Our current period in history has been called by many ..
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Energy and the Human Journey: Where We Have Been; …
About 1000 BCE, one of the largest migrations in the human journey, the , began, and it expanded because of the Bantus' use of iron and agriculture, and they displaced or absorbed hunter-gatherers as they expanded across sub-Saharan Africa. In a dynamic too common in human history, ; studies provide evidence of this.
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The most-accepted hypothesis today is that evolved from and first appeared in East Africa between 2.0 and 1.8 mya. If those are not the exact species that the human line descended through during those times, our actual ancestors were close cousins. The early adults had brains of about 850 ccs, and some later specimens reached 1,100 ccs, or triple the mass of a chimpanzee’s brain. Today’s human brain only averages about 1,200 ccs (). , as with other members of the line, had a brain that was another third larger than , and probably was responsible for its relatively sophisticated material culture. But important as its growing brain was, other anatomical changes were more telling. was fully adapted for living on the ground and walking great distances. For the first quarter-million years of existence, it lived in the Oldowan culture, which used tools and weapons that were little more than rocks with sharpened edges, and probably some shaped sticks. They evolved in a highly dangerous environment and all of their ancestors slept in trees. How could they have slept on the ground? In a word: fire.
Geologic time scale - Wikipedia
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No historian has argued that England had a grand plan of industrialization, but the Epochal Event was the culmination of several trends. Although the science of energy had yet to be invented, the obvious advantages of watermills, windmills, and sailing ships were not lost on people, and the control of arable land, forests, low-energy transportation lanes, workforces, and markets was always the road to riches from onward. People knew what they were doing, even if they had little or no long-term perspective.
Serfdom largely replaced slavery in Europe by about 1000, but . By 1434, the first captured Africans to use as slaves were delivered to . The sitting pope , and one of humanity’s greatest disasters began. Portugal dominated the for more than three centuries. The other Portuguese commercial obsession, before they seized the , , was gold. African gold began pouring into Lisbon when the slaves did, and the Portuguese began minting gold coins in 1452. The pursuit of slaves and gold characterized Portuguese and Spanish efforts in the Western Hemisphere during the 16th century, which caused history’s greatest demographic catastrophe: . Life was also cheap in the imperial nations. The mortality rate for the crew during the centuries that Portugal used its spice route . , and Europe ignored the cures for centuries.
A guide to prehistoric plants - Eden Project, Cornwall
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By the 1850s, Germany was , and seminal discoveries and achievements came from German labs. As agriculture became industrialized, two nutrients were identified as key limiting resources as per : phosphorous and . Until 1909, humanity’s source of nitrogen for agriculture was manure. Guano was even the main source of nitrate for gunpowder when World War I began in 1914. After a century of failure by many eminent chemists, in 1909 made one of history’s most momentous breakthroughs when he . That energy-intensive process is responsible for half of humanity’s food supply today. It is also partly responsible for a great deal of water pollution, , and proliferation of weaponry. Haber has also been called the father of chemical warfare, as he was instrumental in , but he nevertheless won his Nobel Prize in 1918 for his nitrogen breakthrough. Phosphorus, which forms the , is the sole element that humanity has not found a substitute for in industrial civilization. Energy makes nitrogen and other elements more available or allows for substitution, while phosphorous must be mined or recycled. German chemical wizardry continued after World War I, and Germany was the center of science in the early 20th century. Relativity and quantum theory, the two pillars of today’s physics, were developed in Germanic nations, and Einstein, , , , , , and dominated physics in the early 20th century, with relatively minor contributions from American, British, and French scientists. From the first Nobel prizes awarded in 1901 to the rise of Nazi Germany in 1933, more than a third of the awards in and went to Germans, and if the Swiss, Dutch, Austrian, Danish, and Swedish laureates are added, they amount to well more than half, particularly for their theoretical work.
The USA’s Civil War was not only a watershed event in American history, but it also became a pivotal event in world history. It marked the transition from a largely rural nation, , to quickly becoming an industrial juggernaut that Earth had never before witnessed, with consequences both salubrious and catastrophic. The final chapters of the USA's imperial history have yet to be written. With the Civil War, the . What I call phase two of the Industrial Revolution began, and the rise of oil and electricity dramatically transformed industrial civilization.
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Prehistoric Cultures by Sanderson Beck
what we can learn from this long period of evolution and ..
was used by the pre-historic cave painters of the Lascaux region ..
Photosynthesis; Las Posadas; ..
The earliest art objects in Europe also date from this period
Around when Harland first proposed a global ice age, a climate model developed by Russian climatologist concluded that if a Snowball Earth really happened, the runaway positive feedbacks would ensure that the planet would never thaw and become a permanent block of ice. For the next generation, that climate model made a Snowball Earth scenario seem impossible. In 1992, a professor, , that coined the term Snowball Earth. Kirschvink sketched a scenario in which the supercontinent near the equator reflected sunlight, as compared to tropical oceans that absorb it. Once the global temperature decline due to reflected sunlight began to grow polar ice, the ice would reflect even more sunlight and Earth’s surface would become even cooler. This could produce a runaway effect in which the ice sheets grew into the tropics and buried the supercontinent in ice. Kirschvink also proposed that the situation could become unstable. As the sea ice crept toward the equator, it would kill off all photosynthetic life and a buried supercontinent would no longer engage in . Those were two key ways that carbon was removed from the atmosphere in the day's , especially before the rise of land plants. Volcanism would have been the main way that carbon dioxide was introduced to the atmosphere (animal respiration also releases carbon dioxide, but this was before the eon of animals), and with two key dynamics for removing it suppressed by the ice, carbon dioxide would have increased in the atmosphere. The resultant greenhouse effect would have eventually melted the ice and runaway effects would have quickly turned Earth from an icehouse into a greenhouse. Kirschvink proposed the idea that Earth could vacillate between states.
the most outstanding displays of prehistoric art yet discovered.
During that “,” , , and the rise of grazing and predation had eonic significance. While many critical events in life’s history were unique, one that is not is multicellularity, , and some prokaryotes have multicellular structures, some even with specialized organisms forming colonies. There are , but the primary advantage was size, which would become important in the coming eon of complex life. The rise of complex life might have happened faster than the billion years or so after the basic foundation was set (the complex cell, oxygenic photosynthesis), but geophysical and geochemical processes had their impacts. Perhaps most importantly, the oceans probably did not get oxygenated until just before complex life appeared, as they were sulfidic from 1.8 bya to 700 mya. Atmospheric oxygen is currently thought to have remained at only a few percent at most until about 850 mya, although there are recent arguments that it remained low until only about 420 mya, when large animals began to appear and animals began to colonize land. Just as the atmospheric oxygen content began to rise, then came the biggest ice age in Earth’s history, which probably played a major role in the rise of complex life.
study of prehistoric plants | EUdict | English>English
Kirschvink noted that reappeared in the geological record during the possible Snowball Earth times, after vanishing about a billion years earlier. Kirschvink noted that iron cannot increase to levels where they would create BIFs if the global ocean was oxygenated. Kirschvink proposed that the sea ice not only killed the photosynthesizers, but it also separated the ocean from the atmosphere so that the global ocean became anoxic. Iron from volcanoes on the ocean floor would build up in solution during the , and during the greenhouse phase the oceans would become oxygenated and the iron would fall out in BIFs. Other geological evidence for the vacillating icehouse and greenhouse conditions was the formation of cap carbonates over the glacial till. It was a global phenomenon; wherever the Snowball Earth till was, cap carbonates were atop them. In geological circles, deposited during the past 100 million years are considered to be of tropical origin, so scientists think that the cap carbonates reflected a tropical environment. The fact of cap carbonates atop glacial till is one of the strongest pieces of evidence for the Snowball Earth hypothesis. Kirschvink finished his paper by noting that the eon of complex life came on the heels of the Snowball Earth, and scouring the oceans of life would have presented virgin oceans for the rapid spread of life in the greenhouse periods, and this could have initiated the evolutionary novelty that led to complex life.
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