Precision grips,hand morphology,and tools

This study asks whether there are discernable links between precision gripping, tool behaviors,

1 The term “tool behavior” has been variously used in the literature, in some cases implying exclusively tool making distinctive of humans (Susman, 1991) and in others referring variably to tool using and/or tool-making abilities, some shared with us by other animals (Susman, 1988a,b, 1994). In this paper the term is used to include both tool using and tool making behaviors of humans and non-humans; the term “tool making” is used in place of “tool behavior” whenever the discussion is focused upon distinguishing a capacity for removing flakes from stone preforms from a more general capacity to manipulate stone tools.

and hand morphology in modern hominoids, which may guide functional interpretation of early hominid hand morphology. Findings from a three-pronged investigation answer this question in the affirmative, as follows. (1) Experimental manufacture of early prehistoric tools provides evidence of connections between distinctive human precision grips and effective tool making. (A connection is not found between the “fine” thumb/index finger pad precision grip and early tool making.) (2) Manipulative behavior studies of chimpanzees, hamadryas baboons, and humans show that human precision grips are distinguished by the greater force with which objects may be secured by the thumb and fingers of one hand (precision pinching) and the ability to adjust the orientation of gripped objects through movements at joints distal to the wrist (precision handling). (3) Morphological studies reveal eight features distinctive of modern humans which facilitate use of these grips. Among these features are substantially larger moment arms for intrinsic muscles that stabilize the proximal thumb joints. Examination of evidence for these reveals that three of the eight features occur in Australopithecus afarensis, but limited thumb mobility would have compromised tool making. Also, Olduvai hand morphology strongly suggests a capacity for stone tool making. However, functional and behavioral implications of Sterkfontein and Swartkrans hand morphology are less clear. At present, no single skeletal feature can be safely relied upon as an indicator of distinctively human capabilities for precision gripping or tool making in fossil hominids. Am J Phys Anthropol 102:91–110, 1997. © 1997 Wiley-Liss, Inc.     

Genes, language, cognition, and culture: towards productive inquiry

The Queen Mary conference on “Integrating Genetic and Cultural Evolutionary Approaches to Language,” and the papers in this special issue, clearly illustrate the excitement and potential of trans-disciplinary approaches to language as an evolved biological capacity (phylogeny) and an evolving cultural entity (glossogeny). Excepting the present author, the presenters/authors are mostly young rising stars in their respective fields, and include scientists with backgrounds in linguistics, animal communication, neuroscience, evolutionary biology, anthropology, and computer science. On display was a clear willingness to engage with different approaches and terminology and a commitment to shared standards of scientific rigor, empirically driven theory, and logical argument. Because the papers assembled here, together with the introduction, speak for themselves, I will focus in this “extro-duction” on some of the terminological and conceptual difficulties which threaten to block this exciting wave of scientific progress in understanding language evolution, in both senses of that term. In particular I will first argue against the regrettably widespread practice of opposing cultural and genetic explanations of human cognition as if they were dichotomous. Second, I will unpack the debate concerning “general-purpose” and “domain-specific” mechanisms, which masquerades as a debate about nativism but is nothing of the sort. I believe that framing discussions of language in these terms has generated more heat than light, and that a modern molecular understanding of genes, development, behavior, and evolution renders many of the assumptions underlying this debate invalid.     

Neandertals and moderns mixed,and it matters

Twenty‐five years ago, the Middle‐to‐Upper Paleolithic transition in Europe could be represented as a straightforward process subsuming both the emergence of symbolic behavior and the replacement of Neandertals by modern humans. The Aurignacian was a proxy for the latter, during which enhanced cognitive capabilities explained ornaments and art. The few instances of Neandertal symbolism were deemed to long postdate contact and dismissed as “imitation without understanding,” if not geological contamination. Such views were strengthened by the recent finding that, in southern Africa, several features of the European Upper Paleolithic, including bone tools, ornaments, and microliths, emerged much earlier. Coupled with genetic suggestions of a recent African origin for extant humans, fossil discoveries bridging the transition between “archaics” and “moderns” in the realm of anatomy (Omo‐Kibish, Herto) seemingly closed the case. Over the last decade, however, taphonomic critiques of the archeology of the transition have made it clear that, in Europe, fully symbolic sapiens behavior predates both the Aurignacian and moderns. And, in line with evidence from the nuclear genome rejecting strict replacement models based on mtDNA alone, the small number of early modern specimens that passed the test of direct dating present archaic features unknown in the African lineage, suggesting admixture at the time of contact. In the realm of culture, the archeological evidence also supports a Neandertal contribution to Europe's earliest modern human societies, which feature personal ornaments completely unknown before immigration and are characteristic of such Neandertal‐associated archeological entities as the Châtelperronian and the Uluzzian. The chronometric data suggest that, north of the Ebro divide, the entire interaction process may have been resolved within the millennium centered around 42,000 calendar years ago. Such a rapid absorption of the Neandertals is consistent with the size imbalance between the two gene reservoirs and further supports significant levels of admixture.     

Attachment, mating, and parenting

A modern evolutionary perspective emphasizing life history theory and behavioral ecology is brought to bear on the three core patterns of attachment that are identified in studies of infants and young children in the Strange Situation and adults using the Adult Attachment Interview. Mating and parenting correlates of secure/autonomous, avoidant/dismissing, and resistant/preoccupied attachment patterns are reviewed, and the argument is advanced that security evolved to promote mutually beneficial interpersonal relations and high investment parenting; that avoidant/dismissing attachment evolved to promote opportunistic interpersonal relations and low-investment parenting; and that resistant/preoccupied attachment evolved to foster “helper-at-the-nest” behavior and indirect reproduction.     

Genetic-gonadal-genitals sex (3G-sex) and the misconception of brain and gender,or, why 3G-males and 3G-females have intersex brain and intersex gender

The categorization of individuals as “male” or “female” is based on chromosome complement and gonadal and genital phenotype. This combined genetic-gonadal-genitals sex, here referred to as 3G-sex, is internally consistent in ~99% of humans (i.e., one has either the “female” form at all levels, or the “male” form at all levels). About 1% of the human population is identified as “intersex” because of either having an intermediate form at one or more levels, or having the “male” form at some levels and the “female” form at other levels. These two types of “intersex” reflect the facts, respectively, that the different levels of 3G-sex are not completely dimorphic nor perfectly consistent. Using 3G-sex as a model to understand sex differences in other domains (e.g., brain, behavior) leads to the erroneous assumption that sex differences in these other domains are also highly dimorphic and highly consistent. But parallel lines of research have led to the conclusion that sex differences in the brain and in behavior, cognition, personality, and other gender characteristics are for the most part not dimorphic and not internally consistent (i.e., having one brain/gender characteristic with the “male” form is not a reliable predictor for the form of other brain/gender characteristics). Therefore although only ~1% percent of humans are 3G-“intersex”, when it comes to brain and gender, we all have an intersex gender (i.e., an array of masculine and feminine traits) and an intersex brain (a mosaic of “male” and “female” brain characteristics).     

The evolution of modern human behavior in East Asia: Current perspectives

Behavioral modernity is considered one of the defining characteristics separating modern humans from earlier hominin lineages. Over the course of the past two decades, the nature and origins of modern human behavior have been among the most debated topics in paleoanthropology. 1 - 7 There are currently two primary competing hypotheses regarding how and when modern human behavior arose. The first one, which we shall term the saltational model, argues that between 50–40 kya modern human behavior appeared suddenly and as a “package”; that is, the entire range of traits appeared more or less simultaneously. The proposed reason most often cited for this sudden change in behavior is a genetic mutation, possibly related to communication, 7 that occurred around 50 kya. The second major hypothesis, which we shall term the gradualistic model, argues that modern human behavior arose slowly and sporadically over the course of the past 150,000 years and may be related to increasing population pressure. 2 In general, many European scholars subscribe to the saltational model, while many Africanists seem to prefer the gradualistic model. As McBrearty and Brooks 2 noted, the disagreement may be related to different developmental histories underlying the research traditions in Europe and Africa.     

The ripples of modernity: How we can extend paleoanthropology with the extended evolutionary synthesis

Contemporary understandings of paleoanthropological data illustrate that the search for a line defining, or a specific point designating, “modern human” is problematic. Here we lend support to the argument for the need to look for patterns in the paleoanthropological record that indicate how multiple evolutionary processes intersected to form the human niche, a concept critical to assessing the development and processes involved in the emergence of a contemporary human phenotype. We suggest that incorporating key elements of the Extended Evolutionary Synthesis (EES) into our endeavors offers a better and more integrative toolkit for modeling and assessing the evolution of the genus Homo. To illustrate our points, we highlight how aspects of the genetic exchanges, morphology, and material culture of the later Pleistocene complicate the concept of “modern” human behavior and suggest that multiple evolutionary patterns, processes, and pathways intersected to form the human niche.     

麋鹿行为谱及PAE编码系统

以麋鹿为实例,通过辨识行为的基本单元,区别了“姿势”、“动作”和“环境”,分解了动物行为的层次,然后根据行为的适应和社群机能归类,建立了以“姿势—动作—环境”为轴心的,以生态功能为分类依据的动物行为分类编码系统（PAE编码分类系统）。PAE编码分类系统以集合论为基础,明确了动物行为的三要素：姿势、动作和生态环境之间的关系,避免了笼统地将动物的姿势、动作和行为混为一谈的做法,区分了动物行为的组成要素和结构层次。行为要素编码方法为动物行为学研究提供了一个新的生长点。在继承前人工作的基础上,记录了有关麋鹿的姿势、动作和行为达200多种,还区别了各种行为在雄性、雌性和幼体之间的相对发生频次以及发生季节。     

An ethological study of pygmy chimpanzees in Wamba,Zaïre: A comparison with chimpanzees

An ethological study was conducted on a provisioned pygmy chimpanzee group in Wamba, Zaïre and was compared with the author's previous study on common chimpanzees, in Mahale Mountains with special reference to the evolution of behavior systems. The relationships between behavior patterns were investigated by analyses of the intra- or inter-individual sequential behaviors. Analysis of behavior pathways showed that “bipedal” was not found (i.e., observed frequency lower than expected value) in the course of the charging display in pygmy chimps, though it was an important element of the charging display in common chimps. Additionally, “bipedal” was found to be an initating behavior pattern in sexual behavior or dominant-subordinate behavior in pygmy chimps. These differences were related to the decrease of the role of charging display and to the increase of the roles of sexual and dominant-subordinate behaviors in pygmy chimps. Sexual behavior, “female genito-genital rubbing,” “mutual present” and frequent mounting and presenting between males were suggested to have evolved together as a system. These characteristics of behaviors correspond to the fact that pygmy chimps form more stable and larger temporary groups than common chimps.     

Petite bodies of the “robust” australopithecines

The “robust” australopithecines are often depicted as having large and powerfully built bodies to match their massive masticatory apparatus, but until 1988 the sample of postcranial remains attributed with certainty to this group was very limited. Almost nothing was known about the body of the East African “robust” australopithecine because taxonomic attribution of the postcrania was so uncertain. The body of the South African “robust” australopithecine had to be reconstructed from about a dozen isolated fragments of postcrania. Now a partial skeleton is attributed with confidence to the East African “robust” group along with several isolated bones. The South African sample has more than tripled. Analyses of this vastly expanded sample reveal that a large portion of postcrania attributed to “robust” australopithecines from Swartkrans Member 1 (35%) are from extraordinarily small-bodied individuals similar in size to a modern Pygmy weighing as little as 28 kg. These small elements include parts from the forelimb, spine, and hindlimb. About 22% of these Swartkrans 1 “robust” australopithecines are about the same size as a modern human weighing about 43 kgs and about 43% are larger than this standard but less than or equal to a 54 kg modern human. Approximately the same pattern is true for the Swartkrans 2 hominids, but taxonomic attribution is less certain. All of the Member 3 specimens are similar in size to the 45 kg standard. The partial skeleton of the East African “robust” australopithecine (KNM-ER 1500) has hindlimb joints that would correspond to a modern human of 34 kgs although the actual weight may be 5 to 10 kgs greater judging from shaft robusticity and forelimb size. The largest postcranial element attributed with some certainty to the East African “robust” australopithecine group (the talus, KNM-ER 1464) is about the same overall size as a modern human of 54 kgs, although its tibial facet is slightly smaller. Although many previous studies have hinted at the possibility that “robust” australopithecines had relatively small bodies, the new fossils provide substantial evidence that these creatures ranged from quite small to only moderate in body size relative to modern humans. These were the petite-bodied vegetarian cousins of our ancestors. Sexual dimorphism in body size appears to be greater than that in modern humans, similar to that in Pan, and less than that in Gorilla or Pongo, although such comparisons are of limited value given the small samples, poorly known body proportions, time averaging, and many other problems.     

SYMMETRY,LOCOMOTION, AND THE EVOLUTION OF AN ANTERIOR END: A LESSON FROM SEA URCHINS

Bilaterally symmetrical, “regular” sea urchins in the Family Echinometridae (Class Echinoidea; Phylum Echinodermata) were found to lack a locomotor anterior. Heterocentrotus mammillatus and Echinometra mathaei were observed while locomoting. Members of both ellipsoidal species were found to proceed with their short or long axis foremost with statistically equivalent frequencies. This finding demonstrates that the evolution of bilateral symmetry is not always accompanied by the evolution of a locomotor “anterior” end. The elliptical echinometrid sea urchins provide a particularly appropriate study group for investigating the relationship between the evolution of body form and locomotor behavior. Although the radially symmetrical regular sea urchins, from which the echinometrids sprang, lack a locomotor anterior, all “irregular” echinoids, which are also derived from a regular ancestor but are bilaterally symmetrical, possess an “obligate” locomotor anterior. The symmetry and behavior exhibited by the elliptical echinometrid sea urchins therefore demonstrates that the first irregular echinoids (which exhibit bilateral symmetry by definition) need not have possessed a locomotor anterior as they do today.     

Innovation and technological knowledge in the Upper Paleolithic of Northern Eurasia

The technology of modern humans is unique in the animal kingdom with respect to its complexity and capacity for innovation. Evidence of technological complexity and creativity in the archeological record is broadly coincident with and presumably related to traces of creativity in art, music, ritual, and other forms of symbolism. The pattern of modern human technology is part of a larger package of behavior (sometimes referred to as “behavioral modernity”) that emerges with the appearance of industries in Eurasia classified as Upper Paleolithic, but has deeper roots in the African Middle Stone Age. 1 - 5 .     

Behavior of males in a reproductive aggregation of the banded demoiselle Calopteryx splendens (Insecta, Odonata)

The view according to which damselfly males practice two alternative reproductive tactics of access to females is critically discussed. It is widely accepted that some males (“territorial” ones) have priority as potential female partners, while others (“sneakers” or “wanderers”) are incapable of retaining an individual territory. They have a chance of mating only by intruding briefly into the area defended by a “territorial” male when a female is present there. Thus, the tactics of a “territorial” male consists in waiting for a female in its territory and copulating with it “by agreement,” whereas non-territorial males resort to forced copulations. By observation of individually marked males (48 out of 118) it was shown that every male could be regarded as “territorial” during a certain period and as a “wanderer” before and after it. Thus, no correlation between the modes of space use by a male (residence/mobility) and the characters of its external morphology and/or signal behavior appears to be possible in principle. According to the data obtained, a more plausible explanation is that the female chooses not the male but the best area for oviposition. In addition, it was ascertained that adherence to forced copulations cannot constitute successful “tactics” since they rarely result in insemination, neither by “territorial” nor “non-territorial” males. In other words, we are dealing not with certain alternative tactics (i.e., specialized adaptive mechanisms that have evolved in the species) but simply with the results of different sets of circumstances at a given moment.     

Exclusion and shunning as legal and social sanctions

It seems difficult to determine which behavioral propensities are part of human biology and which are the results of cultural influences. If specific behavior patterns occur (perhaps with some variations) in all or most cultures, one might assume that they are based on innate behavioral tendencies. Exclusion and shunning are part of behavior patterns that have occurred again and again in various cultures throughout all recorded history as a response to deviant or abnormal behavior. This article examines the particular origins of the practice of “Ostrakismos” in ancient Athens, and its relationship to exile or exclusion from the legal community in various human cultures. With primitive peoples, and as evidenced in the laws of ancient Rome and medieval European kingdoms, outlawry was long a formalized sanction; also both Catholic and Lutheran religious laws provided explicitly for excommunication. In contrast, modern legal communities are less likely to exercise such formal expulsion of a member except under relatively extreme circumstances. The various data examined here may contribute to a comparative analysis of the behavior pattern “Exclusion and Shunning.”     

Anthropomorphic effigy vessels from Chupicuaro,Mexico*

The subjectivity of the anthropologist is grounded in the historical and ideological worlds in which he is positioned. The author finds the basis of his comparison of Australian and Sinhalese Buddhist nationalisms in the Australian cultural context, which leads him to a particular construction of the Sinhalese “otherness”. The Australian egalitarian nationalism and the Sinhalese Buddhist hierarchical nationalism are traced as ideologies through a range of practises, showing differing relationships between nation and state. Both nationalisms, the author argues, are to be understood as equally “modern” .     

News photography and indigenous peoples: An “encounter” in Guatemala

In March, 1991, a “Continental Encounter” of indigenous peoples took place in Quetzaltenango, Guatemala. This paper examines the photographic coverage of that event, based on interviews with the journalists, observation of their work at the Encounter, and analysis of published reports and photos. The news coverage is divided into three phases: expectations (in search of the exotic “type”), transformations (rethinking “Indianness”), and negation (institutional disregard). It is argued that the news media represent indigenous peoples as part of a “vanishing” past; exotic “others” whose existence has no relevance to the “modern” news consumer.     

A Two-Stage Test for Distinguishing Random,Pseudo-Random and Nonrandom Mating Populations

There is no such an implication that a population in Hardy-Weinberg equilibrium must have undergone random mating. Therefore, it is unequivocal that the usual tests for “Hardy-Weinberg equilibrium” are indeed tests for “random union of gametes” but not for “random mating”. In this paper, utilizing population characteristics expressed in equilibrium state (equilibrium or disequilibrium) and mating behavior (random or nonrandom), a two-stage testing procedure for distinguishing random, pseudo-random and nonrandom mating populations is proposed. At the first stage, a population is tested for Hardy-Weinberg equilibrium. If insignificant result (i.e., in equilibrium) is obtained, then to a second stage the population is further tested for mating behavior. Random mating-pairs data are needed here for analysis instead of random individuals for usual Hardy-Weinberg equilibrium tests. Since distinguishing the three types of mating populations depends on the combined results of two stages, the probability of correct determination of the two-stage tests is discussed by simulation studies.     

Behavior of red wood ants (Hymenoptera,Formicidae) during interaction with different symbiont partners

A comparative analysis of the behavior of Formica polyctena Först during interaction with different symbionts (free-living aphids Aphis grossulariae Kalt. and hidden larvae of the sawfly Blasticotoma filiceti Klug) was carried out. Red wood ants demonstrate different levels of functional differentiation in relatively constant groups of foragers collecting honeydew. A deep “professional” specialization with clear division of a number of tasks among foragers was studied in groups of ants tending aphids. Four professional groups of foragers with different tasks were revealed: “shepherds,” “guards,” “transporters,” and “scouts” (or “coordinators”). The groups of foragers caring for sawfly larvae mainly consist of unspecialized ants. Only few ants (about 5%) remain on duty on the fern plant near B. filiceti larvae and protect the food resource from competitors, especially from other ants. In addition, the ants demonstrate simpler behavior while collecting the larval excretion, resembling that at the sugar feeders. On the whole, the behavior of red wood ants is rather flexible. The level of functional differentiation in groups of foragers collecting honeydew is determined not only by the colony size and requirements but by the nature of their interaction with trophobionts, particularly, by the possibility of direct contact.