-10.

Big-game Hunting and the Politics of Paleoindians?

The traditional view of early Paleoindian groups has maintained that these populations roamed the countryside, armed with high quality stone points in pursuit of megafuana. However, this may be an oversimplification of the patterns in Paleoindian lifeways and the role of the hunt on social organization. What was the real role of big-game hunting for early Paleoindian in North America? Are our traditional assumptions of early Paleoindian behavior still viable when compared to modern ethnographic counterparts? John D. Speth, Khori Newlander, Andrew A. White, Ashley K. Lemke and Lars E. Anderson attempt to rock the boat of basic assumptions about Paleoindian systems in their article Early Paleoindian big-game hunting in North America: Provisioning or Politics?, by asking seven key questions that are meant to bring about a new way of thinking about and perhaps understanding Paleoindian behaviors.

“Were big game … really the mainstay of the Paleoindian diet” (Speth et al. 2010:2)? Speth et al. assert that large game hunting did take place, but acknowledge that a shift in evidence is pointing to a population that were “generalist” in their food intake rather than hunting specialists. Is it possible to address the view that these populations were specialized hunting groups, especially when much of the small faunal and floral remains are lost to time due to taphonomic processes?

“Do the distances from kills and campsites to sources of exotic flint reflect the actual geographic space over which Paleoindian groups ranged on an annual basis” (Speth et al. 2010:2)? “Why did flint procurement have to be embedded in the annual round of a social group? Why couldn’t the get it through exchange… or periodic treks to the sources for the express purpose of getting flint” (Speth et al. 2010:2)? Understanding lithic procurement strategies are a decisive factor in developing a cohesive model for Paleoindian behavioral practices. There are numerous accounts in the ethnographic literature of individuals and small groups willing to travel long distances to acquire symbolically important materials, distances beyond the typical scope of the annual subsistence round. Is it possible that flint may have fallen into this category of a symbolically meaningful resource to Paleoindian populations especially from non-local sources? There is also the potential that Paleoindian group’s acquired flint through economic and social exchange with other groups. Based on the ethnographic record, groups had the ability to transport exotics beyond the scope of basic subsistence needs and have been observed doing so. Speth et al. wants to move beyond the traditional utilitarian and economic explanations of resource movement, and bring in aspects of social, political and ideological forces into the mix, in order to have the ability to formulate a comprehensive assessment.

“Why all the hoopla about “high-quality flint in the first place …” (Speth et al. 2010:3) and “Why are Paleoindian projectile points so remarkably pretty?” (Speth et al. 2010:3)? If quality flint was vital to a group’s survival then the use of poor quality flint would be nearly absent in the archaeological record, but it is medium to poor quality stone that is the most prevalent. Fine quality flint is mainly observed in use as projectile points. However, why would you use material of high quality and of greater value in a method that it would be apt to break? “Does one really need a stone point on the end of a projectile weapon to kill an animal?” (Speth et al. 2010:3)? The basic answer is no. Wood-tipped arrows have been proven effective in not only hunting, but also warfare. Speth et al. raise the idea that high-quality stone points may lay in the realm of costly-signaling rather than basic survival.

The last and most pertinent question raised by Speth et al., is whether big-game hunting was merely for food procurement for the survival of the family or were the hunts taking place for social and political prestige. Speth et al. seem to favor the idea of prestige as an underlying goal of the hunt. Based on archaeological and ethnographic information, the hunt is not always the most beneficial method for a groups subsistence needs, but rather is available when subsistence needs are already met. The hunt itself becomes part of costly signaling.

Speth et al. raise several intriguing and fundamental question about Paleoindian behavior practices from a perspective that is rarely tackled. Even they acknowledge that the article was entirely speculative. It was meant to raise more questions than answers by providing a distinctly new social, political and ideological approach to Paleoindian lifeways. In this regard, they accomplished their task. The distinct set of seven questions posed by Speth et al. was able to build upon each other to help support understanding the next question until they culminated in a plausible alternative to traditional Paleoindian models. The use ethnographic analogous groups to support their perspective provided valuable comparative analysis, but they need to root their fundamental assumptions on hard archaeological evidence to solidify their model. As of now their assumptions are extremely generalized across the broad geographic landscape of North America, and therefore, may not be applicable to all Paleoindian groups. They have succeeded in laying the groundwork for a new approach to Paleoindian lifeways; however, they still have a long way to go before they can rewrite the traditional understanding of Paleoindians.

John D. Speth, Khori Newlander, Andrew A. White, Ashley K. Lemke and Lars E. Anderson

2010 Early Paleoindian Big-Game Hunting in North America: Provisioning or Politics?Quaternary International: in press.