Tropical nature and other essays U c essays

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.

Wallace tropical nature and other essays My aha moment essay

Tropical plants and animals are those species native to the tropics

Free tsunami Essays and Papers - Free Essays, Term …

Economics is the study of humanity’s material well-being, but humans have rarely thought past their immediate economic self-interest, even when the long-term prospects were obviously suicidal, such as today’s global energy paradigm. Because environmental issues affect humanity’s material well-being, they are economic in nature. As can be seen so far in this essay, there was little awareness or seeming caring in early civilizations whether they were destroying the very foundations of their civilizations. Even if they did not care how much other life forms suffered, they did not seem to realize that it also meant that those oppressed and exterminated organisms and wrecked environments would not provide much benefit to humanity in the future, especially energy, whether it was food or wood.

Free tsunami papers, essays, and research papers

The first five books of the Bible, called the , are considered by today’s scholars to have been a political tract written centuries after the alleged events occurred. It was like the taught to today’s schoolchildren as a way to cultivate blind obedience to the state. Early Israel and Judah were tiny kingdoms in the hills, sandwiched between Assyria and Egypt, which were warring regional powers. Israel was destroyed about 722 BCE after the Israeli king defied the Assyrian king, and ten of Israel’s tribes were forcibly relocated by Assyria and became lost to history. The Assyrians forcibly relocated more than four million people. Those “lost tribes” became the focus of for millennia. Writing the Pentateuch was an understandable effort to help Israelites survive, as a kind of nationalistic parable. The New Testament and Koran were also written long after the alleged events, accompanied by huge political battles over what the official story would be. Whatever divine inspiration Jesus may have had access to, ("" (AKA "") is perhaps the most enlightened message ever given to humanity), or other figures in Judeo-Christian or Islamic tales, what certain is that priesthoods and rulers shamelessly distorted them to serve their agendas of amassing and maintaining wealth and power, in a pattern that and lasts to this day.

These results are sorted by most relevant first (ranked search)
She is both beautiful and cowardly

George Orwell: Notes on Nationalism

In light of depiction of low Mesozoic oxygen levels, Peter Ward addressed a controversial issue regarding how dinosaurs breathed. Birds have an air sac breathing system with an inflexible septate lung, which is highly superior to the mammalian . At 1600 meters elevation, today’s birds are about twice as efficient at extracting atmospheric oxygen as mammals are. Flying is the most aerobically demanding activity on Earth and a bird’s air-sac breathing system is a primary reason why they can fly, and is an energetic feat far beyond what any mammal can accomplish. The high-performance respiration that birds possess is also why they live far longer than similarly sized mammals, but is . When a mammal breathes, it inhales oxygenated air and exhales carbon dioxide, but it is not a very efficient system, as fresh and depleted air mix in the lungs. The , on the other hand, passes fresh oxygenated air along the lungs with each breath. One might say that birds constantly inhale. can . Since birds evolved from dinosaurs, and indeed dinosaurs, just when this innovation developed is of great interest to paleobiologists. If the early Mesozoic were the low-oxygen times that GEOCARBSULF depicts, then the air sac system would have been a logical adaptation to oxygen-poor air.

Planetary boundaries - Wikipedia

Free tsunami Essays and Papers - 123HelpMe

Other than humans, rhesus macaques are Earth’s most widespread primates, and both species are generalists whose ability to adapt has been responsible for their success. Rhesus macaques are , about twice that of dogs and cats, and nearly as much as chimpanzees. Rhesus macaques have what is called Machiavellian social organization, in which everybody is continually vying for rank and power is everything. Those with rhesus power get the most and best food, the best and safest sleeping places, mating privileges, the nicest environments to live in, and endless grooming by subordinates, whom the dominants can beat and harass whenever they want, while those low in the hierarchies get the scraps and are usually the first to succumb to the vagaries of rhesus life, including predation. It is the . But even the lowliest macaque will become patriotic cannon fodder if his society faces an external threat, as even a macaque knows that a miserable life is better than no life at all. The violence inflicted seems economically optimized; within a society the violence is mostly harassment, but when rival societies first come in contact, the violence is often lethal, as the initially established dominance can last for lifetimes. Within a society, killing a subordinate does not make economic sense, as that subordinate supports the hierarchy. Potentates rely on slaves. The human smile evolved from the teeth-baring display of monkeys that connotes fear or submission.

Which definition, what one?: Which of these do you want? Which do you want? See more.

Essays on American environmental history

works for animals that are no more than a couple of millimeters thick, but for larger animals a respiration system was necessary. The rise of the arthropods has been an enduring problem for paleobiologists. Why was the arthropod so successful, particularly in the beginning? Segmented animals dominated Cambrian seas, and segmentation provides for repeated features. Segments obviously became important for locomotion but, for arthropods, segmentation appears to have conferred the more important advantage of distributed oxygen absorption. Each trilobite leg had an attached gill, and leg motion constantly drew fresh oxygenated water over each gill. Arthropods never developed the kinds of lungs that vertebrates have, or the pump gills of fish and other aquatic animals. Early arthropods breathed by moving their legs. Peter Ward’s recent hypothesis is that segments were first used for respiration, to provide a large gill surface area, and using the segments for locomotion came later. For trilobites, the same functionality that pushed water over gills was also coopted for food intake. Also, the leg-mounted gill was necessary because of an arthropod’s body armor; oxygen could not be absorbed through tough exoskeletons.