Científicos de la Universidad de Pittsburgh y del Museo de Ciencia de Buffalo han encontrado pruebas que los humanos estamos más cerca de los orangutanes que los chimpancés. Analizando los rasgos físicos de los primates vivos y de los fósiles de nuestros ancestros, el antropólogo Jeffrey H. Schwartz y sus colegas han llegado a la conclusión de que humanos y orangutanes pertenecen a un grupo separado de los chimpancés y los gorilas. En concreto, tras analizar casi un centenar de características fisiológicas han demostrado que el Homo sapiens comparte 28 rasgos únicos con los orangutanes (Pongo pygmaeus), y sólo 2 con los chimpancés y 7 con los gorilas. Además, el orangután también tiene muchos rasgos comunes con los Australopithecus, ancestro del hombre moderno. Y afirma que hace aproximadamente 12 millones de años éste migró de África a Asia (de donde es originario el orangután), cruzando los bosques que entonces se extendían por toda Europa.
Aparentemente los nuevos datos contradicen los análisis genéticos, que muestran grandes similitudes entre el genoma del ser humano y el del chimpancé. Y añade que es importante para la ciencia “cuestionarse” estos parentescos a la vista de las nuevas evidencias morfológicas.
World Environment Day (WED) is one of the principal vehicles through which the United Nations stimulates worldwide awareness of the environment and enhances political attention and action.
The agenda is to give a human face to environmental issues; empower people to become active agents of sustainable and equitable development; promote an understanding that communities are pivotal to changing attitudes towards environmental issues; and advocate partnership which will ensure all nations and peoples enjoy a safer and more prosperous future.
Nosotros no elegimos a la familia, pero sí a los amigos. Al menos eso creíamos hasta ahora. Durante los ultimos 10 años el sociólogo holandés Gerald Mollehorst ha hecho un estudio con 1.000 sujetos de edades comprendidas entre 18 y 65 años para intentar comprobar hasta qué punto tenemos el “control” nuestra red de contactos. Y ha llegado a la conclusión de que las elecciones personales a la hora de elegir amigos están muy limitadas por las escasas oportunidades de conocer nuevas personas.Además, según Mollenhorst sólo el 48% de nuestros amigos permanece con nosotros tramscurridos 7 años. Y sólo un 30% de nuestros amigos cercanos se mantiene en la misma posición de confianza y cercanía pasado los 7 años.
"You could hear women lamenting, children crying, men shouting. There were some so afraid of death that they prayed for death. Many raised their hands to the gods, and even more believed that there were no gods any longer and that this was one unending night for the world." —Pliny the Younger, circa A.D. 97 to 109
WHAT HAPPENED HERE
August 25, A.D. 79
It all lasted 19 hours.
Then, there was only a long, deathly silence. Pompeii lay buried for nearly 1,700 years. It wasn't until 1748 that archaeologists began slowly uncovering the ancient city, preserved under 9 feet of volcanic ash and frozen in time by Pliny the Younger's vivid report.
About three-fifths of the city has been liberated from the solidified volcanic ash and pumice that engulfed it. But many questions remained unanswered for a long time.
What was life like under the volcano? What exactly did happen that summer day in A.D. 79? Here we take a look into the latest findings.
WHY IS VESUVIUS LOCATED WHERE IT IS? GLOBAL PERSPECTIVE
Vesuvius is near a place where one section of the Earth's surface is being pushed down below another section. These sections are called plates. When plates grind against one another two things can result--earthquakes and volcanoes. Volcanoes begin to form when the rocks of the lower plate get pushed deep into the Earth. There they are heated, until they melt, forming magma, one kind of liquid rock. Because magma is less dense than the solid rock around it, it is pushed upward. If this magma finds a weak place at the Earth's surface, it may break through and form a volcano.
Subduction
WHAT KIND OF VOLCANO IS VESUVIUS? VOLCANO TYPES
Vesuvius is a stratovolcano (or composite volcano), made up of alternate layers of ash and lava. Stratovolcanoes normally have two different kinds of eruptions. One kind produces mostly ash and cinders. The other kind produces lava. In Vesuvius these two types of eruption have not been seen to happen together.
INSIDE A VOLCANO
This is a type of volcano called a stratovolcano. You can see how this very tall volcano has been built up by layers of ash and lava from previous eruptions. The volcano is currently dormant. But it is about to re-awaken!
Because it is lighter than solid rock, magma (molten rock) has been rising to form a huge pool, called a magma chamber, beneath the volcano. The volcano will erupt when gases held within the magma burst out explosively, now that they are under less pressure than when the magma was deeper within the earth.
The explosive escape of the gases from the magma causes a violent eruption which literally "blows the top" off the volcano. Gas, blobs of magma (now called lava), chunks of rock, and fine debris called volcanic ash are blasted upwards. (The ash, because it is very light, may reach heights sufficient to endanger jet airplanes.)
Because the fragments of rock and ash (pyroclastics) are heavier than air and may not mix with enough air to remain high aloft, they may surge down the sides of the volcano as dangerous "pyroclastic flows."
Within the flow, heavier particles sink and the lighter particles and gases are displaced upwards. The flow meanwhile surges along like a boiling cloud. Pyroclastic flows can travel at speeds greater than 100 miles per hour and can be as hot as the inside of a kiln. Such flows killed 29,000 people in the 1902 eruption of Mount Pelée, Martinique.
WOULD YOU SURVIVE?
The volcanic eruption of Mount Vesuvius in A.D. 79 caught most of the Roman population off guard. Would you have made it?
Sin duda esta animación que vimos el último día de clase os ayudará a entender mejor la estructura y el funcionamiento de nuestro amado planeta Tierra (el único que por ahora habitamos).
Bueno aquí os dejo un vídeo de un tsunami; mientras que un surfista estaba surfeando, le vienen olas gigantescas que se acercan a él, y al final del vídeo, se le pierde de vista y probablemente, muere. Espero que os guste:
Ya que el último vídeo de Volcanes que subí al Blog no fue bastante bueno, he encontrado otro más interesante y novedoso: Es un Documental que habla sobre los Tipos de Volcanes y su Comportamiento, de Discovery Channel. Espero que os guste:
