Neo-Darwinism,niche construction theory,and the initial domestication of plants and animals

The initial domestication of plants and animals and the subsequent emergence of agricultural economies, which began independently more than 10,000 years ago in a number of different world regions, represent a major evolutionary transition in earth history. It is these domesticates, and the agricultural economies based on them, that have formed the lever with which humans have substantially modified the earth’s terrestrial ecosystems over the past ten millennia. General explanations for this transition from hunting and gathering to food production economies formulated over the past 40 years have been based on standard evolutionary theory (SET) and employ the assumption of unidirectional adaptation—that environments change and species adapt. Here I compare these proposed SET—based externalist explanations for domestication with a recently formulated alternative developed from niche construction theory (NCT). Archaeological and paleoenvironmental records from two independent centers of domestication in the Americas—eastern North America and the Neotropics of northern South America, are found to support the NCT-based explanatory approach but not the SET explanations, underscoring the limitations of externalist SET approaches and the need for broader conceptualization of the processes that direct evolutionary change in order to gain a better general understanding of initial domestication as well as other major evolutionary transitions.     

Morphometric Analysis of Sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) Achenes from Mexico and Eastern North America<Superscript>1</Superscript>

Morphometric Analysis of Sunflower ( Helianthus annuus L.) Achenes from Mexico and Eastern North America. Sunflower (Helianthus annuus L.) has played a major role in the evolution of agricultural systems in the Americas. The discovery of ancient domesticated remains from archaeological deposits in pre-Columbian Mexico offers new dimensions to widely accepted viewpoints on the domestication pattern of H. annuus. Although American sunflower populations north of Mexico have been examined extensively, Mexican indigenous domesticated landraces have not been studied in any detail. In this study, we morphologically assessed wild and domesticated sunflower achenes from Mexico and compared them to similar datasets from eastern North America. Additionally, we evaluated the utility of four computer-assisted shape measurements in discriminating between wild and domesticated sunflower achenes (fruits) and compared variation in achene size among modern wild and cultivated populations from both Mexico and the U.S. We found that, of the shape parameters tested, none were informative in distinguishing wild achenes from domesticated varieties. Subsequent size analysis, using conventional parameters of length, width, and thickness, showed that modern wild populations from Mexico had smaller achenes compared to modern populations from eastern North America. Domesticated achenes unearthed from Mexican archaeological sites, however, were significantly larger than the early domesticated specimens recovered from eastern North America. Our methodological results indicate that variation in archaeological sunflower achenes is better described by conventional size parameters rather than computerized shape analysis.     

Clovis in context: New light on the peopling of the Americas

Until recently, the first Americans were thought to be fluted-point spear-hunters from the Siberian steppes. Near the end of the Ice Age, they followed big-game herds over the Bering land bridge into the open, upland habitats of the interior of North America about 12,000 years ago. Rapidly extinguishing the big game herds with their deadly hunting methods, they pressed southward in search of new herds and reached the tip of South America about a thousand years later. Today, nearly 70 years after the first excavations at Clovis, New Mexico, the type site for this culture, new sites and new dates from both North and South America are forcing a revision of the earlier picture of the migrations and adaptations of the first Americans. But despite recurring claims that human colonization of the Western Hemisphere began as early as 20,000 or more years ago with the arrival of generalized foragers lacking a projectile-point tradition, no definitive data gives empirical support for a human presence before c. 12,000 before the present (B.P.). All supposed pre-Clovis cultures except one in Alaska have failed to withstand careful scrutiny of their data. In addition, despite recent claims for cultural and biological links of the migrants to Europe or the Pacific Islands, the skeletons and cultural assemblages of Paleoindians throughout the hemisphere point consistently to a northeast Asian origin. According to new data, Paleoindian ancestors in Beringia c. 12,000 years ago were not specialized, fluted-point hunters of large game, but broad-spectrum hunter-gatherers using triangular or bipointed, lanceolates. Diverse cultures descended from these ancestors, not only the big-game hunting Clovis culture of the North American high plains. And just as Clovis did not set the cultural pattern for the hemisphere, it was not the earliest culture. Fully contemporary with the earliest possible Clovis dates of c. 11,200, in South America there already were maritime foragers on the Pacific coast, small-game hunters in the southern pampas, and tropical forest riverine foragers in the eastern tropical lowlands. The Clovis culture thus was just one of several regional cultures developed in the millennium after the initial migration. It could not have been the ancestor of the other early Paleoindian cultures. This new picture of Paleoindian cultures changes understanding of initial human adaptive radiation in the Americas and has implications for general theories of human evolution and behavioral ecology.     

A Systematic Approach to Species–Level Identification of Chile Pepper (Capsicum spp.) Seeds: Establishing the Groundwork for Tracking the Domestication and Movement of Chile Peppers through the Americas and Beyond

A Systematic Approach to Species–Level Identification of Chile Pepper (Capsicum spp.) Seeds: Establishing the Groundwork for Tracking the Domestication and Movement of Chile Peppers through the Americas and Beyond The chile pepper (Capsicum spp.), a plant held in great esteem throughout history, was independently domesticated in a series of places including highland Bolivia, central Mexico, the Amazon, the Caribbean, and other locales with a particularly long history of cultivation and use in the central Andes of South America. Though identification of chile pepper species through fruit morphology is possible and has been utilized by botanists studying modern and archaeological specimens, species–level identification of Capsicum seeds has remained undetermined. Given the greater abundance of seed remains in the archaeological record due to the higher likelihood of preservation, the ability to identify specific Capsicum domesticates has profound implications for tracking the domestication and spread of chile peppers prehistorically through the Americas and historically through trade and exchange to the rest of the world. This article presents a systematic procedure to identify Capsicum seeds to the species level created by adopting a morphometric approach to compare attributes of modern Capsicum seeds to archaeological seeds.     

Biogeographic history of the butterfly subtribe Euptychiina (Lepidoptera,Nymphalidae, Satyrinae)

Peña, C., Nylin, S., Freitas, A. V. L. & Wahlberg, N. (2010). Biogeographic history of the butterfly subtribe Euptychiina (Lepidoptera, Nymphalidae, Satyrinae).—Zoologica Scripta, 39, 243–258. The diverse butterfly subtribe Euptychiina was thought to be restricted to the Americas. However, there is mounting evidence for the Oriental Palaeonympha opalina being part of Euptychiina and thus a disjunct distribution between it (in eastern Asia) and its sister taxon (in eastern North America). Such a disjunct distribution in both eastern Asia and eastern North America has never been reported for any butterfly taxon. We used 4447 bp of DNA sequences from one mitochondrial gene and four nuclear genes for 102 Euptychiina taxa to obtain a phylogenetic hypothesis of the subtribe, estimate dates of origin and diversification for major clades and perform a biogeographic analysis. Euptychiina originated 31 Ma in South America. Early Euptychiina dispersed from North to South America via the temporary connection known as GAARlandia during Eocene–Oligocene times. The current disjunct distribution of the Oriental Palaeonympha opalina is the result of a northbound dispersal of a lineage from South America into eastern Asia via North America. The common ancestor of Palaeonympha and its sister taxon Megisto inhabited the continuous forest belt across North Asia and North America, which was connected by Beringia. The closure of this connection caused the split between Palaeonympha and Megisto around 13 Ma and the severe extinctions in western North America because of the climatic changes of the Late Miocene (from 13.5 Ma onwards) resulted in the classic ‘eastern Asia and eastern North America’ disjunct distribution.     

Quinua and Relatives (Chenopodium sect.Chenopodium subsect.Celluloid)

Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.     

THE ORIGIN AND EVOLUTIONARY RELATIONSHIPS OF ‘HUAUZONTLE’ (CHENOPODIUM NUTTALLIAE SAFFORD), DOMESTICATED CHENOPOD OF MEXICO

A New World assemblage of tetraploid Chenopodium species (section Chenopodium, subsection Cellulata) includes two domesticates, C. quinoa of Andean South America and C. nuttalliae of Mexico. Both have been combined into a single species and the Mexican form has been considered as a possible derivative of C. quinoa. The domesticates and related, sympatric weed forms, C. berlandieri of North America and C. hircinum of the Andes, were examined for variation in morphological and biochemical characteristics and also were included in a program of artificial hybridization. Results indicate that the domesticated forms are more closely related to their sympatric weeds than to each other. The Mexican cultigen is placed as a subspecies of C. berlandieri, the taxon from which it most likely evolved under human selection in North America. Possible origins for the Andean weed-crop complex are considered. Southward migration of a North American tetraploid appears to be more likely than independent allotetraploidy in South America. Of the North American tetraploids examined, C. berlandieri var. zschackei of the western U.S. shows closest affinities to the Andean complex.     

Dissemination pathways of common bean (Phaseolus vulgaris,Fabaceae) deduced from phaseolin electrophoretic variability. I. The Americas

Dissemination pathways of common bean (Phaseolus vulgaris) cultivars from their areas of domestication to other parts of the Americas were determined using phaseolin type, as determined by 1-dimensional SDS/PAGE. Common bean cultivars of lowland South America exhibited approximately equal numbers of ‘S’ and ‘T’ phaseolin types. ‘S2019 cultivars of that region may have been introduced along a route starting in Middle America and leading into Colombia, Venezuela, and eventually Brazil. ‘T’ phaseolin cultivars in lowland South America may have been introduced directly from the Andes or indirectly by European immigrants. In the southwestern U.S.A., most of the cultivars showed an ‘S’ phaseolin, confirming the Middle American origin of these cultivars, as suggested previously by the archaeological record. In northeastern U.S.A. and Canada, the ‘T’and ‘C’ phaseolin types were more frequent than the ‘S’ phaseolin cultivars. While most of the former were possibly introduced into that region by European immigrants, most of the latter may have been introduced by the pre-Columbian Indian populations. Seed size analysis revealed that ‘T’ or ‘C’ phaseolin cultivars had significantly larger seeds than ‘S’ phaseolin cultivars, as had been observed previously in Middle America and the Andes. The phaseolin types of commercial seed types and of early northeastern U.S. cultivars are discussed.     

The domestication of Helianthus annuus L. (sunflower)

All modern domesticated sunflowers can be traced to a single center of domestication in the interior mid-latitudes of eastern North America. The sunflower achenes and kernels recovered from six eastern North American sites predating 3000 b.p. that document the early history of this important crop plant are reanalyzed, and two major difficulties in the interpretation of archaeological sunflower specimens are addressed. First, achenes and kernels obtained from a modern wild sunflower population included in a prior genetic study because of its minimal likelihood for crop-wild gene flow, and its close genetic relationship to domesticated sunflowers, provide a new and more tightly drawn basis of comparison for distinguishing between wild and domesticated achene and kernel specimens recovered from archaeological contexts. Second, achenes and kernels from this modern wild baseline population were carbonized, allowing a direct comparison between carbonized archaeological specimens and a carbonized modern wild reference class, thereby avoiding the need for the various problematic shrinkage correction conversion formulas that have been employed over the past half century. The need for further research on museum collections is underscored, and new research directions are identified.     

Preferential parental investment in daughters over sons

Female-biased parental investment is unusual but not unknown in human societies. Relevant explanatory models include Fisher’s principle, the Trivers-Willard model, local mate and resource competition and enhancement, and economic rational actor models. Possible evidence of female-biased parental investment includes sex ratios, mortality rates, parents’ stated preferences for offspring of one sex, and direct and indirect measurements of actual parental behavior. Possible examples of female-biased parental investment include the Mukogodo of Kenya, the Ifalukese of Micronesia, the Cheyenne of North America, the Herero of southern Africa, the Kanjar of south Asia, the Mundugumor of New Guinea, contemporary North America, and historical Germany, Portugal, and the United States. Lee Cronk is Assistant Professor of Anthropology at Texas A&M University, College Station, Texas. His main research interests are in human behavioral ecology, reproductive strategies, and East African hunter-gatherers and pastoralists.     

A critical review of the protracted domestication model for Near-Eastern founder crops: linear regression, long-distance gene flow, archaeological, and archaeobotanical evidence

The recent review by Fuller et al. (2012a) in this journal is part of a series of papers maintaining that plant domestication in the Near East was a slow process lasting circa 4000?years and occurring independently in different locations across the Fertile Crescent. Their protracted domestication scenario is based entirely on linear regression derived from the percentage of domesticated plant remains at specific archaeological sites and the age of these sites themselves. This paper discusses why estimates like haldanes and darwins cannot be applied to the seven founder crops in the Near East (einkorn and emmer wheat, barley, peas, chickpeas, lentils, and bitter vetch). All of these crops are self-fertilizing plants and for this reason they do not fulfil the requirements for performing calculations of this kind. In addition, the percentage of domesticates at any site may be the result of factors other than those that affect the selection for domesticates growing in the surrounding area. These factors are unlikely to have been similar across prehistoric sites of habitation, societies, and millennia. The conclusion here is that single crop analyses are necessary rather than general reviews drawing on regression analyses based on erroneous assumptions. The fact that all seven of these founder crops are self-fertilizers should be incorporated into a comprehensive domestication scenario for the Near East, as self-fertilization naturally isolates domesticates from their wild progenitors.     

<Emphasis Type="Italic">Quinua</Emphasis> and Relatives (<Emphasis Type="Italic">Chenopodium</Emphasis> sect.<Emphasis Type="Italic">Chenopodium</Emphasis> subsect.<Emphasis Type="Italic">Celluloid</Emphasis>)

Traditionally viewed as an Andean grain crop,Chenopodium quinoa Willd. includes domesticated populations that are not Andean, and Andean populations that are not domesticated. Comparative analysis of leaf morphology and allozyme frequencies have demonstrated that Andean populations, both domesticated(quinua) and free-living(ajara), represent an exceptionally homogeneous unit that is well differentiated from allied domesticates of coastal Chile(quingua) and freeliving populations of the Argentine lowlands(C. hircinum). This pattern of relationships indicates that Andean populations represent a monophyletic crop/weed system that has possibly developed through cyclic differentiation (natural vs. human selection) and introgressive hybridization. Relative levels of variation suggest that this complex originated in the southern Andes, possibly from wild types allied withC. hircinum, with subsequent dispersal north to Colombia and south to the Chilean coast. Coastal populations were apparently isolated from post-dispersal differentiation and homogenization that occurred in the Andes. Other data point toward a center of origin in the northern Andes with secondary centers of genetic diversity subsequently developing in the southern Andes and the plains of Argentina. Comparative linkage of South American taxa, all tetraploid, with North American tetraploids of the subsection will eventually clarify this problem. While the possibility of a direct phyletic connection betweenC. quinoa and the Mexican domesticate(C. berlandieri subsp. nuttalliae,) cannot be excluded, available evidence indicates that the latter represents an autonomous lineage that is associated with the basal tetraploid, C. b. subsp.berlandieri, through var.sinuatum, whereas South American taxa show possible affinities to either var. zschackei or var.berlandieri. An extinct domesticate of eastern North America,C. b. subsp.jonesianum, represents either another instance of independent domestication, possibly from subsp. b. var.zschackei, or a northeastern outlier of subsp.nuttalliae.     

Brachiopod community paleoecology, paleobiogeography, and depositional topography of the Devonian Onondaga Limestone and correlative strata in eastern North America

The Emsian? through early Eifelian Onondaga Limestone of the Appalachian Basin was deposited in a topographic basin and on the carbonate platform which surrounded the basin on the west, north, and northeast. Onondaga strata thin from the platform into the basin. Two sedimentary cycles are present in the sub-Tioga Onondaga of eastern North America. The Edgecliff-Amherstburg represents an interval of transgression, in which epeiric seas spread over much of eastern North America. During the Nedrow-Lucas regression, the interior of the carbonate platform became restricted, resulting in the deposition of evaporites. The Moorehouse-Anderdon transgression continued through the deposition of the Tioga Bentonite, followed by the pre-Speeds-Dundee regression from the craton. Early Eifelian Appalachian Basin Onondaga brachiopod communities, arranged from nearshore to offshore, include the Atrypid-Megakozlowskiella, Atrypid-Levenea, Chonetid, Atlanticocoelia, Ambocoeliid, and Truncalosia Communities. The Onondaga-age Eastern Americas Realm is divided into the Appohimchi Province in the Appalachian Basin and the Michigan Basin-Hudson Bay Lowland Province in the Midwest. The provincial assignment of the James Bay region of Ontario is uncertain; the Eastern Townships of Quebec are near the boundaries both of the two provinces of the Eastern Americas Realm, and of the Eastern Americas Realm and the Old World Realm, the latter realm being probably in the Canadian Maritime Provinces.     

EMOTIONAL CLIMATES: RITUAL, SEASONALITY AND AFFECTIVE DISORDERS

This article discusses resemblances between the religious symbolism of the annual cycle in certain societies, and seasonally linked mood disorders (notably seasonal affective disorder, or SAD) in contemporary Europe and North America. Two conclusions are drawn: first, that the ritual and symbolism connected with seasonality in some societies may be partly motivated by neurophysiology; second, that SAD is a culture-bound syndrome limited to societies that generate disjunctions between 'social' and 'natural' time.     

New Archaeological Evidence for an Early Human Presence at Monte Verde,Chile

Questions surrounding the chronology, place, and character of the initial human colonization of the Americas are a long-standing focus of debate. Interdisciplinary debate continues over the timing of entry, the rapidity and direction of dispersion, the variety of human responses to diverse habitats, the criteria for evaluating the validity of early sites, and the differences and similarities between colonization in North and South America. Despite recent advances in our understanding of these issues, archaeology still faces challenges in defining interdisciplinary research problems, assessing the reliability of the data, and applying new interpretative models. As the debates and challenges continue, new studies take place and previous research reexamined. Here we discuss recent exploratory excavation at and interdisciplinary data from the Monte Verde area in Chile to further our understanding of the first peopling of the Americas. New evidence of stone artifacts, faunal remains, and burned areas suggests discrete horizons of ephemeral human activity in a sandur plain setting radiocarbon and luminescence dated between at least ~18,500 and 14,500 cal BP. Based on multiple lines of evidence, including sedimentary proxies and artifact analysis, we present the probable anthropogenic origins and wider implications of this evidence. In a non-glacial cold climate environment of the south-central Andes, which is challenging for human occupation and for the preservation of hunter-gatherer sites, these horizons provide insight into an earlier context of late Pleistocene human behavior in northern Patagonia.     

Ustilago maydis populations tracked maize through domestication and cultivation in the Americas

The domestication of crops and the development of agricultural societies not only brought about major changes in human interactions with the environment but also in plants' interactions with the diseases that challenge them. We evaluated the impact of the domestication of maize from teosinte and the widespread cultivation of maize on the historical demography of Ustilago maydis, a fungal pathogen of maize. To determine the evolutionary response of the pathogen's populations, we obtained multilocus genotypes for 1088 U. maydis diploid individuals from two teosinte subspecies in Mexico and from maize in Mexico and throughout the Americas. Results identified five major U. maydis populations: two in Mexico; two in South America; and one in the United States. The two populations in Mexico diverged from the other populations at times comparable to those for the domestication of maize at 6000-10000 years before present. Maize domestication and agriculture enforced sweeping changes in U. maydis populations such that the standing variation in extant pathogen populations reflects evolution only since the time of the crop's domestication.     

Temporal and Spatial Distribution of Enterobius vermicularis (Nematoda: Oxyuridae) in the Prehistoric Americas

Investigations of Enterobius sp. infection in prehistory have produced a body of data that can be used to evaluate the geographic distribution of infection through time in the Americas. Regional variations in prevalence are evident. In North America, 119 pinworm positive samples were found in 1,112 samples from 28 sites with a prevalence of 10.7%. Almost all of the positive samples came from agricultural sites. From Brazil, 0 pinworm positive samples were found in 325 samples from 7 sites. For the Andes region, 22 pinworm positive samples were found in 411 samples from 26 sites for a prevalence of 5.3%. Detailed analyses of these data defined several trends. First, preagricultural sites less frequently show evidence of infection compared to agricultural populations. This is especially clear in the data from North America, but is also evident in the data from South America. Second, there is an apparent relationship between the commonality of pinworms in coprolites and the manner of constructing villages. These analyses show that ancient parasitism has substantial value in documenting the range of human behaviors that influence parasitic infections.     

Contradictions and Concordances in American Colonization Models

The traditional view of American colonization during the late Pleistocene has largely been conditioned on early conceptions of the timing and extent of continental glaciations and the age and distribution of archeological sites. A review of newer, high resolution genetic data, both from modern populations and ancient DNA samples, along with the emergence of several early archeological sites in both North and South America, and reconsiderations of the glacial dynamics in North America indicate that some aspects of the traditional view need reconsideration. It seems obvious from archeological data that a preglacial occupation of the Americas needs to be closely examined. Accumulating molecular genetic data raises new questions about the timing and population size of the initial colonization(s), while a closer examination of glacial models suggests that a number of routes into the Americas may have been available until fairly late in the last glacial cycle.     

Phylogeny and biogeography of Aralia sect. Aralia (Araliaceae)

Aralia sect. Aralia (Araliaceae) consists of approximately eight species disjunctly distributed in Asia and North America. Phylogenetic and biogeographic analyses were conducted using sequences of the internal transcribed spacer regions of the nuclear ribosomal DNA. Aralia racemosa from eastern North America was sister to A. californica from western North America. Aralia cordata from eastern Asia did not form a species-pair relationship with the eastern North American A. racemosa. The two subspecies of A. racemosa formed a monophyletic group. Biogeographic analyses showed a close area relationship between eastern North America and western North America. The Himalayas were cladistically basal and eastern Asia was placed between the Himalayas and North America. The biogeographic analysis supported the origin of the eastern Asian and eastern North American disjunct pattern in Aralia sect. Aralia via the Bering land bridges. Comparisons with results of phylogenetic analyses of other genera suggested that (1) the floristic connection between eastern North America and western North America may be stronger than previously thought; and (2) the biogeographic patterns in the Northern Hemisphere are complex. Furthermore, a lack of correlation between sequence divergence values and phylogenetic positions was observed, suggesting the importance of a phylogenetic framework in biogeographic analyses.     

Habitual cave use and thermoregulation in chacma baboons (Papio hamadryas ursinus)

The willingness to utilise caves as shelters is held to have been important to early humans but dependent on pyrotechnology. Despite anecdotal evidence that non-human primates will also exploit caves there has as yet been no detailed account of such exploitation or of the reasons underlying it. Here we provide the first such data, on the frequency and patterning of the use of an underground cave system by baboons (Papio hamadryas)—and show that usage is determined, at least in part, by above-ground temperatures.