Video Experimental Relacionado
Updated: Jul 12, 2026
07:55
Preparation of Hard Palm Seeds for Matrix-Assisted Laser Desorption/Ionization-Imaging Mass Spectrometry Analysis
Published on: June 30, 2023
Cerámica del octavo milenio de una concha prehistórica en el Amazonas brasileño
Science (New York, N.Y.)
|December 13, 1991
Resumen
La cerámica más antigua en el hemisferio occidental, que data de hace 8.000 años, se encontró en Brasil. Este descubrimiento desafía las teorías de que los entornos tropicales limitaban el desarrollo cultural humano temprano.
Área de la Ciencia:
- Arqueología Arqueología.
- La Antropología Antropología Antropología.
Sus antecedentes:
- La prehistoria de la cuenca del Amazonas es crucial para comprender la migración humana temprana y el desarrollo cultural.
- Las teorías anteriores sugerían que las limitaciones de recursos en las regiones tropicales obstaculizaban las sociedades complejas.
Objetivo del estudio:
- Para investigar los orígenes de la cerámica en el hemisferio occidental.
- Desafiar los modelos existentes de evolución cultural en entornos tropicales.
Principales métodos:
- Excavación de una concha prehistórica en el centro cerca de Santarém, Brasil.
- Datación por radiocarbono con acelerador calibrado de carbón vegetal, conchas y cerámica.
- La datación por termoluminiscencia de la cerámica.
Principales resultados:
- Descubrimiento de la cerámica más antigua en el hemisferio occidental.
- Datando la cerámica y los materiales del sitio asociados entre 8.000 y 7.000 años antes del presente.
- La evidencia de un pueblo pesquero desarrollado es anterior a los plazos establecidos.
Conclusiones:
- Los hallazgos retrasan significativamente la línea de tiempo de la cerámica en las Américas.
- La complejidad de los primeros pueblos pesqueros amazónicos contradice las teorías del estancamiento cultural debido a la pobreza de los recursos tropicales.
Más Videos Relacionados
07:00Microbiota of Attine Ants' Gardens: Visualizing a Microbial Landscape by Scanning Electron Microscopy
Published on: October 4, 2024
09:06Removal of Exogenous Materials from the Outer Portion of Frozen Cores to Investigate the Ancient Biological Communities Harbored Inside
Published on: July 3, 2016
Videos de Conceptos Relacionados
02:56The Fossil Record
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:24Freshwater Microbial Ecology
Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
02:31Habitat Fragmentation
Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land conversion, as well as slower geological processes leading to changes in the physical environment, are the two leading causes of habitat fragmentation. The fragmentation process typically follows the same steps: perforation, dissection, fragmentation, shrinkage, and attrition.
01:18Porosity in Cement Paste
The porosity of concrete is a measure of the void spaces within its structure. These spaces impact its strength and durability significantly. When water and cement interact, a chemical reaction called hydration creates a semi-solid paste. This paste includes combined water, making up approximately 23% of the cement's dry mass, and gel water, which fills minuscule voids known as gel pores, accounting for about 28% of the cement gel volume.
The balance of water to cement in the mix is critical—it...
The balance of water to cement in the mix is critical—it...