Tutor profile: Carlos S.
Subject: Natural Sciences
What is allopatric speciation?
Allopatric speciation is the process by which one species becomes two or more species due to geographic isolation. This can be due to vicariant events such as the rising of a mountain, or forming of a rift. It can also be caused due to isolation that results due to a random dispersal event that creates a new population in a far-away habitat.
Subject: Environmental Science
Explain two mechanisms that explain why sea-levels have risen due to climate change?
Sea level rises due to climate change can be attributed to increased water volumes in the seas and thermal expansion of these water bodies. As temperatures have increased around the globe, solid reservoirs of water such as glaciers and ice have melted leading to more water in the hydrosphere. Also, with increases in temperature, seas have expanded due to the absorption of heat.
Define evolution. Is natural selection synonymous to evolution?
Evolution is broadly defined as changes in the genetic composition of a population (in other words gene pool) over time. It can be the result of several mechanisms, including mutation, genetic drift, gene flow, non-random reproduction, and natural selection. As natural selection is only one mechanism by which evolution can occur, it is not synonymous with evolution. In other words: natural selection can cause evolution, but a population can evolve without natural selection.
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