Ideas previas en el alumnado de magisterio de educación primaria sobre el interior de la tierra

Objetivos del presente estudio: 1) identificar las ideas previas del alumnado de magisterio sobre el estructura interna de la Tierra, con especial énfasis en donde se genera el magma que da lugar a los fenómenos ígneos, tanto volcánicos como plutónicos, y que constituye uno de los eslabones fundamentales del ciclo de las rocas, y, por ende, de la dinámica del planeta en el que vivimos. 2) Plantear posibles estrategias de cara a la enseñanza-aprendizaje de los contenidos relacionados con la estructura interna de la Tierra y con la procedencia/residencia del magma que origina los procesos ígneos

Tracing the Origin and Spread of Agriculture in Europe

The origins of early farming and its spread to Europe have been the subject of major interest for some time. The main controversy today is over the nature of the Neolithic transition in Europe: the extent to which the spread was, for the most part, indigenous and animated by imitatio (cultural diffusion) or else was driven by an influx of dispersing populations (demic diffusion). We analyze the spatiotemporal dynamics of the transition using radiocarbon dates from 735 early Neolithic sites in Europe, the Near East, and Anatolia. We compute great-circle and shortest-path distances from each site to 35 possible agricultural centers of origin—ten are based on early sites in the Middle East and 25 are hypothetical locations set at 58 latitude/longitude intervals. We perform a linear fit of distance versus age (and vice versa) for each center. For certain centers, high correlation coefficients (R . 0.8) are obtained. This implies that a steady rate or speed is a good overall approximation for this historical development. The average rate of the Neolithic spread over Europe is 0.6–1.3 km/y (95% confidence interval). This is consistent with the prediction of demic diffusion(0.6–1.1 km/y). An interpolative map of correlation coefficients, obtained by using shortest-path distances, shows that the origins of agriculture were most likely to have occurred in the northern Levantine/Mesopotamian area