Personal Essay: Journey to Studying Pharmacy - About two years ..
The Triassic began hot and ended hot, and the Jurassic and Cretaceous were also hot, so staying warm was not a significant issue for dinosaurs. stayed cool by becoming aquatic, and for land-based dinosaurs, features such as plates apparently replaced the sails of for both heating and cooling, and like the synapsid sail, those plates may have also been used for display. Also, like the cliché, many large herbivorous dinosaurs lived near cooling swamps, although the issue has been controversial. Cooling swamps and protective water holes that we see in the tropics today were a major aspect of Mesozoic landscapes. But the thermoregulatory aspect that most work is directed toward today is how dinosaurs kept warm. There is compelling evidence that dinosaurs regulated their body temperature in myriad ways, including internal chemistry. All bipedal animals today are endotherms and they all have four-chambered hearts, as dinosaurs did. , dinosaurs living near the poles (, ), and of dinosaur bones all support the idea that , but one of the more intriguing areas is that of . Like tree rings, bones have seasonal growth rings and they have been read for many dinosaur fossils. They have been used to determine dinosaurian life expectancies. could live to be about 30, giant could live to be 50, and smaller dinosaurs, as with smaller mammals, lived shorter lives. The tiny ones only lived three-to-four years and the mid-sized ones lived seven-to-fifteen years. Growth rates also provide thermoregulation evidence. Tyrannosaurs had juvenile growth spurts and largely stopped growing as adults, and sauropods had growth rates equivalent to today’s whales, which are Earth’s fastest growing animals. But there is also evidence of ectothermic dynamics. The great size of dinosaurs would have led to relatively easy ways to stay warm, as large animals have a greater mass-to-surface area ratio, like the way in which . Also, in the generally hot Mesozoic times, staying warm would have been fairly easy, particularly for huge dinosaurs.
This essay discusses the journey of my life
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.
Creative Essay My Journey Nicholas A
The ecosystems may not have recovered from Olson’s Extinction of 270 mya, and at 260 mya came another mass extinction that is called the mid-Permian or extinction, or the , although a recent study found only one extinction event, in the mid-Capitanian. In the 1990s, the extinction was thought to result from falling sea levels. But the first of the two huge volcanic events coincided with the event, in . There can be several deadly outcomes of major volcanic events. As with an , massive volcanic events can block sunlight with the ash and create wintry conditions in the middle of summer. That alone can cause catastrophic conditions for life, but that is only one potential outcome of volcanism. What probably had far greater impact were the gases belched into the air. As oxygen levels crashed in the late Permian, there was also a huge carbon dioxide spike, as shown by , and the late-Permian volcanism is the near-unanimous choice as the primary reason. That would have helped create super-greenhouse conditions that perhaps came right on the heels of the volcanic winter. Not only would carbon dioxide vent from the mantle, as with all volcanism, but the late-Permian volcanism occurred beneath Ediacaran and Cambrian hydrocarbon deposits, which burned them and spewed even more carbon dioxide into the atmosphere. Not only that, great salt deposits from the Cambrian Period were also burned via the volcanism, which created hydrochloric acid clouds. Volcanoes also spew sulfur, which reacts with oxygen and water to form . The oceans around the volcanoes would have become acidic, and that fire-and-brimstone brew would have also showered the land. Not only that, but the warming initiated by the initial carbon dioxide spike could have then warmed up the oceans enough so that methane hydrates were liberated and create even more global warming. Such global warming apparently warmed the poles, which not only melted away the last ice caps and ended an ice age that had , but deciduous forests are in evidence at high latitudes. A 100-million-year Icehouse Earth period ended and a 200-million-year Greenhouse Earth period began, but the transition appears to have been chaotic, with wild swings in greenhouse gas levels and global temperatures. Warming the poles would have lessened the heat differential between the equator and poles and further diminished the lazy Panthalassic currents. The landlocked Paleo-Tethys and Tethys oceans, and perhaps even the Panthalassic Ocean, may have all become superheated and anoxic as the currents died. Huge also happened, which may have and led to ultraviolet light damage to land plants and animals. That was all on top of the oxygen crash. With the current state of research, all of the above events may have happened, in the greatest confluence of life-hostile conditions during the eon of complex life. A recent study suggests that the extinction event that ended the Permian may have lasted only 60,000 years or so. In 2001, a bolide event was proposed for the Permian extinction with great fanfare, but it does not appear to be related to the Permian extinction; the other dynamics would have been quite sufficient. The Permian extinction was the greatest catastrophe that Earth’s life experienced since the previous supercontinent existed in the .