Video Experimental Relacionado
Updated: Aug 10, 2026
09:00
High Throughput Analysis of Liquid Droplet Impacts
Published on: March 6, 2020
Evidencia en contra de un importante evento de enfriamiento de las secas más jóvenes en Nueva Zelanda
1Research School of Earth Sciences, Victoria University, Post Office Box 600, Wellington, New Zealand.
Science (New York, N.Y.)
|August 7, 1998
Resumen
El Younger Dryas no causó una caída significativa de la temperatura en Nueva Zelanda, según los registros de polen. Los avances glaciales probablemente se debieron al aumento de las nevadas, no a temperaturas más frías, lo que respalda los modelos climáticos específicos del Dryas más joven.
Área de la Ciencia:
- Paleoclimatología Paleoclimatología
- Geología Cuaternaria Geología Cuaternaria
- Palinología Palinología.
Sus antecedentes:
- El Dryas más joven es un período frío significativo durante la última deglaciación.
- Comprender las respuestas climáticas regionales al Younger Dryas es crucial para el modelado climático.
- Investigaciones anteriores han debatido el alcance del enfriamiento del hemisferio sur durante este período.
Objetivo del estudio:
- Para investigar las condiciones climáticas en Nueva Zelanda durante el Younger Dryas.
- Para determinar si se produjo una disminución significativa de la temperatura en el hemisferio sur.
Principales métodos:
- Análisis de registros de polen de secuencias deglaciales en el noroeste de Nelson, Nueva Zelanda.
- Correlación de datos paleobotánicos con la evidencia geológica de la actividad glacial.
Principales resultados:
- Los datos de polen no indican una disminución significativa de la temperatura en Nueva Zelanda durante el Younger Dryas.
- Los avances de los glaciares en la región se atribuyen al aumento de las precipitaciones y la acumulación de nieve.
- Los hallazgos desafían la noción de un enfriamiento generalizado en el hemisferio sur.
Conclusiones:
- El Younger Dryas no impuso una disminución térmica significativa en Nueva Zelanda.
- Las dinámicas climáticas regionales, como los cambios en las precipitaciones, jugaron un papel más crítico que la temperatura.
- Los resultados apoyan los modelos climáticos de inicio de Younger Dryas que no requieren una mayor circulación occidental o enfriamiento del hemisferio sur.
Videos de Conceptos Relacionados
01:50Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
01:07Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
01:38Limits to Natural Selection
Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.For one, natural selection can only act upon existing genetic variation. Hypothetically, redtusks may enhance elephant survival by deterring ivory-seeking poachers. However, if there are no gene variants—or alleles—for redtusks, natural selection cannot increase the prevalence of...
02:06Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
02:55The Evidence for Evolution
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.
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...