<span>1. What is an endotherm?
Endotherm is an animal that keeps their temperature constant in a certain range. Keeping temperature is important because most enzyme has an optimal working range. By keeping the temperature at optimal range for the enzyme, the organism can do metabolism more efficient.
2. how do sweating, fur, and feathers affect the body temperatures of endotherms?
The environments temperature should influence the temperature of an organism that lives within it. </span>Endotherms need to control their temperature, so they have some mechanism to increase/decrease the body temperature. or to insulate themselves from the environment.
Sweating help decreasing temperature makes the organism can withstand hot environment. Fur and feather will insulate the body, makes the organism more resistant to cold.<span>
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Darwin’s Finches: Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources. This illustration shows the beak shapes for four species of ground finch: 1. Geospiza magnirostris (the large ground finch), 2. G. fortis (the medium ground finch), 3. G. parvula (the small tree finch), and 4. Certhidea olivacea (the green-warbler finch) the Grants measured beak sizes in the much-reduced population, they found that the average bill size was larger. This was clear evidence for natural selection of bill size caused by the availability of seeds. The Grants had studied the inheritance of bill sizes and knew that the surviving large-billed birds would tend to produce offspring with larger bills, so the selection would lead to evolution of bill size. Subsequent studies by the Grants have demonstrated selection on and evolution of bill size in this species in response to other changing conditions on the island. The evolution has occurred both to larger bills, as in this case, and to smaller bills when large seeds became rare.
