The cultural heritage shapes the pattern of tumour profiles in Europe: a correlation study. (1/209)

STUDY OBJECTIVE: This study investigates the spatial pattern of tumours in Europe to check the feasibility of a large scale ecological epidemiology approach to cancer in Europe. SETTING: The tumour types relative frequencies and cancer incidence (for men and women) reported in the European cancer registries were investigated by exploratory data analysis techniques. Socioeconomical descriptors of the female condition were considered as well. MAIN RESULTS: The classification of the European regional areas covered by the cancer registries followed almost exactly the boundaries set by the long and intermingled European history in terms of life styles and cultural heritage. This result supports the notion of a predominant role of environmental factors in cancer induction. Further support to the above result was given by the finding of a correlation between differential male-female cancer incidence, and socioeconomic descriptors of the female condition. CONCLUSIONS: From a methodological point of view, the consistency of these results pointed to the feasibility of an ecological approach to tumour epidemiology.  (+info)

The mimetic transition: a simulation study of the evolution of learning by imitation. (2/209)

Culturally transmitted ideas or memes must have had a large effect on the survival and fecundity of early humans. Those with better techniques of obtaining food and making tools, clothing and shelters would have had a substantial advantage. It has been proposed that memes can explain why our species has an unusually large brain and high cognitive ability: the brain evolved because of selection for the ability to imitate. This article presents an evolutionary model of a population in which culturally transmitted memes can have both positive and negative effects on the fitness of individuals. It is found that genes for increased imitative ability are selectively favoured. The model predicts that imitative ability increases slowly until a mimetic transition occurs where memes become able to spread like an epidemic. At this point there is a dramatic increase in the imitative ability, the number of memes known per individual and the mean fitness of the population. Selection for increased imitative ability is able to overcome substantial selection against increased brain size in some cases.  (+info)

Genetic evidence for different male and female roles during cultural transitions in the British Isles. (3/209)

Human history is punctuated by periods of rapid cultural change. Although archeologists have developed a range of models to describe cultural transitions, in most real examples we do not know whether the processes involved the movement of people or the movement of culture only. With a series of relatively well defined cultural transitions, the British Isles present an ideal opportunity to assess the demographic context of cultural change. Important transitions after the first Paleolithic settlements include the Neolithic, the development of Iron Age cultures, and various historical invasions from continental Europe. Here we show that patterns of Y-chromosome variation indicate that the Neolithic and Iron Age transitions in the British Isles occurred without large-scale male movements. The more recent invasions from Scandinavia, on the other hand, appear to have left a significant paternal genetic legacy. In contrast, patterns of mtDNA and X-chromosome variation indicate that one or more of these pre-Anglo-Saxon cultural revolutions had a major effect on the maternal genetic heritage of the British Isles.  (+info)

Solar forcing of drought frequency in the Maya lowlands. (4/209)

We analyzed lake-sediment cores from the Yucatan Peninsula, Mexico, to reconstruct the climate history of the region over the past 2600 years. Time series analysis of sediment proxies, which are sensitive to the changing ratio of evaporation to precipitation (oxygen isotopes and gypsum precipitation), reveal a recurrent pattern of drought with a dominant periodicity of 208 years. This cycle is similar to the documented 206-year period in records of cosmogenic nuclide production (carbon-14 and beryllium-10) that is thought to reflect variations in solar activity. We conclude that a significant component of century-scale variability in Yucatan droughts is explained by solar forcing. Furthermore, some of the maxima in the 208-year drought cycle correspond with discontinuities in Maya cultural evolution, suggesting that the Maya were affected by these bicentennial oscillations in precipitation.  (+info)

Prehistoric human colonization of India. (5/209)

Human colonization in India encompasses a span of at least half-a-million years and is divided into two broad periods, namely the prehistoric (before the emergence of writing) and the historic (after writing). The prehistoric period is divided into stone, bronze and iron ages. The stone age is further divided into palaeolithic, mesolithic and neolithic periods. As the name suggests, the technology in these periods was primarily based on stone. Economically, the palaeolithic and mesolithic periods represented a nomadic, hunting-gathering way of life, while the neolithic period represented a settled, food-producing way of life. Subsequently copper was introduced as a new material and this period was designated as the chalcolithic period. The invention of agriculture, which took place about 8000 years ago, brought about dramatic changes in the economy, technology and demography of human societies. Human habitat in the hunting-gathering stage was essentially on hilly, rocky and forested regions, which had ample wild plant and animal food resources. The introduction of agriculture saw it shifting to the alluvial plains which had fertile soil and perennial availability of water. Hills and forests, which had so far been areas of attraction, now turned into areas of isolation. Agriculture led to the emergence of villages and towns and brought with it the division of society into occupational groups. The first urbanization took place during the bronze age in the arid and semi-arid region of northwest India in the valleys of the Indus and the Saraswati rivers, the latter represented by the now dry Ghaggar-Hakra bed. This urbanization is known as the Indus or Harappan civilization which flourished during 3500-1500 B.C. The rest of India during this period was inhabited by neolithic and chalcolithic farmers and mesolithic hunter-gatherers. With the introduction of iron technology about 3000 years ago, the focus of development shifted eastward into the Indo-Gangetic divide and the Ganga valley. The location of the Mahabharata epic, which is set in the beginning of the first millennium B.C., is the Indo-Gangetic divide and the upper Ganga-Yamuna doab (land between two rivers). Iron technology enabled pioneering farmers to clear the dense and tangled forests of the middle and lower Ganga plains. The focus of development now shifted further eastward to eastern Uttar Pradesh and western Bihar which witnessed the events of the Ramayana epic and rise of the first political entities known as Mahajanapadas as also of Buddhism and Jainism. The second phase of urbanization of India, marked by trade, coinage, script and birth of the first Indian empire, namely Magadha, with its capital at Pataliputra (modern Patna) also took place in this region in the sixth century B.C. The imposition by Brahmin priests of the concepts of racial and ritual purity, pollution, restrictions on sharing of food, endogamy, anuloma (male of upper caste eligible to marry a female of lower caste) and pratiloma (female of upper caste ineligible to marry a male of lower caste) forms of marriage, karma (reaping the fruits of the actions of previous life in the present life), rebirth, varnashrama dharma (four stages of the expected hundred-year life span) and the sixteen sanskaras (ceremonies) on traditional occupational groups led to the birth of the caste system - a unique Indian phenomenon. As a consequence of the expansion of agriculture and loss of forests and wildlife, stone age hunter-gatherers were forced to assimilate themselves into larger agriculture-based rural and urban societies. However, some of them resisted this new economic mode. To this day they have persisted with their atavistic lifestyle, but have had to supplement their resources by producing craft items or providing entertainment to the rural population.  (+info)

Major long-term factors influencing dental education in the twenty-first century. (6/209)

With evolutionary advances in oral science over the long term, clinical reliance on chemotherapeutics, bacterial replacement therapy, and immunization will necessitate a broader background in medicine. The dramatic increase in the old age population will also require a much stronger medical background. By 2050, those over fifty-five years of age will represent 56 percent of the population, and 25 percent of these will be sixty-five years of age and older. The merging of dental and medical education is predicted to occur within the twenty-first century. Other topics addressed include research activities, with recommended strategies to enhance the integration of scientific and clinical dental approaches; the problem of dental faculty isolation; and the implications of financial constraint and accountability.  (+info)

Orangutan cultures and the evolution of material culture. (7/209)

Geographic variation in some aspects of chimpanzee behavior has been interpreted as evidence for culture. Here we document similar geographic variation in orangutan behaviors. Moreover, as expected under a cultural interpretation, we find a correlation between geographic distance and cultural difference, a correlation between the abundance of opportunities for social learning and the size of the local cultural repertoire, and no effect of habitat on the content of culture. Hence, great-ape cultures exist, and may have done so for at least 14 million years.  (+info)

Vocal clans in sperm whales (Physeter macrocephalus). (8/209)

Cultural transmission may be a significant source of variation in the behaviour of whales and dolphins, especially as regards their vocal signals. We studied variation in the vocal output of 'codas' by sperm whale social groups. Codas are patterns of clicks used by female sperm whales in social circumstances. The coda repertoires of all known social units (n = 18, each consisting of about 11 females and immatures with long-term relationships) and 61 out of 64 groups (about two social units moving together for periods of days) that were recorded in the South Pacific and Caribbean between 1985 and 2000 can be reliably allocated into six acoustic 'clans', five in the Pacific and one in the Caribbean. Clans have ranges that span thousands of kilometres, are sympatric, contain many thousands of whales and most probably result from cultural transmission of vocal patterns. Units seem to form groups preferentially with other units of their own clan. We suggest that this is a rare example of sympatric cultural variation on an oceanic scale. Culture may thus be a more important determinant of sperm whale population structure than genes or geography, a finding that has major implications for our understanding of the species' behavioural and population biology.  (+info)