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All over the world, there are fossils waiting to be discovered. However, they are so hard to find that we only have found about a truck load. Paleontology is the study of life which is through fossils.
A common misconception about fossils is how they are formed or made. Fossils are not bones, they are minerals which over time form into rocks. To begin with, the animals bones are eventually buried under soil. Through the soil minerals from water seep through resulting in the bone becoming a mineral. With the eventual addition of pressure from the soil, the mineral will harden into rock. Fossils can completely change a Paleontologists views or a hypothesis of how life was in the past. It is the evidence of the past. The evidence of evolution.
"Paleontology." Earth Sciences for Students. Detroit: Macmillan Reference USA, 2010. Gale Science In Context. Web. 11 Apr. 2011.
Radiometric dating:
“All radiometric dating is based on the fact that a radiometric substance, through its characteristic disintegration, eventually transmutes into a stable nuclide.”
Radiometric dating is an efficient way for scientists to discover a fossil or rocks age. It works like popcorn- begins slow, rapidly speeds up, then slows again and eventually stops. So how does this work? Lets take Uranium for example. Overtime, Uranium atoms eventually “transmute” into a more stable atom, Lead. Scientists compare the amount Uranium ions to the amount Lead atoms to discover a rock/fossils half-life. The more Lead there is, the older the specimen. With this knowledge, it opens up a world of opportunities for scientists to discover and explore.
"Radioactive dating." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 4th ed. Detroit: Gale, 2011. Gale Science In Context. Web. 12 Apr. 2011.
Biogeography:Why do different species live in the area(s) they do now? “Biogeography is the study of why plant and animal species live in different regions of the Earth.” It is split into two different categories. Historical (past history and evolution of a species) and also Ecological (a species environment).
“Biogeographers explain the distributions of species using four basic principles regarding the nature of Earth and the organisms that live on it:
Environmental variability: For a variety of reasons, the conditions that organisms experience change considerably across the surface of the Earth. Climate and elevation are two major influences.
Ecological limitation: Every organism has a limited range of conditions that must be met in order to allow it to live and reproduce. Since a species is a population of reproductively compatible organisms that have similar biological properties, no species can be found everywhere.
Continental drift: The locations of landmasses across Earth's surface have not remained the same, but have changed slowly over the geological history of the Earth. Therefore, the conditions experienced by organisms change over long periods.
Evolutionary change: Species do not stay the same over time, but are in a constant state of change as individuals best able to survive and reproduce within certain environments become more frequent, while others less capable die or fail to produce offspring. The ability of a species to evolve allows it to persist over long periods of time and track the changes occurring on the surface of the Earth.”
"Biogeography." Biology. Ed. Richard Robinson. New York: Macmillan Reference USA, 2009. Gale Science In Context. Web. 13 Apr. 2011.
For Example:
The Biogeography of the Tiger Salamander (Ambystoma Tigrinum):
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