What causes large amounts of air to move?

There is a term "atmospheric circulation". It is when the air throughout the globe moves around. When the sun heats air near the equator more, and less at the poles. So the equator is warmer. The warm air near the equator moves either towards the south or the north, toward the poles. The warm air also rises up, and the cold air sinks. This is convection, but at a global scale. THis is also the cause of wind.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.