Identify and analyze the way fossil fuel combustion has changed the composition of Earth's atmosphere, and the way this change has affected climate.

the bald eagle got 50 because everything gets 10% of what they consume and since 50 is ten % of 500 hundred that means the   grasshopper had to have consumed a plant with 5,000 calories of energy

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.